Meter 15A fuse keeps blowing
03-07-10, 04:10 PM
#26
8 posts within a matter of hours - minutes even - saying you don't know what the problem is doesn't help Alan. It's a good way to quickly increase your post count though 
Let's really try to help Alan out. Electrical problems are frustrating because so many circuits are in-line, making it difficult to determine which link in the chain is the one (<assumption) causing the problem. The symptoms are enough to start our brains turning (rotating
), but the more specifically you can describe the exact conditions when it blows, the more we can troubleshoot from the forum as we are not there with you and the car. Here's what you're told us:
1) The 15A fuse blows at higher rpm.
2) The same thing happens for a 20A fuse.
Based on this information, we can speculate that at this point that potentially
1) it's a weak ground, or
2) it's an intermittent ground.
If it's a weak ground, then increasing the rpm will increase the voltage from ~12.6 to 14.2 (~12% voltage increase), based on the assumption that your alternator's internal regulator is functioning properly in keeping the voltage within this range. Here's where a voltmeter comes in handy. Blowing a 20A fuse means that at there is at least an abnormal 33% voltage increase in that fuse line. However, faulty regulation would cause other fuses to blow as well. This may not be the exact root of the car's problem, but it eliminates that possibility.
You mentioned that the fuse blows at higher rpm. The motor will tend to vibrate more at higher rpm, and this may be causing a weak and/or intermittent short resulting in a blown fuse. If an exposed wire is also part of a loosely-tied bundle, bumps in the road may also be triggering the ground. Here's where electrical tape and zip ties come in handy.
At the higher rpm when the fuse blows, is the car stationary, or driving down the road? Is it lowered? Have you checked the harness for any frayed wires? The harness itself snakes underneath the left side fender and above tire. Because of the great location of the harness, on suspension compression, the tire can cut through the harness, introducing all kinds of electrical problems. If the harness is frayed, it takes just a little vibration for one wire to touch the one next to it - which would also be frayed - and this would introduce a voltage spike that would blow a fuse.
[I once had my pop-ups opening and closing by themselves on the freeway, before I repaired a frayed harness. Another time I had a relay constantly switching off and on while driving. All my wiring was clean and insulated, but the relay wire was laying right next to a positive center console wire, causing the electrons to be inducted into positive line. The fix involved simply moving one wire.]
How clean is your sound system installation and wiring?
The diagram AzEKnightz provided will help you follow the electrical path, and the FSM is stickied above this thread. Gen2n3's advice is good too. Start by following the harness and wiring as thoroughly as possible. Hopefully you can get to the bottom of it yourself. Otherwise consider taking it to a car stereo installation shop that you know to be the least shady. They should have all the tools to diagnose the short.
Let's really try to help Alan out. Electrical problems are frustrating because so many circuits are in-line, making it difficult to determine which link in the chain is the one (<assumption) causing the problem. The symptoms are enough to start our brains turning (rotating
), but the more specifically you can describe the exact conditions when it blows, the more we can troubleshoot from the forum as we are not there with you and the car. Here's what you're told us:1) The 15A fuse blows at higher rpm.
2) The same thing happens for a 20A fuse.
Based on this information, we can speculate that at this point that potentially
1) it's a weak ground, or
2) it's an intermittent ground.
If it's a weak ground, then increasing the rpm will increase the voltage from ~12.6 to 14.2 (~12% voltage increase), based on the assumption that your alternator's internal regulator is functioning properly in keeping the voltage within this range. Here's where a voltmeter comes in handy. Blowing a 20A fuse means that at there is at least an abnormal 33% voltage increase in that fuse line. However, faulty regulation would cause other fuses to blow as well. This may not be the exact root of the car's problem, but it eliminates that possibility.
You mentioned that the fuse blows at higher rpm. The motor will tend to vibrate more at higher rpm, and this may be causing a weak and/or intermittent short resulting in a blown fuse. If an exposed wire is also part of a loosely-tied bundle, bumps in the road may also be triggering the ground. Here's where electrical tape and zip ties come in handy.
At the higher rpm when the fuse blows, is the car stationary, or driving down the road? Is it lowered? Have you checked the harness for any frayed wires? The harness itself snakes underneath the left side fender and above tire. Because of the great location of the harness, on suspension compression, the tire can cut through the harness, introducing all kinds of electrical problems. If the harness is frayed, it takes just a little vibration for one wire to touch the one next to it - which would also be frayed - and this would introduce a voltage spike that would blow a fuse.
[I once had my pop-ups opening and closing by themselves on the freeway, before I repaired a frayed harness. Another time I had a relay constantly switching off and on while driving. All my wiring was clean and insulated, but the relay wire was laying right next to a positive center console wire, causing the electrons to be inducted into positive line. The fix involved simply moving one wire.]
How clean is your sound system installation and wiring?
The diagram AzEKnightz provided will help you follow the electrical path, and the FSM is stickied above this thread. Gen2n3's advice is good too. Start by following the harness and wiring as thoroughly as possible. Hopefully you can get to the bottom of it yourself. Otherwise consider taking it to a car stereo installation shop that you know to be the least shady. They should have all the tools to diagnose the short.
03-07-10, 07:14 PM
#27
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8 posts within a matter of hours - minutes even - saying you don't know what the problem is doesn't help Alan. It's a good way to quickly increase your post count though
Let's really try to help Alan out. Electrical problems are frustrating because so many circuits are in-line, making it difficult to determine which link in the chain is the one (<assumption) causing the problem. The symptoms are enough to start our brains turning (rotating), but the more specifically you can describe the exact conditions when it blows, the more we can troubleshoot from the forum as we are not there with you and the car. Here's what you're told us:
1) The 15A fuse blows at higher rpm.
2) The same thing happens for a 20A fuse.
Based on this information, we can speculate that at this point that potentially
1) it's a weak ground, or
2) it's an intermittent ground.
If it's a weak ground, then increasing the rpm will increase the voltage from ~12.6 to 14.2 (~12% voltage increase), based on the assumption that your alternator's internal regulator is functioning properly in keeping the voltage within this range. Here's where a voltmeter comes in handy. Blowing a 20A fuse means that at there is at least an abnormal 33% voltage increase in that fuse line. However, faulty regulation would cause other fuses to blow as well. This may not be the exact root of the car's problem, but it eliminates that possibility.
You mentioned that the fuse blows at higher rpm. The motor will tend to vibrate more at higher rpm, and this may be causing a weak and/or intermittent short resulting in a blown fuse. If an exposed wire is also part of a loosely-tied bundle, bumps in the road may also be triggering the ground. Here's where electrical tape and zip ties come in handy.
At the higher rpm when the fuse blows, is the car stationary, or driving down the road? Is it lowered? Have you checked the harness for any frayed wires? The harness itself snakes underneath the left side fender and above tire. Because of the great location of the harness, on suspension compression, the tire can cut through the harness, introducing all kinds of electrical problems. If the harness is frayed, it takes just a little vibration for one wire to touch the one next to it - which would also be frayed - and this would introduce a voltage spike that would blow a fuse.
[I once had my pop-ups opening and closing by themselves on the freeway, before I repaired a frayed harness. Another time I had a relay constantly switching off and on while driving. All my wiring was clean and insulated, but the relay wire was laying right next to a positive center console wire, causing the electrons to be inducted into positive line. The fix involved simply moving one wire.]
How clean is your sound system installation and wiring?
The diagram AzEKnightz provided will help you follow the electrical path, and the FSM is stickied above this thread. Gen2n3's advice is good too. Start by following the harness and wiring as thoroughly as possible. Hopefully you can get to the bottom of it yourself. Otherwise consider taking it to a car stereo installation shop that you know to be the least shady. They should have all the tools to diagnose the short.
Let's really try to help Alan out. Electrical problems are frustrating because so many circuits are in-line, making it difficult to determine which link in the chain is the one (<assumption) causing the problem. The symptoms are enough to start our brains turning (rotating
), but the more specifically you can describe the exact conditions when it blows, the more we can troubleshoot from the forum as we are not there with you and the car. Here's what you're told us:1) The 15A fuse blows at higher rpm.
2) The same thing happens for a 20A fuse.
Based on this information, we can speculate that at this point that potentially
1) it's a weak ground, or
2) it's an intermittent ground.
If it's a weak ground, then increasing the rpm will increase the voltage from ~12.6 to 14.2 (~12% voltage increase), based on the assumption that your alternator's internal regulator is functioning properly in keeping the voltage within this range. Here's where a voltmeter comes in handy. Blowing a 20A fuse means that at there is at least an abnormal 33% voltage increase in that fuse line. However, faulty regulation would cause other fuses to blow as well. This may not be the exact root of the car's problem, but it eliminates that possibility.
You mentioned that the fuse blows at higher rpm. The motor will tend to vibrate more at higher rpm, and this may be causing a weak and/or intermittent short resulting in a blown fuse. If an exposed wire is also part of a loosely-tied bundle, bumps in the road may also be triggering the ground. Here's where electrical tape and zip ties come in handy.
At the higher rpm when the fuse blows, is the car stationary, or driving down the road? Is it lowered? Have you checked the harness for any frayed wires? The harness itself snakes underneath the left side fender and above tire. Because of the great location of the harness, on suspension compression, the tire can cut through the harness, introducing all kinds of electrical problems. If the harness is frayed, it takes just a little vibration for one wire to touch the one next to it - which would also be frayed - and this would introduce a voltage spike that would blow a fuse.
[I once had my pop-ups opening and closing by themselves on the freeway, before I repaired a frayed harness. Another time I had a relay constantly switching off and on while driving. All my wiring was clean and insulated, but the relay wire was laying right next to a positive center console wire, causing the electrons to be inducted into positive line. The fix involved simply moving one wire.]
How clean is your sound system installation and wiring?
The diagram AzEKnightz provided will help you follow the electrical path, and the FSM is stickied above this thread. Gen2n3's advice is good too. Start by following the harness and wiring as thoroughly as possible. Hopefully you can get to the bottom of it yourself. Otherwise consider taking it to a car stereo installation shop that you know to be the least shady. They should have all the tools to diagnose the short.
I'll go and check the actual harness right now, as the car is lowered on TEIN coilovers and it does scrap on hard rights (when the wheel on the driver side go inside, obviously).
As for when the fuse blows out: at first, the fuse had blown out every 5 minutes or so (happened twice). I noticed that the second blowout happened exactly at the moment I was accelerating and hit about 3500 RPM. Yesterday, when I went to check my dimmer switch (from the posts previous, I was under the assumption that it could be the switch, but turns out not to be), I replaced the fuse after the checkup, and turned on the lights. The lights were back on and perfectly fine, I then started the car and even then the lights were fine. I tried to put some intermittent stress on the electrical system by revving the car in neutral and turn the lights on and off to see if I could get a spike or something. The lights stayed on (fuse was good, obviously) for the 10 minutes that I had the car idling. I decided to drive it around to see what would happen and as soon as I put the car in reverse, and let off the clutch slowly, the fuse blew out. I'm not sure what this means but could it be related to the fact that the engine has a load in gear?
As for the sound system, it appears to be a very clean job from what I can see. The previous car owner is shinchrono from these forums so I'm not sure how the sound system was installed. It does have an 800W amp with what looks like a 12" sub.
Another symptom that I've been seeing with the car is that the lights dim whenever I put some sort of electrical load on it. For example, I could have the headlights on, and my stereo on, and the windows would come down slower than if I had the other stuff off. The interior lights also dim with I put down the windows. This could mean that I just need a higher amperage alternator but could it also be related to this problem?
i had a problem when my meter fuse blew. As it turned out, there was a relay connector that shorted between two leads. I had to shine a light behind the connector to see it. Basically, the plastic dividing wall melted and caused a short. If you search for METER FUSE, you will see my posts.
There could be a few problem areas to check. First, I would disconnect your reverse light switch. It is located on the transmission, driver side. Check to see if your fuse blows. If it doesn't, replace that switch.
Then I would inspect the fan control relays next to your air intake. Disconnect all relays from harness and shine a light behind each connector on the harness. You are looking for any abnormal positions of the wire contacts. If it appears they touch, then that is your culprit. I spliced a replacement connector from another club member. You may see some gunk inside these connectors so using some electrical cleaning spray will help. You can get it at local autoparts store or Wal-Mart, etc.
I would also disconnect JB-02 connector, after looking at this diagram. By disconnecting it, you isolate your tail lights wiring from your dash lighting. You may or may not have dash lighting once this is done. If your TAIL fuse still blows, at least you can trace it further back within the tail light diagram.
I hope this helps and keep us posted on your progress.
EDIT: See the link that resolved my METER Fuse problem
https://www.rx7club.com/showthread.p...ght=meter+fuse
There could be a few problem areas to check. First, I would disconnect your reverse light switch. It is located on the transmission, driver side. Check to see if your fuse blows. If it doesn't, replace that switch.
Then I would inspect the fan control relays next to your air intake. Disconnect all relays from harness and shine a light behind each connector on the harness. You are looking for any abnormal positions of the wire contacts. If it appears they touch, then that is your culprit. I spliced a replacement connector from another club member. You may see some gunk inside these connectors so using some electrical cleaning spray will help. You can get it at local autoparts store or Wal-Mart, etc.
I would also disconnect JB-02 connector, after looking at this diagram. By disconnecting it, you isolate your tail lights wiring from your dash lighting. You may or may not have dash lighting once this is done. If your TAIL fuse still blows, at least you can trace it further back within the tail light diagram.
I hope this helps and keep us posted on your progress.
EDIT: See the link that resolved my METER Fuse problem
https://www.rx7club.com/showthread.p...ght=meter+fuse
03-08-10, 02:26 AM
#29
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Well, I just drove a whole hour without it blowing out. I put it into reverse and backed out of my car pack and then I fixed the fuse on the side of the road. For the duration of the whole trip, I didn't put the car into reverse until I was parking when I got to my destination. The fuse blew out as I was parking and put it into reverse. It flickered on and off a few times in reverse and then eventually blew out in about 30 seconds.
After a whole day of checking what was suggested in the two above posts, I put isolating the reverse lights last (I know, what luck that it turns out to be the reverse lights), and then I was gonna miss my appointment so I didn't end up isolating the reverse lights. I'll give it a shot tomorrow night when I have time but for now, I think it's safe to say that it's got something to do with either the reverse lights themselves or the wiring to them. I'll update as soon as I work on the car tomorrow night.
After a whole day of checking what was suggested in the two above posts, I put isolating the reverse lights last (I know, what luck that it turns out to be the reverse lights), and then I was gonna miss my appointment so I didn't end up isolating the reverse lights. I'll give it a shot tomorrow night when I have time but for now, I think it's safe to say that it's got something to do with either the reverse lights themselves or the wiring to them. I'll update as soon as I work on the car tomorrow night.
03-08-10, 05:33 AM
#30
03-08-10, 06:35 AM
#31
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Well, I just drove a whole hour without it blowing out. I put it into reverse and backed out of my car pack and then I fixed the fuse on the side of the road. For the duration of the whole trip, I didn't put the car into reverse until I was parking when I got to my destination. The fuse blew out as I was parking and put it into reverse. It flickered on and off a few times in reverse and then eventually blew out in about 30 seconds.
After a whole day of checking what was suggested in the two above posts, I put isolating the reverse lights last (I know, what luck that it turns out to be the reverse lights), and then I was gonna miss my appointment so I didn't end up isolating the reverse lights. I'll give it a shot tomorrow night when I have time but for now, I think it's safe to say that it's got something to do with either the reverse lights themselves or the wiring to them. I'll update as soon as I work on the car tomorrow night.
After a whole day of checking what was suggested in the two above posts, I put isolating the reverse lights last (I know, what luck that it turns out to be the reverse lights), and then I was gonna miss my appointment so I didn't end up isolating the reverse lights. I'll give it a shot tomorrow night when I have time but for now, I think it's safe to say that it's got something to do with either the reverse lights themselves or the wiring to them. I'll update as soon as I work on the car tomorrow night.
Best of luck and let us know what you find.
03-08-10, 06:58 AM
#32
03-08-10, 08:08 AM
#33
I have 7 guages and my cd player tapped into this line for illumination, and I figured that could have been the cause. More current draw than stock. Thats my reason for trying a higher amperage fuse. Its been holding. This does not rule out another problem exist since I have noticed it has blown twice while reversing out my driveway when leaving home.
03-08-10, 11:03 AM
#36
Alan, instead of blowing fuses left and right. You can get a circuit breaker (rated 15amp). So once it blows, and cools down you will have the circuit again. So no more replacement fuses needed.
I would isolate the problem by disconnecting the reverse light switch and jumping the connector (power to ground) and see if the circuit breaker pops. If it does. The short is elsewhere, if not the reverse switch is bad.
Secondly, put the reverse light switch back and reconnect it. Then I would goto the reverse light, check both connectors and make sure no corrosion present that could be having a potential shortage. And test this one side at a time. Disconnect one connector, jumper it. Go in the car, turn lights on and put in reverse. See if the breaker pop or not. If it does, problem elsewhere, if not you've found the cause. Do this to both connector at reverse light.
If the above method does not work. And I noticed you've lowered the car and someone else stated that your harness can be rubbing from the tire. Check at your fender wells, make sure your tire did NOT rub any plastic off and can potentially causing shortage between circuits and wires and even grounding it intermittently.
After that, report back. I would like to help u figure this one out. But very hard since the car is not in front of me.
-AzEKnightz
I would isolate the problem by disconnecting the reverse light switch and jumping the connector (power to ground) and see if the circuit breaker pops. If it does. The short is elsewhere, if not the reverse switch is bad.
Secondly, put the reverse light switch back and reconnect it. Then I would goto the reverse light, check both connectors and make sure no corrosion present that could be having a potential shortage. And test this one side at a time. Disconnect one connector, jumper it. Go in the car, turn lights on and put in reverse. See if the breaker pop or not. If it does, problem elsewhere, if not you've found the cause. Do this to both connector at reverse light.
If the above method does not work. And I noticed you've lowered the car and someone else stated that your harness can be rubbing from the tire. Check at your fender wells, make sure your tire did NOT rub any plastic off and can potentially causing shortage between circuits and wires and even grounding it intermittently.
After that, report back. I would like to help u figure this one out. But very hard since the car is not in front of me.
-AzEKnightz
03-08-10, 11:04 AM
#37
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juicy josh,
bad/loose/intermittent grounds will not blow fuses. shorts to ground will, as will drawing to much current. Bad bulbs and socket shorts are pretty common issues and will blow fuses
bad/loose/intermittent grounds will not blow fuses. shorts to ground will, as will drawing to much current. Bad bulbs and socket shorts are pretty common issues and will blow fuses
03-08-10, 11:58 AM
#40
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I just found something really handy for diagnosing shorts =) Check it out
Circuit breaker testing kit
Circuit breaker testing kit
03-08-10, 12:19 PM
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03-08-10, 01:21 PM
#45
I have too experienced odd electrical problems. Turned out that the harness running from the driver (left) side of the transmission up over the transmission bell housing had gotten pinched and was shorting out with engine movement. Might be worth a peak.
Good luck,
Guy
Good luck,
Guy
06-03-11, 07:01 PM
#47
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How was this ever resolved? I am having a very similar problem.
My car was recently in an accident so I think it may have to do with my busted taillight... Will look more in to it but just curious if Alan resolved his issue.
My car was recently in an accident so I think it may have to do with my busted taillight... Will look more in to it but just curious if Alan resolved his issue.
06-03-11, 07:26 PM
#48
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Had completely forgotten about this thread! But yes, the problem was solved due to a bad wire and connections to my tail lights and my driver-side headlight. I think the other symptoms were coincidental but it might have had to do with the car moving suddenly (clutch out blowing the fuse, caused by the car moving and the wires either shorting on each other or on another exposed metal).
So yes, chiefboon, check out the whole connection for your taillight, just one small part of the wiring can cause serious headaches! I'm not particularly knowledgeable about the whole thing so I didn't catch my problems early on, but do your check so you don't have to blow a whole box of fuses like I did!
Happy to say that my car doesn't do this anymore but the engine did give out last December. In the process of getting rebuilt by Lucky 7 though!
So yes, chiefboon, check out the whole connection for your taillight, just one small part of the wiring can cause serious headaches! I'm not particularly knowledgeable about the whole thing so I didn't catch my problems early on, but do your check so you don't have to blow a whole box of fuses like I did!
Happy to say that my car doesn't do this anymore but the engine did give out last December. In the process of getting rebuilt by Lucky 7 though!
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