Battery Discharge
01-08-10, 08:07 PM
#1
Battery Discharge
I have a 3.10A discharge on my battery. I pulled all the fuses, removed the wires from the starter and alternator, still in. I have isolated all loads that I installed (intercooler sprayer, wideband, e-fan, etc) but it's still there. Everything's off as far as I know, door's shut, no lights on, it just won't go away. Anyone know of anything else that could cause the short?
1988 convertible w/ 1987 TII engine & trans (NA harness)
1988 convertible w/ 1987 TII engine & trans (NA harness)
01-11-10, 03:16 PM
#2
New results:
I must have skipped it somehow, but after much frustration, I decided to start all over. I started pulling every fuse, and found that the 10A fuse that goes to the hazard lights is what's causing the current draw. NOW I have to figure out why!! The hazards aren't on, and wiring diagrams are ****-tay.
I must have skipped it somehow, but after much frustration, I decided to start all over. I started pulling every fuse, and found that the 10A fuse that goes to the hazard lights is what's causing the current draw. NOW I have to figure out why!! The hazards aren't on, and wiring diagrams are ****-tay.
01-11-10, 04:43 PM
#3
Fuses 2&3, so it's the 10a hazards, AND the 7.5 room fuse. I disconnected the c.p.u., which houses the flasher (near the fuse block), and the anti-theft controller (under glovebox), since that's what both fuses have in common. Still got the 3.10A drain.
Anyone?
Anyone?
01-11-10, 04:54 PM
#4
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Hazard and Room fuse are both on the Battery buss in the interior fuse box.
The battery bus in the interior is fed from the BTN fuse in the engine bay.
If someone spliced a new wire/component to either of these items, then that new item might be the culprit.
Like if someone spliced a wideband power wire to the pin 3J of the small ECU plug, that item might be the thing causing the problem. 3J gets power from the room fuse via the BTN fuse. The car will run just fine without the 3J getting any power whatsoever.
Pulling the BTN fuse should kill everything that is on the batt bus.
Always make sure the ignition key is to OFF and not left in AUX when the key is removed.
The battery bus in the interior is fed from the BTN fuse in the engine bay.
If someone spliced a new wire/component to either of these items, then that new item might be the culprit.
Like if someone spliced a wideband power wire to the pin 3J of the small ECU plug, that item might be the thing causing the problem. 3J gets power from the room fuse via the BTN fuse. The car will run just fine without the 3J getting any power whatsoever.
Pulling the BTN fuse should kill everything that is on the batt bus.
Always make sure the ignition key is to OFF and not left in AUX when the key is removed.
01-11-10, 06:44 PM
#5
It's too dark/cold now, but I'll check that tomorrow. It's been a while since I installed my NGK wideband and SAFC, but I pulled out my old schematics (handwritten notes on them 
) and I THINK that the SAFC has power from pin 3I. Otherwise, wouldn't pin 3J keep the SAFC on always?
I'll have to check out what the NGK powerdex is powered by.
Where's a good wiring schematic for the battery bus? The mitchell's schematic is pretty clear, but I can't find this battery bus you're talking about, and the FSM schematic..... well....
) and I THINK that the SAFC has power from pin 3I. Otherwise, wouldn't pin 3J keep the SAFC on always? I'll have to check out what the NGK powerdex is powered by.
Where's a good wiring schematic for the battery bus? The mitchell's schematic is pretty clear, but I can't find this battery bus you're talking about, and the FSM schematic..... well....
01-11-10, 07:42 PM
#6
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Not colored in the attachment is the power from the 80a Main fuse to the two circuit breakers on the top of the interior fuse box. I think they are for window defrost power or the like. They are also on the battery bus as shown in the attachent from the online wiring diagrams for the series four cars. Series five similar.
The cable that goes b/t the alternator (large output cable) and engine bay fuse box is also spliced to the pure black wire that feeds the ignition switch. As shown in the attachment.
The cable that goes b/t the alternator (large output cable) and engine bay fuse box is also spliced to the pure black wire that feeds the ignition switch. As shown in the attachment.
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01-12-10, 07:22 PM
#8
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If you pull the 7.5a Room fuse do you lose the drain?
If you pull the 10a Hazard fuse do you lose the drain?
Or how much of the drain do you lose when you pull just one of the above?
There will always be a drain as long as the Room fuse is in and feeding the ECU pin 3J. Not much of a drain. It's in milivolts for that item. When the ECU small plug is disconected that small drain will go away.
See how I'm confuse about which fuse is the problem? Which one? Both?
The only fuses that can cause a drain from the interior fuse box is those that are on the Batt bus. That would be the fuses on the top of the box I drew a red line around.
All those other fuse on IG1 and IG2 in my jpg, have power only when the key is put to ON or better....or key in Aux.
The two fuses Room and Hazard are on the batt bus so they could cause a drain. Actually key in OFF, there will be no drain on Hazard unless the hazard button is pushed. Room will cause a drain from the ECU with no action taken. Normal. Very small drain in miliamps.
3amps is a pretty large drain. You disconnected the CPU so it can't be from there.
If you look at the online wiring diagrams for the 88 cars, and look at say the THEFT page, you'll see at the top of that page about 5 lines. The are labled A...2....1.....S..and B. The B represents power coming from the battery bus.
So remembering that, look at the THEFT page and you'll see the B line with a number 9 with a 3 just to the right. Those two numbers represent power coming off the ROOM fuse on the Battery bus.
Taking that in mind, go look at all the pages in the wiring manual and look just at the B line. Where ever you see the 9 followed by a 3, is an item powered by the ROOM fuse. Most always a L/R wire.
Taking that in mind, go look at the RADIO pages and you see the B line with a 9 followed by a 3, indicating the radio also is a power sucker from the room fuse at times
There's several other pages with the B line with the 9 followed by a 3.
Go look at the beginning of the wiring diagrams that has a page like the jpg I attached in my other post. Find the B line at the top of the page and see how it goes down.....well look at the jpg attached on how it works.
If you pull the 10a Hazard fuse do you lose the drain?
Or how much of the drain do you lose when you pull just one of the above?
There will always be a drain as long as the Room fuse is in and feeding the ECU pin 3J. Not much of a drain. It's in milivolts for that item. When the ECU small plug is disconected that small drain will go away.
See how I'm confuse about which fuse is the problem? Which one? Both?
The only fuses that can cause a drain from the interior fuse box is those that are on the Batt bus. That would be the fuses on the top of the box I drew a red line around.
All those other fuse on IG1 and IG2 in my jpg, have power only when the key is put to ON or better....or key in Aux.
The two fuses Room and Hazard are on the batt bus so they could cause a drain. Actually key in OFF, there will be no drain on Hazard unless the hazard button is pushed. Room will cause a drain from the ECU with no action taken. Normal. Very small drain in miliamps.
3amps is a pretty large drain. You disconnected the CPU so it can't be from there.
If you look at the online wiring diagrams for the 88 cars, and look at say the THEFT page, you'll see at the top of that page about 5 lines. The are labled A...2....1.....S..and B. The B represents power coming from the battery bus.
So remembering that, look at the THEFT page and you'll see the B line with a number 9 with a 3 just to the right. Those two numbers represent power coming off the ROOM fuse on the Battery bus.
Taking that in mind, go look at all the pages in the wiring manual and look just at the B line. Where ever you see the 9 followed by a 3, is an item powered by the ROOM fuse. Most always a L/R wire.
Taking that in mind, go look at the RADIO pages and you see the B line with a 9 followed by a 3, indicating the radio also is a power sucker from the room fuse at times
There's several other pages with the B line with the 9 followed by a 3.
Go look at the beginning of the wiring diagrams that has a page like the jpg I attached in my other post. Find the B line at the top of the page and see how it goes down.....well look at the jpg attached on how it works.
01-12-10, 09:13 PM
#9
See, this confused me at first, too. I INITIALLY started pulling fuses one at a time, then replacing them as soon as I didn't see the draw go away. That's what I was going on my first post. THEN I thought it could be from 2 fuses, and sure enough, I started yanking them until it went away. THEN I went in the same order of replacing them, which is when I found ANOTHER fuse causing the same draw. I think you're right, the room fuse pulled, and hazard in, the draw goes down from 3.1A to about 2.99A. Not a real significant amount, but you get the picture.
So yes, BOTH have to be removed for the 3A draw to go away. Yeah, 3A is a pretty good draw. That's why I had to push start her 2x the other day to get home from work!!
I didn't get a chance to fool with it today, but tomorrow I should be able to figure some more out. I'm right now just trying to get a list together of all the **** I'm going to have to unplug to find this short!
So yes, BOTH have to be removed for the 3A draw to go away. Yeah, 3A is a pretty good draw. That's why I had to push start her 2x the other day to get home from work!!
I didn't get a chance to fool with it today, but tomorrow I should be able to figure some more out. I'm right now just trying to get a list together of all the **** I'm going to have to unplug to find this short!
01-13-10, 03:43 PM
#11
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The HAZARD fuse feeds but one thing. The CPU at the plug shown in the jpg attached. IF that plug is removed, then the HAZARD feeds nothing on a stock car. The only way it can cause a draw is if someone has tapped into it somewhere prior to the CPU.
The turn signals (inside the CPU) depend on the HAZARD fuse for them to operate so you can't just pull the HAZARD fuse and go on your merry way.
The turn signals (inside the CPU) depend on the HAZARD fuse for them to operate so you can't just pull the HAZARD fuse and go on your merry way.
01-13-10, 07:22 PM
#12
Yep. Already realized that. But the problem is real, and still exists! It's almost like it has to be something capacitive. When I pull both of the fuses, the drain goes away really slowly. Odd....
I agree, though. I have the CPU sitting in the driver's seat, and the draw still remains. And the car was completely unmolested until I got a hold of her, but I never put anything in that circuit. I have an SAFC and a wideband inside the car, and an E-Fan. That's it for electrical modifications. And all my jobs are professional. No botch-job wiring, it all gets soldered and heat shrink-wrapped.
I agree, though. I have the CPU sitting in the driver's seat, and the draw still remains. And the car was completely unmolested until I got a hold of her, but I never put anything in that circuit. I have an SAFC and a wideband inside the car, and an E-Fan. That's it for electrical modifications. And all my jobs are professional. No botch-job wiring, it all gets soldered and heat shrink-wrapped.
01-14-10, 12:11 AM
#14
wait, so your saying that after you pull the fuses, the current flow from the battery slowly diminishes? If that's the case, there is a capacitor betweem the interior fuse box, and the battery. Try pulling the main bus fuse. If current flow drops instanly, then your drain is betweem there and the interior box, if it still slowly diminishes then the problem lies between the battery and the power side of the main fuse.
on a side note, I'm doing this from my phone so I can't see the diagrams posted, or I could help more.
on a side note, I'm doing this from my phone so I can't see the diagrams posted, or I could help more.
01-14-10, 05:09 PM
#16
So I just disconnected everything the Room Fuse powers. Turns out, it's the culprit... by itself. Don't know why the other day it looked like it was both, but it's not... at least not now.
Anyways, I have completely disconnected the:
Anti-theft module
CPU
Radio
Auto clock/warning module
ignition switch
Wait, I didn't unplug the ECU. Hailers, you hear this alot, but I think you're on the right track. We may have found our culprit!
I'm going to go try that now.
Nope, didn't work. Now I guess it's got to be inter-connecting wiring. SO.. I'll have to snip wires at the fuse block one by one until I find the problem.
Anyways, I have completely disconnected the:
Anti-theft module
CPU
Radio
Auto clock/warning module
ignition switch
Wait, I didn't unplug the ECU. Hailers, you hear this alot, but I think you're on the right track. We may have found our culprit!
I'm going to go try that now.
Nope, didn't work. Now I guess it's got to be inter-connecting wiring. SO.. I'll have to snip wires at the fuse block one by one until I find the problem.
01-16-10, 10:13 PM
#18
Don't care about that, I will NEVER drive any Rx7 as a DD. I just want it fixed 
Now, the schematics I've seen haven't shown other things that I know to be on the room fuse. For instance, as stated above, the interior lights! I also happen to know that the room fuse will definitely blow if the reverse switch is shorted. SO, this leads me to belive that there has to be more than just what the schematics are showing.
Now, the schematics I've seen haven't shown other things that I know to be on the room fuse. For instance, as stated above, the interior lights! I also happen to know that the room fuse will definitely blow if the reverse switch is shorted. SO, this leads me to belive that there has to be more than just what the schematics are showing.
01-17-10, 06:06 PM
#19
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You open the 88 wiring manual online and look at each page and in particular at the B line at the top. Where ever you see the number 9 followed by the number 3 (circled number), then that item is fed by the room fuse.
Radio.....theft controller..........ignition key reminder switch......warning cluster.....ECU pin 3J
OR cargo room light....courtesy lights.........interior and spot light.......warning buzzer chime, door lock cylinder and ignition key light........ECU......warning and auto clock unit.....theft system.......audio system
Seems with a 3A draw you'd see/hear/smell something going on.
Radio.....theft controller..........ignition key reminder switch......warning cluster.....ECU pin 3J
OR cargo room light....courtesy lights.........interior and spot light.......warning buzzer chime, door lock cylinder and ignition key light........ECU......warning and auto clock unit.....theft system.......audio system
Seems with a 3A draw you'd see/hear/smell something going on.
06-12-14, 09:47 AM
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hi, I'm not sure if i will be of some help but i may have slightly the same issue.
I don't know whats the magnitude of my draw but if i let the car in the garage for three weeks, the battery is too empty to start the engine.
what might be relevant, is that when my headlight is on, i always have the light for the fog light in the center panel half lit. If i turn on and off the fog light, the center panel light goes full lit then is off. and then it will come slowly half lit.
at first i thought it was a relay in issue in my wiper command (who apparently houses the a relay for the fog light command). as my wiper didn't worked anymore, i changed it for a refurbished one. The wiper worked again but the fog light is still half lit.
Maybe you could try to just put the headlight on and see if you also have the fog light half lit ?
I don't know whats the magnitude of my draw but if i let the car in the garage for three weeks, the battery is too empty to start the engine.
what might be relevant, is that when my headlight is on, i always have the light for the fog light in the center panel half lit. If i turn on and off the fog light, the center panel light goes full lit then is off. and then it will come slowly half lit.
at first i thought it was a relay in issue in my wiper command (who apparently houses the a relay for the fog light command). as my wiper didn't worked anymore, i changed it for a refurbished one. The wiper worked again but the fog light is still half lit.
Maybe you could try to just put the headlight on and see if you also have the fog light half lit ?
06-12-14, 10:36 AM
#23
hi, I'm not sure if i will be of some help but i may have slightly the same issue.
I don't know whats the magnitude of my draw but if i let the car in the garage for three weeks, the battery is too empty to start the engine.
what might be relevant, is that when my headlight is on, i always have the light for the fog light in the center panel half lit. If i turn on and off the fog light, the center panel light goes full lit then is off. and then it will come slowly half lit.
at first i thought it was a relay in issue in my wiper command (who apparently houses the a relay for the fog light command). as my wiper didn't worked anymore, i changed it for a refurbished one. The wiper worked again but the fog light is still half lit.
Maybe you could try to just put the headlight on and see if you also have the fog light half lit ?
I don't know whats the magnitude of my draw but if i let the car in the garage for three weeks, the battery is too empty to start the engine.
what might be relevant, is that when my headlight is on, i always have the light for the fog light in the center panel half lit. If i turn on and off the fog light, the center panel light goes full lit then is off. and then it will come slowly half lit.
at first i thought it was a relay in issue in my wiper command (who apparently houses the a relay for the fog light command). as my wiper didn't worked anymore, i changed it for a refurbished one. The wiper worked again but the fog light is still half lit.
Maybe you could try to just put the headlight on and see if you also have the fog light half lit ?
06-12-14, 11:13 AM
#25
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After researching I need to check that my series 6 alternator is wired properly for the series 4 harness as well. I read a thread on hear that stated the S4 and S5 harnesses require different terminals to be connected. Since the PO wired that up, I need to understand that is correct as well.
And I don't have fogs Gruns. Thanks for the suggestion though. Wiper switch has new relays in it as well.
