I've gone through 15, 30a window motor fuses in a week!!!
#1
I've gone through 15, 30a window motor fuses in a week!!!
my car keeps burning the 30a window motor fuse.. every time i drive i burn one.. it will roll the windows up and down for about 1 minute, and then burn out and stop working
i took the door panel off and looked for a short or anything that would cause this, but found nothing.. all the other fuses are working and unburned.. what the f*ck?
i pretty much have to put a new fuse in every time i drive my car. help
i took the door panel off and looked for a short or anything that would cause this, but found nothing.. all the other fuses are working and unburned.. what the f*ck?
i pretty much have to put a new fuse in every time i drive my car. help
#4
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You have a short somewhere. Super ultra BASIC electrical diag 101
1. Get a wire diagram
2. Get a volt meter
3. Trace your grounds on the wire diagram
4. Connect one volt meter probe to a 12v source and use the other probe to check for an available ground at ur ground points on the circuit. A good ground will show you source voltage, anything significantly less implies high resistance/ bad ground.
In all honesty you have a bad ground somewhere, if you don't show to have a ground after checking, trace your ground wire to its grounding source, look for kinks in the wire or corrosion , which would give it high resistance causing a bad ground and blowing your fuse.
You can also check the continuity of your ground wire, but I don't know what your skill level is with electrical diagnosis. You can PM if you have any other questions. Good luck
1. Get a wire diagram
2. Get a volt meter
3. Trace your grounds on the wire diagram
4. Connect one volt meter probe to a 12v source and use the other probe to check for an available ground at ur ground points on the circuit. A good ground will show you source voltage, anything significantly less implies high resistance/ bad ground.
In all honesty you have a bad ground somewhere, if you don't show to have a ground after checking, trace your ground wire to its grounding source, look for kinks in the wire or corrosion , which would give it high resistance causing a bad ground and blowing your fuse.
You can also check the continuity of your ground wire, but I don't know what your skill level is with electrical diagnosis. You can PM if you have any other questions. Good luck
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And Hollow, a bad ground means increased resistance in the circuit. Which means less current flow, not more. A bad ground would cause the motor to not work all the time, or to perform poorly.
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#8
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Yes I said high resistance which mean less voltage and higher amperage, never said more current flow. And when that amperage exceeds the fuse, it blows so he doesnt melt wires. Honestly, he needs a wire diagram of the circuit and needs to bust out a multi meter. Do a voltage drop on your window switch to see what the load is while the switch is in operation. Do a voltage drop on the window motor as well. Also he may have an intermittent bad ground, with as old as these cars are, he may have several issues.
If you lived near Dallas, I'd be more than willing to help you diagnose this at my shop.
If you lived near Dallas, I'd be more than willing to help you diagnose this at my shop.
#9
Hey...Cut it out!
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Tachikoma, If said motor performed poorly, it would be moving slower than normal. If you recall Aaron Cake's E-fan articles, an electric motor has its greatest current draw at 0 RPM. Poor connections are why I was having issues with the starter in my 20B FC build. It would crank slowly, then trip the 150A breaker in 10 seconds. The solution was to go through the car, check every connection and resolder cables where needed.
Poor or corroded connections, either positive or ground, would increase the current draw in this manner as well. This is what Ohm's Law is about: V=IR
Voltage = Current (in amps) x Resistance (in ohms)
Corrosion on a connection increases the resistance, so the motor draws more power to compensate and it blows the fuse once it draws more than 30 amps every time. Read the following article about Ohm's Law and it will make more sense: http://www.aaroncake.net/rx-7/grounding.htm
What I would do is check & clean the window switches first, then the motor grounds. The switches carry the whole load of the motors' current draw and carbon up from the excessive arcing pretty badly over the years. The proper fix is to add two relays and some new wiring. This puts the load on a cheap replaceable relay that's made to handle 40 amps instead of the much more expensive window switches.
While you have the door panel off, it would be a good idea to test the motor alone. The way it works is that if you apply 12v on one side and ground on the other, it runs one way. Reverse the connections and it runs the opposite way. This is essentially what the window switches do and is called a DPDT Reversing switch in electrical terms. That is short for Double Pull Double throw. Easiest way to explain it is that it has two inputs (the "Pulls" and for each one of those inputs, it has two outputs (the "Throws"). Six terminals total. Reversing switches have two of the outputs connected together, but I cannot recall exactly how. Google will have the answer though.
Poor or corroded connections, either positive or ground, would increase the current draw in this manner as well. This is what Ohm's Law is about: V=IR
Voltage = Current (in amps) x Resistance (in ohms)
Corrosion on a connection increases the resistance, so the motor draws more power to compensate and it blows the fuse once it draws more than 30 amps every time. Read the following article about Ohm's Law and it will make more sense: http://www.aaroncake.net/rx-7/grounding.htm
What I would do is check & clean the window switches first, then the motor grounds. The switches carry the whole load of the motors' current draw and carbon up from the excessive arcing pretty badly over the years. The proper fix is to add two relays and some new wiring. This puts the load on a cheap replaceable relay that's made to handle 40 amps instead of the much more expensive window switches.
While you have the door panel off, it would be a good idea to test the motor alone. The way it works is that if you apply 12v on one side and ground on the other, it runs one way. Reverse the connections and it runs the opposite way. This is essentially what the window switches do and is called a DPDT Reversing switch in electrical terms. That is short for Double Pull Double throw. Easiest way to explain it is that it has two inputs (the "Pulls" and for each one of those inputs, it has two outputs (the "Throws"). Six terminals total. Reversing switches have two of the outputs connected together, but I cannot recall exactly how. Google will have the answer though.
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Tachikoma, If said motor performed poorly, it would be moving slower than normal. If you recall Aaron Cake's E-fan articles, an electric motor has its greatest current draw at 0 RPM. Poor connections are why I was having issues with the starter in my 20B FC build. It would crank slowly, then trip the 150A breaker in 10 seconds. The solution was to go through the car, check every connection and resolder cables where needed.
#13
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I'm having a very similar problem with my windshield wipers/fuse.
They work w/they key to acc, but they move slowly on all speeds. Not the same speed, but rather a fraction (2/3 lets say) of the speed they should be moving. The wiper switch works on all speeds, and I even swapped in another switch, and got the same results.
If the car is on and I try to use the writers they will work for a while but eventually the fuse will blow, this apparently happens even if the wipers are not used since the last fuse was installed.
The only recent changes (they used to operate at full speed and would only blow a fuse occasionally) is that I painted my engine bay and wiper motor.
They work w/they key to acc, but they move slowly on all speeds. Not the same speed, but rather a fraction (2/3 lets say) of the speed they should be moving. The wiper switch works on all speeds, and I even swapped in another switch, and got the same results.
If the car is on and I try to use the writers they will work for a while but eventually the fuse will blow, this apparently happens even if the wipers are not used since the last fuse was installed.
The only recent changes (they used to operate at full speed and would only blow a fuse occasionally) is that I painted my engine bay and wiper motor.
#15
Rotary $ > AMG $
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If not:
I would look for mechanical resistance, ie clean and lubricate the dirty tracks.
I would look for short.
I would clean the contacts on the switch.
I would install the relay modification.
If this were all done and the problem still happens, install a 30 amp self-resetting relay for a time to see if it solves the problem.
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