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Acceleration
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Discussion Starter #1
What would cause all of the lights on the car to turn on when the car is started, but function correctly when the car is off or in the on position but not started? When I crank the car and it starts up, the headlights pop up and turn on, the parking lights turn on, all the interior guage lights turn on, and the taillights turn on.

Also, related or not, when there is a load put on the engine whether it's high rpms or a lot of throttle, all the lights cut out and the headlights flip down. Then, when the load is released or the rpms drop down, the headlights flip back up and all the lights turn back on. I'm guessing this is related to the battery being overcharged, because the battery I'm currently running has been venting and the acid accumulates on the positive terminal of the battery, and the owner of a battery shop said thats definetely over charging. Problem is, I don't know what's causing it, or if it's related to the rest of the lights problem.

ALSO, when the car is started, the headlight switch is reversed. If I turn the switch to the normal headlights on position, all the lights on the car turn off, it's basically backwards.

HELP
 

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What would cause all of the lights on the car to turn on when the car is started, but function correctly when the car is off or in the on position but not started? When I crank the car and it starts up, the headlights pop up and turn on, the parking lights turn on, all the interior guage lights turn on, and the taillights turn on.

Also, related or not, when there is a load put on the engine whether it's high rpms or a lot of throttle, all the lights cut out and the headlights flip down. Then, when the load is released or the rpms drop down, the headlights flip back up and all the lights turn back on. I'm guessing this is related to the battery being overcharged, because the battery I'm currently running has been venting and the acid accumulates on the positive terminal of the battery, and the owner of a battery shop said thats definetely over charging. Problem is, I don't know what's causing it, or if it's related to the rest of the lights problem.

ALSO, when the car is started, the headlight switch is reversed. If I turn the switch to the normal headlights on position, all the lights on the car turn off, it's basically backwards.

HELP
im sorry but... lmfao :wtflol: your supra is dislexic
 

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Done? It's never done!
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by any chance do you have the 3 piece spoiler LED light on the N/A light relay (behind left tailight lense under the trim)? If my memory serves me right, your car was an N/A like mine before you did the swap. When I put the 3 piece spoiler onto the car, I had all these wierd problems with lights turning on and behaving wierd. Eventually the relay burned out and none of my lights worked. At which point, I ended up buying the relay for the late model turbo Supra. That fixed the problem for me.
 

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2JZ NA-T MKIII
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I've had my car do weird things like this when it had a bad ground from the battery, also when my alternator was on the way out. The headlight thing happened with a bad ground, but the load thing sound like alternator.

That being said I think it has to do with the charging system, moreso than a bad relay or wiring issue.. but thats jut my $.02
 

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wouldn't be the charging system as the higher the rpms got the more power the alt would produce. that is until it stops working...let alone in low rpms it would run off of the battery and everything would get dimm but not die flat out.his alt could be dead but he would have to boost his car every time he started. and nothing at all would work...assuming the car had enough power to run itself


i would check all your grounds as if you have poor grounds weird things can happen and i would check them now. having poor ground can lead to serious problems

i would also check that relay thing someone was talking about.
 

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Acceleration
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Discussion Starter #9
Well to give more info the alternator was checked and tested, and the wiring and harness was checked and tested.

tsupraspeed: Yes my car was NA before with the 3 piece spoiler. It used to work fine, but while the car was undergoing a 1jz swap this problem arose. Supposedly when the battery was first reconnected or power was given to the accessories there was a bit of smoke coming from behind the dash. I would like more info on this though, where is the relay you're talking about? Really sounds like that could be the problem.

Thanks for all the help so far guys! :)
 

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Done? It's never done!
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The taillight relay is located behind the driver's side taillight. If you just want to find it without removing it, you can take that light access cover off on the driver's side rear. If you actually want to replace it or inspect it, you'll have to remove the center trim and then most of the screws on the side trim in the trunk (you don't necessarily have to remove the entire trim off the car (I just pulled it back a little and up, undid the bracket holding it, unplugged the wire and then opened it up.


Once you disassemble that taillight relay box (mine was yellow. turbo one that went it was red), look for any blacken or burnt spots. Mine was charred right next to the plug (note the discoloration on the circuit board). There was also a wierd smell in the car for a while too after the 3 piece spoiler install.

I would probably also examine the circuit board of the instrumentation cluster behind the dash too.
 

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That's not the taillight relay. It's the taillamp failure module. While they can be a pain I seriously doubt it's the cause of AGlobalThreat's problem.

AGlobalThreat, I'd get out the multimeter and TEWD and start testing wiring. The smoke thing has me thinking a wire has shorted. Then, I would move to the Integration Relay #2:
http://www.cygnusx1.net/Supra/Library/TEWD/MK3/manual.aspx?Section=Main&Page=060

Make sure to compare your test results with the Service Hints here:
http://www.cygnusx1.net/Supra/Library/TEWD/MK3/manual.aspx?Section=Main&Page=61
 

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right under your dash is a box about as big as a pack of cigarettes, I bet that's the issue

if the relay failed closed, it would do this, if it failed open, it would cause the issues I had (so I'm not talking out of my ass here, been there, done that with this issue)
 

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Also, related or not, when there is a load put on the engine whether it's high rpms or a lot of throttle, all the lights cut out and the headlights flip down. Then, when the load is released or the rpms drop down, the headlights flip back up and all the lights turn back on. I'm guessing this is related to the battery being overcharged, because the battery I'm currently running has been venting and the acid accumulates on the positive terminal of the battery, and the owner of a battery shop said thats definetely over charging. Problem is, I don't know what's causing it, or if it's related to the rest of the lights problem.

HELP
Judging by that check out your voltage regulator, its a good time to replace the brushes too IMO....
 

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Acceleration
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Discussion Starter #15
The voltage on the battery did not exceed 14.7 through the entire RPM range

I will check out the taillight failure box and the box under the dash.
 
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