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Serious electrical problem. HELP??!!!


kosmic

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Right guys, got a major electrical problem with the car and really need your help.

 

Situation:

A few days ago, car got a flat battery (my fault) as i left the headlights on while stationary. No Problem, Got the car jump started and all was fine. Next morning battery seemed low and a mare to start but after a few turns it fired up a ok.

 

Couple of days ago, whilst out and about i stopped the car and turned off the ignition and withdrew the key, as soon as i did that the horns on the car went blaring constantly, tried banging the steering wheel to see if the button had stuck but no, so i ended up taking the fuse out for the horn under the engine compartment. Sorted for now.

 

Yesterday, went over a speed bump and both indicator arrows on the dash flashed briefly and then as i went to turn and signal...no indicators. Pulled over - blown fuse!! Changed that and everyting was fine.

 

Today, As i pulled into my drive and the ramp, car completely cut out, no alrm no ignition no nothing, completely dead. Checked everything and found the huge 50A POWER fuse in the engine compartment fuse box had blown. replaced that but now i have no power steering and the car wont shift out of P when you depress the brake pedal? I have to press that little red button to change into R N D. So i checked the interior fuses. FUSE 12 ELECTRONICS_ING which controls pwer steering ABS etc etc had blown. Replaced that and its blown again.

 

So i have a car on the drive, with no power steering, Slip contorl flashing like a mare, ABS light on, Both Outer headlight lights permantly ON when the switch is OFF on the control stalk and i cant shift into R N Djust by pressing the brake pedal. Oh and the indicator fuse has blown again!!! :swear: :swear: :swear:

 

I really need u elec boffins to help me out, Matt H or anyone. I cant see what the problem is. Whenever i change the Fuse 12 it keeps blowing. so does the trun signal fuse. whenever i go over a speed bump the Rh turn signal indicator on the dash briefly lights up.....HELP!!!!!!!!!!!

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I may be way off here , but I can't see how a jump start could cause all those problems. If 50amp fuse goes you have a significant fault, with all the others going as well, I would suspect an intermitment short somewhere. It sounds like a section of loom may be damaged.

 

When did you last have the dash apart?

 

But I am sure someone with a greater understanding of car eletrics will give you better things to look for.

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Thanks for the feedback guys, last time i had the dash apart was about 3 months ago. All these problems seemed to have started to occur when i had the flat battery situation. This morning, when i flicked the windscreen wipers on, the outer most lights in the headlights come on and only go off when you toggle the switch ON then OFF.....weird!!!

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I heard its not a good thing jumping a car but at the time when the battery was dead i kinda had no choice. Why is it so bad for the car??

It might be that the current draw from the car you got the jump start from into your battery would be fairly high and has damaged your battery and possibly other things.

 

When you charge a battery up using a charger you're only supposed to do it slowly.

 

I think you might have a problem with your battery, not sure if it's permanent or not but if it's still possible to charge it up and you haven't tried then it will be pretty lifeless after being totally drained.

 

The first thing I would do would be to get the battery checked out.

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To blow a 50amp fuse it is a VERY serious issue, most of the wiring loom would suffer with that kind of current and could result in bits of the loom going up in smoke....

 

I would get the alternator checked as it could be the regulator on it that has gone... and they are the reason why jumping is not recommended becuase it can cause them to fail...

 

I would be very careful and check the car fully....

 

The last time I had a serious fault like that was on an audi turbo, and it resulted in the wiring loom going up in smoke, the radiator fan seized and someone had put an over-rated fuse in the system... the loom melted and went up in flames... in the space of 2 mins the car was on fire and that was the end of that....

 

You can imagine the phone call I had to make to tell my dad his car was on fire... not fun.... but I made it up to him 2 weeks later when I crashed his brand new 328i when I popped out to get pizza...

 

Gav

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Tanks guys, just to add. Driving into work this morning replaced the fuse for the power steering ABS slip contorl etc etc, seemed fine. The as i went over a bump, the rh indictoar stayed permantley ON, i stopped and removed the fuse and the RH indicator lights are still ON???!! As i continued driving the OD light on the dash kept flashing. ARGHHHHHHHHHH!!!! This is so frustrating!!! Any more ideas??

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To blow a 50amp fuse it is a VERY serious issue, most of the wiring loom would suffer with that kind of current and could result in bits of the loom going up in smoke....

 

I would get the alternator checked as it could be the regulator on it that has gone...

 

Gav

 

Is the regulator built into the alterantor or a seperate unit?

I'm having similar problems afters having starting up problems on two occassions recently where the car battery has been connected to a charger and jump started.

Whilst driving I momentarily lose power to my stereo and boost gauge and the headlights become dim. If I'm stationary the revs go down too, this has always happened but never the power loss to the accessories or lights.

 

 

Sorry for the Hijacked thread! :hijack:

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As has been mentioned above, I would start by getting your alternator and battery checked out. I have seen alternator regulator packs blow before and they can cause alsorts of funny stuff to happen.

 

You also may of spiked a control unit or two by jumping the car. I have seen this done many a time. Also check you fuse boards, I have seen these melt before on other cars (never a Supra though) and they short themselves out and make things work when they shouldn't be.

 

There is no easy suggestion of what is the main cause here I am affraid mate, its going to take abit of time to trace and fix.

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As has been mentioned above, I would start by getting your alternator and battery checked out. I have seen alternator regulator packs blow before and they can cause alsorts of funny stuff to happen.

 

You also may of spiked a control unit or two by jumping the car. I have seen this done many a time. Also check you fuse boards, I have seen these melt before on other cars (never a Supra though) and they short themselves out and make things work when they shouldn't be.

 

There is no easy suggestion of what is the main cause here I am affraid mate, its going to take abit of time to trace and fix.

 

Can the alternator be checked in situ or does it need to be removed??

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IMO this is a bit tricky to diagnose on here. As already said to blow a 50a fuse is a bit drastic.

 

As Gav said, get the alternator checked. If you have a multimeter, check the voltage when the car is running. It should be around 14.4volts. Slightly more or less isn't a problem, but certainly not significantly over 15v.

 

I hate to say this, but going on your comment about the indicators sticking on even when the fuse is taken out, could mean that the alarm is playing about and possibly fried too. I'm fairly cartain it won't be related to headlights or the blowing of a 50a fuse, but it may be a case that you maybe have a couple of ECU's effected by the jump start.

 

Sorry, can't be much more help at the moment. Can't say I've ever come across anything like that with a Supra before. :(

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aahahahahaha classic

It was funny, until my dad's loan car arrived while the beemer was being fixed... it was a golf mk1 1.3

 

He was not impressed, and after I stopped laughing, he then smiled at me and informed me that I would have great pleasure in driving it.... turns out he had pinched the keys to my m3 and was driving that, leaving me with the golf for two weeks while it was in the bodyshop....

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IMO this is a bit tricky to diagnose on here. As already said to blow a 50a fuse is a bit drastic.

 

As Gav said, get the alternator checked. If you have a multimeter, check the voltage when the car is running. It should be around 14.4volts. Slightly more or less isn't a problem, but certainly not significantly over 15v.

 

I hate to say this, but going on your comment about the indicators sticking on even when the fuse is taken out, could mean that the alarm is playing about and possibly fried too. I'm fairly cartain it won't be related to headlights or the blowing of a 50a fuse, but it may be a case that you maybe have a couple of ECU's effected by the jump start.

 

Sorry, can't be much more help at the moment. Can't say I've ever come across anything like that with a Supra before. :(

 

Thanks Matt, but would it cause all sorts of different electrical circuits in the car to blow? Im goin to check the battery alternator voltage tonight when i get back. May fish around in the drivers footwell and see if i can remove the fusebox/board and see if theres any shorts there. I know the Clifford alarm thats in the car when i bought it has been extremely badly fitted. Although in 4 months of owning this car it has never let me down. The issues have started appearing after the flat battery scenario.

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No, never removed the battery...all connections are tight. Did notice one thing hoever before all this drama. the Drivers side indicator light/bulb (in the wing) had blown, dont know if this is shorting or something, as i never got around to changing it???!!

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The fact that it drives and when you go over a bump etc suggests to me an intermittent short. Be that an ECU internal one or an external wiring one. Could the alternator regulator going tits have cause the 50 amp fuse to blow? That aside for a 50 amp fuse to go a wire somewhere got very very warm. Its not unfeasable that some insulation got melted somewhere and now some wires are bare and touch each other occasionally like say when you go over a bump.

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According to MKIV.COM, if the fuses keep blowing frequently it is quite correctly saying the regulator could be defective?! Just trying to see how it could be linked to the indicator lights going ape when i going over bumps in the road?!

 

 

Mate, maybe you have melted/shorted wires?.... and when you go over bumps the bare wires may be touching?

 

My boost controller wires shorted once (due to heat after touching the turbo heatshield) but this took out alot of wires around the main ECU. I would take the cover off and have a look (Passenger footwell).

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I know this is a bit late, but it might save some others having problems.

 

If you ever have to jump start you car, don't connect the jump leads with your ignition on. If you want, take the key out of the ignition before connecting everything up to make extra sure nothing is turned on. Then and only then, turn the ignition on. Power spikes at the instant you connect the leads can cause all sorts of problems with the electronics.

 

This one is pretty odd as there seems to be lots of things going on at the same time. It does sound like there is mechanical movement going on because things happen going over bumps. Melted insulation does sound very possible, but it'll be a nightmare to find the problem if this is what it is.

 

Had any other work done lately?

 

I know IanC's car had some VERY odd symptoms a few years ago after the main engine earth lead worked loose.

 

Hope you find the problem.

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