My very own wiring nightmare

poon

poon

E. Honda
May 23, 2007
37
0
0
37
florida
Well.. i have been an mk3 owner for nearly a month now...and it SUCKS. The car is a complete wiring nightmare and i have yet to be able to even get it on the road. The previous owner did a complete hackjob of nearly everything on the car, honestly im surprised it made it on the drive over to my house.

Anyways, enough of my bitching.. the wiring. All of fuses have been replaced, and i have been re-wiring as many things as i can but i have yet to find a few gremlins..

As of now when i hit the brakes, the radio cuts out and the lights dim. Also, the oem gauges will not light up and when i press the power window window to go up the interior lights dim, and they dont move or make a sound.

These problems lead me to believe that there is a screwy ground/grounds or something is missing power or a bad relay. I'm not sure where to check though, anybody have a clue to what the culprit may be?

Sorry for the rant
 
Yellow 13

Yellow 13

Lurker
Apr 4, 2006
2,308
0
36
Fairfield, California
Why do posts always come like this always come after its too late.

I just threw away a whole Supra body harness (front to back) because I couldnt find anyone who needed it.

Anyways, when it comes to serious electrical problems and my cars I always take it to the dealership and let them handle it.
 
Dirgle

Dirgle

Conjurer of Boost
Mar 30, 2005
1,632
0
36
42
Pauma Valley, CA
Are you sure you have a solid charging system. If not, take it to checker, napa whatever and get it checked. A poor or weak charging system can generate ghost's in the cars electrical system.
 
poon

poon

E. Honda
May 23, 2007
37
0
0
37
florida
IJ. said:
I predict many hours with a test light a multimeter and a wiring diagram in your future Lad ;)
Click to expand...

Indeed. Does anyone have any tips for some "usual suspects" i should check out? I'm confident i can get the car up to tip-top shape, its just time consuming :1zhelp:
 
poon

poon

E. Honda
May 23, 2007
37
0
0
37
florida
I have a multimeter / testlight as well as a bunch of wiring/soldering tools. Expierence with electronics? Aside from automotive, basically none. But, i am more than familair with the ins and outs of wiring.
 
poon

poon

E. Honda
May 23, 2007
37
0
0
37
florida
Dirgle said:
Are you sure you have a solid charging system. If not, take it to checker, napa whatever and get it checked. A poor or weak charging system can generate ghost's in the cars electrical system.
Click to expand...

Thanks for the solid advice.
 
3p141592654

3p141592654

90T
Oct 11, 2005
3,816
16
38
Thousand Oaks, CA
Good, then lets take a look at the stop lights.

The basic circuit is trivial, if you ignore the failure sensor for the moment.
http://www.cygnusx1.net/Supra/Library/TEWD/MK3/manual.aspx?Section=Main&Page=074

Note that the source of power to the stop lights is the STOP fuse located in the left kick panel junction box #1.
http://www.cygnusx1.net/Supra/Library/TEWD/MK3/manual.aspx?Section=Main&Page=16

You need to get your meter in there and monitor the voltage on pin 11 of connector 1L. When you hit the brakes measure the voltage (careful this has 12V all the time).

Now move to pin 3 of connector 1A (this is the main supply line to the junction box from the battery) and measure the voltage with the brakes on.
http://www.cygnusx1.net/Supra/Library/TEWD/MK3/manual.aspx?Section=Main&Page=036

Report back with your data.
 
poon

poon

E. Honda
May 23, 2007
37
0
0
37
florida
Sweet deal, diagrams and all. I'm sure this will start the detective work for the brake situation. Much appreciated, ill check it out asap and get an update
 
poon

poon

E. Honda
May 23, 2007
37
0
0
37
florida
hellraiser456 said:
make sure everything is grounded well too. if the electricity has to find a way to ground it will...and strange things happen.
Click to expand...

Which grounds should i be checking? I have gone over the engine grounds and they are all secure and clean, what else should i double check? Anything in the cab i should look at?
 
3p141592654

3p141592654

90T
Oct 11, 2005
3,816
16
38
Thousand Oaks, CA
poon

poon

E. Honda
May 23, 2007
37
0
0
37
florida
On the first diagram you just posted, where would i find the ground for the power windows master sw ?
 
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