Dash lights and accessory lights went out...

[LexingtonBlue]

Has it happened to anyone before?

I accidentally caused a short in my cig lighter and made the clock go out, on my '89. Checked all the fuses in driver's fuse box, replace the CIG fuse and the clock turned back on. HOWEVER, I noticed that my dash lights (and heater accessory lights, other accessory lights) went out. They were working perfectly before I made the short circuit.

-brake lights, tail lights, head lights, turn signals, glove box, dome lights are still good, EXCEPT for the dash lights (gauge lights) and heater control lights are no good.

-The heater control lights works when the headlight/parking light/corner light switch is in the "off" position, but as soon as I turn the knob for headlights on, the heater control lights stayed on for not even a split second, then goes off.
:aigo: :aigo: :aigo: :aigo: :aigo: :aigo: :aigo: :aigo: :aigo: :aigo: :aigo: :aigo:

Things I've tried:
-replaced dimmer switch with a different one => still no work
-check fuses over and over and over => obviously no work
-guessed where the dash light wire is and somehow reroute it => still guessing...

Can anybody help me??!?! I can't see how fast I'm going at night, but feels like I am flying!

 

[MKIIINA]

SAME FREAKIN PROBLEM HERE!!!! everything works fine when the lights are off but turn on the running lights and i lose dash illumination and climate control. this did it before and randomly came back on when i popped off the section of the dash that has the dimmer, foglight switch and rear defroster.....help guys!

 

[bluemax]

OK I just posted a reply and had to re-log in and lost my post........

 

[bluemax]

OK. This is the third time .........
I'll try again.

The marker (running) lights and dash lights are on the same 15A TAIL fuse circuit.
http://www.cygnusx1.net/supra/library/TSRM/d/D_20.html
http://www.cygnusx1.net/supra/library/TSRM/d/D_21.html

The clock and cig power are in parallel, but in a separate circuit than the dash/marker light circuit.
http://www.cygnusx1.net/supra/library/TSRM/d/D_24.html

But there is an input from the 15A TAIL to the clock. I assume this is for illumination control, not for power.

I'd change the 15A TAIL fuse in Junction Block 1 first:
http://www.cygnusx1.net/supra/library/TSRM/be/BE_013.html
Located behind the drivers side kick panel:
http://www.cygnusx1.net/supra/library/TSRM/be/BE_010.html
The fuse is probably not the problem, but its easy and cheap.

Because the illumination of the dash and associated components are loosing power, I'd change the dash dimmer next. The dimmer might not be allowing enough current go to ground. That's not going to be cheap and not as easy.

LexingtonBlue, you clock may have been damaged by the short in the cig. So I'd disconnect the clock to see if that affects your situation.

 

[bluemax]

At last.........3s a charm.

 

[LexingtonBlue]

Will try it when I get back home!!!! Thanks!

 

[trydrew]

I have the same situation where only the lights above my climate control buttons (89+ style) light up, but go out when the marker lights are on. Also the backlights flash for a split second when you turn on the marker lights. I pulled out my dimmer switch and found a resistor was blown.

 

[LexingtonBlue]

ok update....

I don't know how to read wiring diagrams and I got confused there. I tried 2 other dimmer switches and nothing happened....

 

[3p141592654]

The dimmer rheostat is in series with the ground side of the circuit. I suspect you have an open circuit in the ground from the rheostat to the car body. If you have a DVM, disconnect the dimmer switch and check the resistance between the white-black wire (on dimmer connector attached to the car) and a good ground on the car body. Should be a short (~0 ohms).

If that's okay, then with the tail lights turned on, check the voltage on the green and white-green wires, should both be 12 V. Finally, short the white green wire to ground and the dash lights should come on full brightness. Let us know the results of these tests and we can go from there.

NOTE: colors are for 89+ cars, probably same for <89 models, but if the colors don't match don't proceed with tests above.

 

[chriso]

Integration relay???

 

[LexingtonBlue]

The dimmer rheostat is in series with the ground side of the circuit. I suspect you have an open circuit in the ground from the rheostat to the car body. If you have a DVM, disconnect the dimmer switch and check the resistance between the white-black wire (on dimmer connector attached to the car) and a good ground on the car body. Should be a short (~0 ohms).

If that's okay, then with the tail lights turned on, check the voltage on the green and white-green wires, should both be 12 V. Finally, short the white green wire to ground and the dash lights should come on full brightness. Let us know the results of these tests and we can go from there.

NOTE: colors are for 89+ cars, probably same for <89 models, but if the colors don't match don't proceed with tests above.

Ok, I just tried exactly what you told me to. Everything tested out as expected. When I shortedthe white-green wire to ground (w/ tail lights turned on), the climate control lights turned back on, BUT dashlights still blacked out, AND I blew the tail lights fuse.

I believed I had tried this method before and blew the tailights fuse.

-Climate control lights turned back on
-dash lights aren't
-tailight fuse blown:biglaugh:

 

[MKIIINA]

my fuses were fine, swapped out the dimmer from my buddy's car and bam dash lights. i has inspected the dimmer for signs of charing or broken contacts, nothing. bought a dimmer off another forums member and bam dash lights work

 

[shaeff]

so all of your dash lights turn off when you turn the exterior lights on? replace the dimmer rheostat, and be happy. if it's unplugged, the same thing will happen. if it's dead, it'll happen.

-shaeff

 

[aye mate]

so all of your dash lights turn off when you turn the exterior lights on? replace the dimmer rheostat, and be happy. if it's unplugged, the same thing will happen. if it's dead, it'll happen.

-shaeff

Werd. Smell the dimmer when you take it out also. My smelled burned and I replaced it and all my lights came back.

 

[LexingtonBlue]

Shaeff, I replaced it with 2 other ones and bam....no dash lights still. LOL

I'm watching one of those fog/cruise/dimmer switch panel on Ebay...will probably buy it and HOPE that the 4th is a charm...kekeke....unless somebody on here got an extra one that works. Right now, I'm using one of those "radio neon tube" lights, mounted between steering wheel and dashboard....it works as temp.

 

[3p141592654]

Interesting. Okay, all the lights you mentioned are in parallel. As I recall this all happened after you fried the cig lighter. I would start by unplugging the lighter connector and repeating the test (hopefully you have a stockpile of TAIL fuses!).

A possible scenario for this would be a short circuit between the G and G-W leads of the cig lighter itself (the lighter illumination circuit). Another possibility would be a short between those same wires but on the car side of the connector to the lighter. It is possible you overheated the insulation on the cig lighter loom when you shorted it and the G and G-W wires are touching each other now.

I would focus on the lighter since that was the event just prior to all your trouble.

 

[LexingtonBlue]

Yes, I will attack it hopefully tomorrow. And I did bought a whole new pack of 25 15A's. LOL!

I also remembered trying to light up the cig illum. and the astray light using a different 12V source, but it didnt' work.