[Guest]

About 3 days ago, my 1987 Turbo started doing wierdness...

As soon as the key goes to ON (whether the engine is runnign or not, and for the ENTIRE time the key is ON), 3 idiot light light up -- but they light up slightly dimmed (maybe 80% normal brightness):

- The Brake light (for the hand-brake)
- The Battery light (Charging system)
- The Tail Light light (for when a tail light is out).

Now here's the thing. The charging system is and was working perfectly. The hand-brake is obviously off, and the tail lights are fine.

Now the hand brake is an easy one to test... yup, it's down.
The charging system has been tested and is in fact fine.
The tail lights are all on and operational. I once had a loose connection in there (about 6 months ago) that would flash the light once in a while, but that's fixed, and there is nothign else wrong with them that I can find.

Essentially, these systems seem fine. One more detail: when I DO put the hand-brake on, the BRAKE light gets a bit brighter, which is how I twigged onto the fact that these 3 lights aren't on at full brightness....

My best guess is it's a probable short somewhere. I pulled the dash apart and cant find any worn or broken wires behind there anywhere... Even the dealership (on the phone) agreed it's a pretty strange combination of indicators to be going on...

So my question to you: What on earth could do this?? Where can I look for possible faults? I have tried tracing wiring diagrams, but because these systems seem basically unrelated, I can't figure out where the fault could be... COULD this be a short? If so, any ideas where? Could this be caused by the computer having a hairball on me?

Any ideas on what to try next?? I really can't afford to pay a shop hundreds of dollars to trace a short right now... And I'd really rather find the problem instead of say disconnecting the indicators =)

Any suggestions are greatly appreciated!

Thanks in advance (and sorry for the long post)

Dave

 

[Lord Mike]

Just so yah know my ebrake does the same thing...lights about 80% when its off then lights more when I pull it up. Happened when I had Sears put some new tires on for me. I however think mine relates to the ABS because my car dounds liek ABS kicks in whenever i brake...

Also my headlights don't work and a fuse constantly blows for my dash cluster and stuff. This all started happening when I put the car back on the road for the spring/summer a few weeks ago. Took it to a dealer they suspect its Headlight Retract Control Module which they said was full of water and corroded. Points being something totally unrelated fucks shit up. Good luck.

 

[Guest]

Hmm.. well I haven't actually done anythign new to the car in a while (brakes etc) and my headlights work great... If it were JUST one of these lights, I could probably work out the cause, but all 3?! =)

Thanks for the input though =)

 

[Yeahdoug]

check brake fluid and see if it low.

 

[halsupramk3]

I had this same sitution happen to me. Two different mechanics could not identify the problem. I looked at my wiring diagram in the wiring manual and all three of these lights have a common ground point and that ground eventually makes it up to the altenator. So i replaced the altenator and had the same problem.

Well the original altenator tested it had a bad diode which i thought was the problem but as a final last choice after some more testing i tested the new altenator and it had a bad diode too. Dammit.

So your diode is bad in your altenator and the current is flowing backwards. Diodes make current flow only one way. The current flows up the ground to the lights and grounds out at the other end. If you dont run your car for a while your battery will drain down which is the first thing i replaced for this problem. Test your altenator and i bet the diode is bad.

So replace your altenator.

Hal
90T

 

[SupraMikeCT]

I had this same sitution happen to me. Two different mechanics could not identify the problem. I looked at my wiring diagram in the wiring manual and all three of these lights have a common ground point and that ground eventually makes it up to the altenator. So i replaced the altenator and had the same problem.

Well the original altenator tested it had a bad diode which i thought was the problem but as a final last choice after some more testing i tested the new altenator and it had a bad diode too. Dammit.

So your diode is bad in your altenator and the current is flowing backwards. Diodes make current flow only one way. The current flows up the ground to the lights and grounds out at the other end. If you dont run your car for a while your battery will drain down which is the first thing i replaced for this problem. Test your altenator and i bet the diode is bad.

So replace your altenator.

Hal
90T

^ AGREED, it's a problem inside the alternator, probably a shorted diode on the rectifier assy. inside the alt. allowing a back feed. Dis-connect the 2 wire plug to the back of the alt to see that the problem with the warning lights goes away.
~ mike

 

[Guest]

Oh wow, that sucks! =)

Thanks for the tip -- I'll try testing that today and see if the alt is the problem.

Oh and tghe brake fluid is topped up....

 

[halsupramk3]

By the way i have heard from an old post copied below that the 93 mr2 altenator "with power steering" will work with our cars and it is a 100 amp altenotor instead of 90 amps. I do not know if you have to change out any fusable links or not or how that would effect any electronics other than giving the car more amps for sparks.

The post i read is below:

You can get a 100amp alternator from a '93 MR-2 Turbo *WITH* power steering. The only thing you have
to do is drill out the hole on the battery cable as the stud it bolts to is a little thicker than the
one on the MKIII alternator.

HTH,

Dave 92TTOP
Chandler, AZ
www.geocities.com/suprattop
www.azsupras.com

i would think a 100 amp alt. would be better.

Any ideas?

 

[AGlobalThreat]

Don't u guys check the FAQ's first??? :dunno:

http://www.supraforums.com/forum/showthread.php?t=115331

 

[Guest]

I thank you all for your help! It died on the way out to my dad's place (cause he's got tools and I don't, living in an apartment and all), just died. The stereo went first (just turned off, the antenna moving up and down), then the heater blower stopped, and then those same 3 idiot lights began to dim. Then, as I was waiting at the stop light... it just stalled.

There was NO juice left in the battery.

Anyhow I had it towed the rest of the way there (HOORAY for the auto club!) and phoned around for a new/rebuilt alternator, after the tow truck guy tested the charging system and determined there was like zero power being supplied by the old alt.

Found a rebuilt one for $216 (canadian) which is a lot better than the $325+ they wanted at the dealer for a rebuilt one.. I got it home and much to my surprise had it swapped out and the new one installed and ready to go in about an hour!

We tested it out when we started it up again (during all this time, the battery was on a charger), and yep! 14.2 volts coming off the alt. Hooray! :bigthumb:

The old alt is pooched... You guys were right =)

Thanks again!