4 Start Up Warning Lights

[TC KER]

I have a 1990 TC with the 3.0L engine.  The 4 lights to the left of the steering wheel above the headlight on/off knob on the dashboard that are supposed to light up momentarily when the car is started don't work anymore.  They're just off all the time.  Anyone have any suggestions to get these up and running again?

[Garnet & Gold]

Let's start with questions.  Have the lights ever been on?  Are the other lights on the dashboard on?  The headlight switch is also a rheostat and turning it clockwise to the stop will make the dash board lights dimmer.  Turning the switch counter clockwise will make the lights brighter and with a minor click on the counter clockwise turn will lock the lights in the brightest position.

[TC KER]

Hi, The lights have always worked until a couple weeks ago. I've had the car since 1993. All of the other lights you've asked about work.  The back up lights stopped working about 15 years ago; other than that all other lights are working.

[TC KER]

All of the other electrical parts are working; power windows, locks, seats, cruise control, top pull down motor, gas gauge, tachometer, speedometer, antenna, etc. The odometer stopped working about 15 years ago.

[Reaper1]

It's probably a bad solder joint where the ribbon comes down to the main PCB on the gauge cluster. Easy enough to fix.

[TC KER]

Thanks for the suggestion Reaper1.  I was waiting for it to cool down a bit since I don't have an A/C in my garage out here in the Coachella Valley.  But then I fixed the problem but still find this hard to believe.  I was sitting in the driver's seat and looked up at the mirror lights and the one on the passenger side was out.  I replaced that bulb and instantly those 4 warning lights went on and back to normal operations again.  Hopefully this is helpful to someone else or maybe it was just some sort of weird coincidence.

[Reaper1]

That's an odd coincidence. I'm glad the warning lights started working again, but the mirror light bulb shouldn't have anything to do with their operation.

[Hemi Dude]

After examining the wiring diagrams in the factory shop manual, I find no relationship between the mirror lamp and the instrument warning lamps. 

We might have to experiment and see if there could be some sort of ‘feedback’.

[TC KER]

So it was just a weird coincidence.  The mirror lights are still both working and the 4 warning lights went out again.

 

Reaper1 - What is "the main PCB" on the gauge cluster?

[Hemi Dude]

For us old guys, TC KER would you give the meaning of “PCB” please? I don’t see that abbreviation mentioned in the shop manual.

[TC KER]

Hi Hemi,

 

If you go up to Reaper1's posting on July 22 he used the term "PCB" to help me figure this out so I was asking him what it means.

[Reaper1]

Sorry...PCB = Printed Circuit Board

[Hemi Dude]

I see you live in Indio, a little less than 3 hours from my location in the desert.

when you say the warning lights go out, what do you see when they ‘don’t’ go out?

what I mean is, does the brake light come on when you apply the parking brake with the ignition key turned on to the run position?

we need a few more clues or descriptions of this situation.

[TC KER]

Hemi,

All four warning lights just don't light up at all in any situation.  They all went back on one day and now they are all not working whatsoever again. I backed out of the garage around the same time this happened and have the hard brake pedal thing going on. I didn't want to complicate the situation in this forum and figure that the first step in getting the brakes back up and running would be to start with repairing the warning lights.  I got a quote for a new ABS from Andy at TC Parts so I am happy I can get that if needed. I've read back through the years on this forum about the hard brake pedal thing and am studying how to put this puzzle together.  I've called some local auto shops out here in the Coachella Valley and haven't found anyone yet who works on these brakes which is no surprise.

 

Reaper1,

Thanks for the clarification.   

[TC KER]

It's been about 5 months so I felt I needed to give an update on this.  I didn't do any of the suggested fixes for this and may not do any because over the past few months the warning lights have been operating as they are designed to for around 90% of the time .  I haven't been able to put together any specific reason as to why around 10% of the time they are completely dark.  I'll give an update if anything helpful  arises from this.  

[JerryLG]

TC KER

It appears that the issue may very well be the left printed circuit board connector has a loose connector or a possible solder joint is bad. It appears that those warning lights and the distance sensor are on the same connector. Looking at a 1991 wiring diagram the park brake and brake warning light, the anti-lock warning, the low oil, check engine, temperature sensor, and distance sensor are all on the left printed circuit board connector (RED). You may want to check that connector to the dash panel whenever you get time to do so. 

[TC KER]

Thank you JerryLG.  Any chance you have a picture pointing out the connector you are mentioning. If not, I know Hemi does since when I met with him a couple years ago he brought some dashboard parts.................

[JerryLG]

TC KER,

I do not have any photos, as I was just looking at the '91 wiring diagram. It appears there is a flexible cable running from those lights over to the main printed circuit board (PCB) mentioned in the earlier posts. The connector is designated as being red and plugs into the left side back of the circuit board. There is another cable marked as gray on the electrical diagram that plugs into the circuit board on the right back side. Hopefully, another member will have some pictures if they have torn into the instrument cluster at some time in the past. 

[Hemi Dude]

I am working on a reply, "Stand by".

[TC KER]

Thank you for the pictures Hemi.........

[TC KER]

UPDATE: I took the instrument panel out of the dashboard.  Before I took all the wiring off the instrument panel I decided to twist the electrical green ribbon in different positions to see if I could activate the lights when I turned the ignition on.  It worked so I taped the green ribbon wire to the instrument panel in the position that it was working and all has been working like it was designed to do.  The original tape that held the ribbon to the instrument panel was no good so I replaced it.  There is probably some sort of loose connection but it works great.

[Hemi Dude]

Glad it's working for you now.