Very dim dash lights in my '95 Cutlass Supreme convertible

[Human]

I don't drive my '95 Cutlass Supreme convertible much at night--and now that the weather has gotten cold, I'm not driving it much at all. But when I do drive it at night, I notice the dash lights are ridiculously dim, just barely bright enough to let me know they're on. There don't appear to be any burned out lights; they're just not all that bright. While I may be more than a little spoiled by the dash lights on my 2011 Impala, I do feel the ones on the Cutlass should be brighter. My '95 Aurora's dash lights are not all that bright either, but they are noticeably brighter than these. 

Any suggestions?

Edited November 12, 2018 by Human

[Schurkey]

1.  Verify proper system voltage.  Engine running, alternator should output ~14.2 volts.

2.  Verify proper lighting voltage.  Engine running, voltage at the fuse that protects the dash lights should be at least 13 volts, preferably more.

3.  Spin the rheostat at the headlight switch to turn the lights up to full brightness.

4.  Verify proper lighting voltage at the bulb sockets.  THIS will be a pain in the ass.

Edited November 12, 2018 by Schurkey

[oldmangrimes]

I had a similar problem with my 95 convertible.   I thought I had a bulb burned out in one section of the dash, when I took out the cluster I realized that I had corroded/damaged contacts on many of the bulb sockets and multiple bulbs out.    I cleaned up the bulb contact areas, applied fresh solder to a couple of them that were obviously pitted and not making contact with the bulb, and replaced with all new bulbs (not LEDs).   HUGE difference, I realized that I'd probably had a couple bulbs out for all the years that I'd owned the car and never realized how bright the cluster should actually be.

It was a pain to remove the cluster, I actually ended up cutting off some plastic in a couple places to make it come out and go back in easier.   But before you go through through that hassle, do the quick voltage checks that Shurkey recommended above, it may be an alternator issue and often dim dash lights are your first clue.   

Oh, and don't be too embarrassed if you hadn't realized your dimmer switch was just not turned all the way up.    I've had that happen to me before.    

[Human]

So I drove the convertible this afternoon and didn't get home until after dark. Sitting in rush hour traffic, I had some time to observe the dash lights. The first thing I noticed is they would noticeably dim while I was sitting at a stop light but then brighten up a little bit once I got back under way but would dim down again at the next red light. While sitting at another long light I ran the dimmer thumb wheel up and down rapidly for a few seconds and the dash lights got a bit brighter so when I got home, I grabbed my can of CRC Electrical Contact Cleaner and spritzed it in around the little thumb wheel. The result was a noticeably brighter instrument cluster. I can't say that this represents a definitive cure or that it will even stay bright but it's a step in the right direction.

[GabsOlds]

Good for you. 

[Human]

Thanks. I'd still like to figure out what's causing the dash lights to spontaneously dim and brighten like that. 

[Imp558]

That should be the same switch assembly as the Regal from 95-96, why don't you just pop another switch assembly from the wrecking yard in and see what happens?  

Worst case scenario is you end up with a spare headlight switch. 

[Human]

Good idea. I'll keep an eye out for one. The trick will be finding a switch cluster that also has a fog light switch.

9 hours ago, Imp558 said:

That should be the same switch assembly as the Regal from 95-96, why don't you just pop another switch assembly from the wrecking yard in and see what happens?  

Worst case scenario is you end up with a spare headlight switch. 

 

Edited November 22, 2018 by Human

[Imp558]

If memory serves me those things are all just clipped into the assembly, you should be able to keep your bezel portion and fog light switch.

[Schurkey]

 

On 11/21/2018 at 11:44 AM, Human said:

Thanks. I'd still like to figure out what's causing the dash lights to spontaneously dim and brighten like that. 

Discharged/defective battery?

Alternator faulty or undersized (excess electrical load)?

Alternator regulator faulty?

Excess voltage drop in the charging system wire harness?

Low idle speed?

Incorrect alternator-crankshaft pulley ratio?

 

A proper ON-THE-CAR testing of the entire starting/charging/battery "power team" is MUCH better than popping the alternator off and having some parts-counter flunky put it on an Off-the-car "test bench".

 

[Human]

On 11/23/2018 at 12:15 AM, Schurkey said:

 

Discharged/defective battery?

Alternator faulty or undersized (excess electrical load)?

Alternator regulator faulty?

Excess voltage drop in the charging system wire harness?

Low idle speed?

Incorrect alternator-crankshaft pulley ratio?

 

A proper ON-THE-CAR testing of the entire starting/charging/battery "power team" is MUCH better than popping the alternator off and having some parts-counter flunky put it on an Off-the-car "test bench".

 

You're absolutely right. It's always better to test things like that as a system.