Guy

Hello,

Searched for this and found other people with the same problem but no solutions.

My rheostat is shot s my interior light wires are bridged for now

Lights on the cluster worked fine at first but now are illuminated all the time, regardless of the headlight switch position. Seems like an odd problem.

Any ideas?

Thanks, as always!

Guy

Alan

There is no problem here...

They are supposed to be always on with the ignition, they go to the dimmer position based on the rheostat only when the lights are on.

So quite normal for the condition you now have...

Some pod switches are always illuminated also - like the main light switch... so you can find it in the dark...

Alan

Guy

Alan

Very interesting. So once I reinstall the rheostat, they will come on with headlights only?

Thanks
Guy

Alan

No - what I said

They will always be on with the ignition (they always were) - if you drive into a tunnel with your lights off - you will be able to see the instruments. They go to the level set by the rheostat only when the lights are on - so they most likely will get dimmer when you turn the lights on. This makes sense if you think it through, though it sounds counter-intuitive.

Alan

Guy

Ahh......thanks Alan, I am a bit challenged

Randy V

May I also suggest that you

If you don't have one, then get one.

See the FAQ thread for a source.

Guy

Thanks, Randy.

I have one and read it.
I have the WSM as well and read it.

Everyone misses the obvious now and again, thanks for your understanding and patience.

Guy

Just a brief follow up. Installed a good rheostat today and got the following results:

Ignition on, headlights off:

Cluster lights on and rheostat works, HVAC and clock light on

Ignition on, Headlights on

Cluster lights on and rheostat works, HVAC and clock light on, both ashtray lights light. Hazard switch, odo reset, defroster light and rear wiper switches light

So my cluster lights are on and rheostat dims them regardless of headlight switch position.

Alan

Well that made me go take another look. Yes it seems the early clusters are different and you are correct its via the rheostat all the time fed from the ignition circuit (on all the time when running), the reasoning is the same though: so you always have some cluster illumination.

However in '85 - '88 this was switched to just illuminated variably via the rheostat when the lights are on (in either marker/headlight position). So these 4 years are a bit of an anomaly for under what conditions they are illuminated...

For 89-95 it is exactly as I described before: Illumination always on with ignition on, bright if the lights are off and variable via the rheostat if the lights are on. Actually the brightness with the lights off is controlled by a photocell in the top of the guage face so in the darkness these will auto dim a little, while in full daylight they will be full brightness (you can test this in the dark with a small flashlight).

Well I learned something new here.

Alan

Guy

Alan,

That makes sense. Thanks for all the help and guidance. As you can see from my signature, I "lurk" far more than I post and as such I make extensive use of the search function. I like to follow up on my own posts to help others get answers in the future.

Thanks!
Guy