instrument lights brighten

[rocky raccoon]

This one has me stumped so far. Sometimes (not always) my dash lights go full bright and uncontrollable under the following conditions:

Headlights on high beam
Climate control defrost or air conditioning button pressed

When in that condition, all other interior and exterior lights are normal. Pressing "Economy" on climate control or switching off high beam headlight to normal driving headlight restores dash light operation to normal.

It is apparent that I have a difficult electrical short to find but I am hoping one of you have encountered this or a similar problem and have a solution in hand. If not I will keep looking and keep you-all informed.

[RadioTek]

There are known problems with the grounding of the instrument cluster. The recommended fix is to remove the cluster, clean up all ground points (circuit boards to metal back), and attach another ground lead from the back of the cluster to a good frame ground behind the dash.

Remember to put a detachable connector in the new ground lead (bullet or spade lugs). You will need to take the cluster back out at some point, and the 'reusable' connector will be handy.

Scott

[Kimolaoha]

Could it be the dimmer rheostat itself, as they are definitely failure-prone?

[rocky raccoon]

Thank you both. I will attack the problem starting from the least intrusive/expensive fix. I'll keep you posted.

I'll need a break in the action at work before I get started.

[rocky raccoon]

Found loose electrical connector making intermittent contact on climate control pushbutton unit. Reseated connector, inspected all other connectors and light bulbs.

Problem repaired. Thanks for responses.