Dash lights go out and gauges peg high?

[Whitefirstgen]

OK things are getting clearer as i work thru the issues. I previously posted about lights doing some crazy stuff. i fixed abs and brake lights, BUT i still have one more to go.....

Sometimes when i turn on the headlights, via the original head light switch, the lights come on, BUT the dash lights go out, speedo needle goes to zero, gauges peg high, turn signal arrows come on bright and stay lit. This does not happen every time but maybe 1 out of 5 times i run the truck. Also I just noticed tonight that i can bring the gauges back to life if i dim the dash lights by rotating the head light switch.

Is this just a bad head light switch? other thoughts?

thanks again
Mike

 

[hcole]

This sounds like a loose ground wire in the area of the dimmer switch or the ECM. When you turn up the dimmer switch, it calls for more current for the dash lights and overwhelms the ground connection and the connection has to find the ground somewhere so it makes the gauges erratic. Hope this helps.

 

[hcole]

Changed my mind , I think you should look for the bad ground connection on the instrument panel around the gauges. That, I would bet, is where the problem is at.

 

[Whitefirstgen]

Where would the ground be located? (For instrument cluster) any thoughts?

 

[Whitefirstgen]

update:

i cleaned the ground right off the battery (small wire) and i cleaned the main ground off the battery ( large wire). Neither looked real bad but no they are nice and clean.

I found a ground bar next to the steering column and it had two ground braided straps and couple smaller wires connected to it. those connections were bright and shiny and tight.

i could get the "fault" to come back to really cannot tell if i did anything. BUT i did find a HOT ignition lamp time delay relay. as the shop manual says it is taped to the main harness to the left of the steering wheel. I do not understand why that relay would be so HOT. The ignition switch was off and the only lights that were on were the interior dome lamp and the light under the hood. I closed everything up and will go back to ensure it cools off. I am not sure how that would cause my issue, but the wiring diagram shows the yellow wire from this relay going to the Headlamp Switch. Is is possible that one of those two has a short and is drawing down the ground?

I enjoy a challenge but this one is gonna get good!! any history or thoughts would be welcome....