Instrument cluster lights stay on

[FarmerDale]

Did a cab swap for my 87 V10. Had planned to use a new wiring harness, but the old one in Brownie appeared to be in good shape, so I moved that over. While I had the harnesses out I looked them over and spliced (solder and shrink wrap) in the places that had hard insulation, etc.

The problem I am having is:
Instrument cluster lights are on unless dimmer is all the way clockwise (this might have to do with the LEDs I put in. I assume a resistor should be installed to return dimming function.
Just last night I installed a bulb drivers side parking light and it lit up. What's most amazing about that is the light switch is removed!

I'm assuming these two issues are closely related, but would like a little direction as to where to look for what problem.

Thanks

[ray_mcavoy]

The parking light bulb lighting up even with the headlight switch removed sounds like your wiring harness has a short circuit between the parking light circuit and a constant feed.

You might want to double check your repairs to make sure you didn't accidentally cross a couple wires. In particular, look at the brown wire for the parking light circuit (circuit #9 on the factory wiring diagrams) and see if you can find anywhere it's accidentally hooked into a red or orange wire (those colors are commonly used for feeds that are hot all the time).

Also check over the plastic connectors (particularly the one on the headlight switch). Make sure it isn't melted or cracked and allowing a couple of terminals inside to touch together.

The instrument cluster light circuit receives power from the parking light circuit, routes it through the dimmer rheostat, and through another fuse before powering the bulbs. So if the parking light circuit is staying energized all the time that could explain the cluster lights staying on unless you turn the dimmer control all the way down.

[FarmerDale]

Thanks for the response, Ray. Will do as recommended and look through the front end of the truck. Hopefully it is obvious.

Dale

[FarmerDale]

The solution to my particular problem was found behind the light switch. The orange (hot for dome light) and brown (marker lamps) wires were fused together. Cut, solder, wrap and all is good. Now to get the temperature gauge to not read full hot and I will have made some real progress.