I'm a first-time poster and primarily a British car guy. Thanks in advance for any help you can provide. My old truck is showing some flaky electrical symptoms. I'm also ...

I'm a first-time poster and primarily a British car guy. Thanks in advance for any help you can provide.

My old truck is showing some flaky electrical symptoms. I'm also getting ready to install a fourth fuel pump (over 160K miles) to correct the fuel level sensor problem, and would appreciate any advice on a long-term fix.

First issue was that backlighting on headlamp/dimmer switch wasn't working. I pulled the switch, tested the lamp (good), and put the lamp back in. The backlighting would work only if I operated the rotary switch a few times. Also, the dimmer portion backlighting never worked. Decided to replace the switch - Backlighting on main portion of switch now works consistently, but dimmer still doesn't light. Both original and replacement switches work fine otherwise, by the way.

Second possibly related trouble - None of the backlighting on any of the left door switches works. The courtesy lamp on bottom door corner does. I've seen several drawings on the web, but not sure which are relevant. Don't see a fuse marking in the panel on left side of dash that looks obviously related.

I have searched forum and have seen similar issues, but not quite this. Any ideas?

Thanks,

Bruce

Hi Bruce

There is no fuse for the door switch lighting. You door switch lighting is one of two issues. Either the lights inside the switches are burned out, or they have a bad solder or cold solder connection. The only way to tell which of the two is the issue is to take the switches out and tear them apart. Very easy to fix either issue. If you don't want to tear them apart you can replace the switches with new ones. The issue on your headlamp switch is the dimmer rotary isn't lighted at all. In 2000-2006 they have never been light. You can solder a another light to the headlamp switch circuit board to make it light up though. The issue with the original headlamp switch was that where the light made a connection with the circuit board was weak. If you would have adjust the copper prongs to make a better connection it would have worked. The lights in the door switches are always leds. As far as all the other lights, radio, climate control, and speedo are all regular small light bulbs. 2003 and up the light bulbs inside the speedo are soldered into the circuit board. Previous to that they are twist turn light bulbs. Only in the speedo though. All the rest are soldered. I have fixed alot of these issues with trucks over the years. If GM would have started putting leds in everything a long time ago we wouldn't have these issues with the older trucks. Let me know if you need anything else. Happy to help.