Brake/marker lights don't work

[walkerbzz11]

Ive been doing some various jobs on my M1008 lately and all of a sudden I noticed my brake lights don't work on either side. No running lights or marker lights on the driver's side rear. Markers and running lights work on the passenger side but not super bright like the reverse lights do. Both reverse lights burn bright and everything on the front end is working. I've went around the truck checking all the grounds that I know of and shined them up some. The sockets on the driver's side rear show 8 volts for some reason. The passenger side, which works except for the brake light, shows 10 volts. Fuses and bulbs are all good. I've had the dash and instrument cluster out for some other work but I have no idea what I've done to cause this. Any ideas? Thanks.

 

[cucvrus]

Check the fuse area on the right side midway up is a 30 amp that gets heated up. That power leg serves the brake lights also. Common issue.

 

[walkerbzz11]

Check the fuse area on the right side midway up is a 30 amp that gets heated up. That power leg serves the brake lights also. Common issue.

Awesome. Hope so.

 

[walkerbzz11]

Awesome. Hope so.

I've rechecked. They're all good.

 

[cucvrus]

I've rechecked. They're all good.

They will appear good. You need to probe them inserts and fuses with a test light.

 

[walkerbzz11]

They will appear good. You need to probe them inserts and fuses with a test light.

If you mean checking them with a multimeter, I've done that for resistance and they all show good. Now I do not have the proper fuses in some of the places in the fuse box and some look old. I'm gonna get that right I guess. Ye haw! Gotta love it. It's raining too! But I will win!

 

[ehuppert]

I had an issue on right rear lights. There's a ground wire under the light housing that the metal attachment point was gone! It's been a bit, but believe theres ground points/wire for both rear light housings

 

[walkerbzz11]

I had an issue on right rear lights. There's a ground wire under the light housing that the metal attachment point was gone! It's been a bit, but believe theres ground points/wire for both rear light housings

Yea. Mine where pretty rough. I've redone all of em now. Thanks

 

[Barrman]

You don’t need to just check the fuses for being good fuses. You need to verify power is getting to and from the fuse legs. The wire end pins inside the fuse panel melt into the plastic and no longer touch the fuses sometimes.

 

[walkerbzz11]

You don’t need to just check the fuses for being good fuses. You need to verify power is getting to and from the fuse legs. The wire end pins inside the fuse panel melt into the plastic and no longer touch the fuses sometimes.

Oh boy! How do you correct that?

 

[Barrman]

That is the worst case scenario. Using a finger nail file to clean the contacts and a dental pick to bend the pins closer together might be all you need to do if this is even your problem.

 

[ehuppert]

The running lights front and rear should be on same fuse. So if front is working the rear should also have power. Brakes are a seperate circuit. Sounds like a wiring or ground issue. Check the wire harness connector in the rear end and check voltages there.

You can also try hooking up a duplicate ground wire to bulb body with running lights on and see if brightness changes.

Resistance in either ground or power connections and or wires can cause issues.

 

[walkerbzz11]

The running lights front and rear should be on same fuse. So if front is working the rear should also have power. Brakes are a seperate circuit. Sounds like a wiring or ground issue. Check the wire harness connector in the rear end and check voltages there.

You can also try hooking up a duplicate ground wire to bulb body with running lights on and see if brightness changes.

Resistance in either ground or power connections and or wires can cause issues.

I went around freshening up ground connections all over the truck and had the instrument panel out doing other work. I also had some fuses that were not the proper ones for the circuit they were in so I corrected that. Replaced a headlight and light switch. I'm not sure what did it but I've got all lights working again. It's weird. I had 8 volts before and the bulbs wouldn't burn and after all this stuff I've done it's back to 11.8 so who knows. Thanks.

 

[walkerbzz11]

Does it matter what bulbs I use? Currently I have 1 2057 in one brake light and an 1157 in the other. I've also got a 168 in one marker light and a 194 in the other. 168 and 194s in my instrument cluster too I think. It's all working but what's right?

 

[Buck69]

Bulbs are cheap. I just replaced them all when going through mine. Any pigtails with a rough looking pin as well.
The only place I ran into mismatched bulbs was in the gauge cluster. It had a 24v bulb for the gen 2 light.