M1028 light problems

[Thompsona3]

So I have a 1987 m1028 and I noticed my tail lights both brake and running lights where not working along with my turn signals and running lights and my dash lights. I already cleaned a ground for my dash lights but that did nothing. I thought I read that the turn signal switch runs power to these. Can anyone confirm that? If that's not true does anyone have any idea on what could be going on. All my fuses are good and my headlights work so it's not the service lights.

 

[Thompsona3]

Just cleaned my tail light ground as well. Still nothing working

 

[cpf240]

Does the horn work? I know it is a simple thing, but is the BO light switch in the 'Service" position? Otherwise, all that you mentioned, in addition to the horn and headlights, will not work...

 

[cucvrus]

Check the 30 amp fuse on the right side midway up the fuse box. They are known for overheating and having a poor contact.

 

[Thompsona3]

All fuses are good horn has never been hooked up since Iv owned it

 

[cpf240]

And the position of the Service Lights switch?

 

[Thompsona3]

Service light is on and other one is in the center position. Would it matter though because I still have headlights so that should eliminate the service light switch.

 

[cpf240]

Sounds like it is not the service light switch then. As mentioned before, check the headlight fuse area of the fuse box. Even though the fuse looks / tests good, the connection inside the fuse box may have corroded, or even melted, so that it no longer makes contact.

 

[Thompsona3]

So just found out the 30 amp fuse in the fuse box is missing a connector. Working on separating the box but it's being a pain. I'm hoping I can replace the connector and all will be well. I feel like this is bit of a long shot though because my headlights still work.

 

[cucvrus]

??? I am in doubt but it may be the issue. Who knows what one else was doing to the harness. I have seen it all on these vehicle.

 

[Thompsona3]

Does anyone know if there is a single hot wire for multiple fuses? Is it possible?

 

[cucvrus]

Yes that one wire on the back of the fuse panel serve 2 of the fuse banks on that bus bar. I think the brake lights and the main lighting wire. Both them fuses are affected by that single hot wire on the rear of the fuse block. I know what I am saying just having trouble writing it. I hope that helps.

 

[Thompsona3]

Thanks that does I think there is a possibility that it is my turn signal switch. Going to try and replace that.

 

[MarcusOReallyus]

Before yuou replace it try jumpering across it to replicate the correct function. If that cures the problem, then replace the switch.

Wiring diagrams are free for downloading here on the site.

 

[suzukovich]

I have a 1028 in the shop now. Need to locate some things Truck is missing the B/O service drive switch. Were can I find one. Thinking is why brake lights are not working. Everything works but brake lights. I also need to source lug nuts. and confirm DOT 5 for brake fluid.

Thanks

 

[cucvrus]

Check the stop lamp fuse and the tension on the fuse holder to the fuse. And also use a test lamp and check if you have power going to the brake lamp switch. Easy switch to replace no tools required and less then $10. Autozone Part # DR496. Good Luck. Report back. DOT 5 is the correct brake fluid from new. Lug nuts are just standard 9/16" fine thread lug nuts. Available at any auto parts store.