Only front parking lights work. Need help.

[White70C20]

Hello all,
I'm having an electrical issue.
Only the front parking lights and the side marker lights work on my '71 C10. I have checked all the fuses with a test light (everything but the panel lights fuse is getting power), replaced all the bulbs (headlights, taillights, market lights), and I replaced the headlight switch and turn signal relay. I just wanted to rule out any of them being burnt out being a cause.
I did notice that there are two wires running out of the area of the fuse box marked "fuel gauge". Also, there are two push knobs, a toggle switch, and a dial type knob (all aftermarket) on the instrument panel. I've included pictures of everything.

I'm unsure of how to go about getting the lights to work. I've tried everything I can think of. Any and all suggestions will be appreciated.
Thanks!

[Longhornss]

I would start with a multi meter and check and make sure you are getting good 12v going into the switch. Should be a heavy red wire going into the switch. Some of the older....if not all GM vehicles, the park light was its own fuse and then the power for the headlight was "direct to the batterie" there is a built in circuit breaker in the headlamp switch to protect the wiring no fuse for headlights.

[White70C20]

Which switch are you wanting me to check?

[White70C20]

Also, I forgot to mention that the windshild wipers don't work either. Basically, the truck runs and that's about it.

[Longhornss]

Originally Posted by White70C20

Also, I forgot to mention that the windshild wipers don't work either. Basically, the truck runs and that's about it.

First thing to check is if the wiper is getting power with the key on. The wire at the motor should be either yellow or white.
Posted via Mobile Device

[White70C20]

Ok. I'll check tomorrow afternoon. Truck sits outside, so it's kind of hard to work on it in the evening.

[chevytruckluver]

It sounds like you may have more than one problem, but I would try making some ground wires first. Make one or buy a short battery cable with eyes on each end, that goes from somewhere on the engine and take it to the frame. Make another that goes from the engine to the cab and another that goes from the engine to the core support.
After you are sure that you have these start with one problem at a time and go from there.
I would take out all of the non factory pieces if you don't know their purpose.
I would also check the dimmer switch.

[White70C20]

Originally Posted by chevytruckluver

It sounds like you may have more than one problem, but I would try making some ground wires first. Make one or buy a short battery cable with eyes on each end, that goes from somewhere on the engine and take it to the frame. Make another that goes from the engine to the cab and another that goes from the engine to the core support.
After you are sure that you have these start with one problem at a time and go from there.
I would take out all of the non factory pieces if you don't know their purpose.
I would also check the dimmer switch.

My friend owned the truck since 1997. To my knowledge, he never did any electrical work to the truck. He couldn't have driven it for several years with no lights. I'm just trying to figure out why a truck that survived quite a while with the grounds it has, and had functioning lights for many of those years, needs new ground straps put on now.
I'll be the first to admit that I don't know a whole lot about electricity, but I dp think it about has to be something that is already in/on the truck.
I have attached a picture of what is at the ends of the two wires coming out of the fuel gauge area of the fuse block. I can't just remove them because one of them branches off and goes under the floor matting.

I'm not trying to be rude, I really do appreciate the ideas and suggestions.

[cdowns]

I like the way you spent the time and cleaned up the fuse box

[chevytruckluver]

Originally Posted by White70C20

My friend owned the truck since 1997. To my knowledge, he never did any electrical work to the truck. He couldn't have driven it for several years with no lights. I'm just trying to figure out why a truck that survived quite a while with the grounds it has, and had functioning lights for many of those years, needs new ground straps put on now.
I'll be the first to admit that I don't know a whole lot about electricity, but I dp think it about has to be something that is already in/on the truck.
I have attached a picture of what is at the ends of the two wires coming out of the fuel gauge area of the fuse block. I can't just remove them because one of them branches off and goes under the floor matting.

I'm not trying to be rude, I really do appreciate the ideas and suggestions.

Attachment 1417661

Ok, no problem. I was not saying to strip every extra wire out and start over, I was really saying if you don't know the purpose of something that was added over the last 45 plus years it may be a good idea to disconnect it. (you can always put it back if its not causing a problem)
The fact that you have several items not working and no fuses are blowing is a possible indication that you have grounding issues.
Anyway whether or not the previous owner added or not any wiring or switches or grounds you should have a level starting point. Checking grounds is fundamental in checking for electrical problems. Then using the color electrical drawings found here http://67-72chevytrucks.com/vboard/s...d.php?t=185856 you can run down each problem one at a time.
I would make a list of each problem you have and start marking them off one at a time.
good luck

[VetteVet]

Yeah Cliff I noticed that too. That is the best candidate for a new wiring harness and fuse panel I've seen in awhile. I see a lot of corrosion on the fuse holders that could still be cleaned. There are several things that look a bit shaky. I don't know what that is hanging from the wire unless it's the dimmer switch.
Now we've got a new thread in this section which is against the forum rules and it creates confusion.

[White70C20]

OK, how is this against forum rules?
Fine! If the moderators agree with this guy then go ahead and delete this thread. I don't have the time to be cleaning up every single wire on this truck anyway.

[cdowns]

Originally Posted by White70C20

OK, how is this against forum rules?
Fine! If the moderators agree with this guy then go ahead and delete this thread. I don't have the time to be cleaning up every single wire on this truck anyway.

ok then make do with the parking lights

[VetteVet]

.............

Originally Posted by White70C20

OK, how is this against forum rules?
Fine! If the moderators agree with this guy then go ahead and delete this thread. I don't have the time to be cleaning up every single wire on this truck anyway.

http://67-72chevytrucks.com/vboard/a...t.php?f=64&a=9

Read them all especially the no. XIV
You can save yourself several thousand dollars by using the advice you'll get on here, but it takes some effort, a lot of effort. Just PM a moderator and ask them to merge this thread with the one on the electrical forum.

[White70C20]

Originally Posted by VetteVet

.............



http://67-72chevytrucks.com/vboard/a...t.php?f=64&a=9

Read them all especially the no. XIV
You can save yourself several thousand dollars by using the advice you'll get on here, but it takes some effort, a lot of effort. Just PM a moderator and ask them to merge this thread with the one on the electrical forum.

Ok. I'm all about the effort, (A LOT OF EFFORT) after all, that's why I decided to go back to school to restore old cars. I have lots of time in the evenings to work on this truck. What I don't have is a lot of money. I can't afford a new wiring harness, so I need to make do with what I have.
Just please guys, do me a favor. Keep your suggestions cheap! The main reason I have this truck is because it was given to me.

Thanks!

[cdowns]

cheap is a piece of sandpaper and elbow grease cleaning but you dont seem to want to go thru that effort

maybe you'd b better off hiring somebody to clean and straighten your wires out for you(should only cost a thousand or so to have somebody do your dirty work)

[cdowns]

Originally Posted by White70C20

OK, how is this against forum rules?
Fine! If the moderators agree with this guy then go ahead and delete this thread. I don't have the time to be cleaning up every single wire on this truck anyway.

that is why I suggested you hire an electrician to work where you cant or don't want to do it

[White70C20]

Originally Posted by cdowns

that is why I suggested you hire an electrician to work where you cant or don't want to do it

I may end up having to do that. I know a mechanic who knows these trucks inside and out. He's had several of them over the last 35-40 years.
His shop is twenty miles away. I hope I can make it there without any lights. Ha Ha.

[Jurassic-1]

Did you test the headlamp plug with the lights on? You may just have a bad dimmer switch. Sometimes they get wet on the floor and get rusty connections.