HELP - Wiring Problem!!!!

[69C10@16]

First let me kind of introduce myself...
I am 16. I live in Missouri (a.k.a. misery). I am halfway experienced with trucks. I bought the best ever first truck a 16 year old could hope for, a 69 C10 with the original 307 rebuilt and under the hood and a turbo hydramatic tranny rebuilt same time. Oh Yeah.

Now my problem.

When I turn the headlights on, the dash lights do not work. I have checked bulbs, they are all in working condition. Also when the headlights come on, My Right turn signal activates BOTH turn signals and my left turn signal does the same but it doesnt flash them as the right does still flash them. My Gas Gauge dont work (ever so I doubt it is a part of the problem). All fuses are great and this is only an issue when the headlights are ON. If I mess with the harness connection at the back of the gauges, the lights will come on and my gas gauge will go to WELL over full but I still have the wierd problem and my turn signal indicators always light in this case. When i let go of the harness connection it goes back to the other way. Where nothing works. The generator light seems to be the ONLY thing working properly in this dash. My temp light stays on no matter what (which I assume is because some idiot before me cut the wire to the sensor).The headlight switch is brand new from classicparts.com as of yeterday. I do not know if this was a problem with the old one or not. I never tested it. I could drop the old one back in but it would take me a while becasue my mechanic is supposed to be calling me any day to replace the lower ball joints and the upper control arm shaft for me so I dont want to rip anything out. In the meantime, are there any ideas as to what could cause this WEIRD problem.

I'm sorry this is so long and complicated which is because Im horrible at explaining things verbally and in writing.

Thanks,
Newton

[sb69chevy]

Don't know the answer to your question, but to the board from Springfield! I tend to agree w/ you on the "misery" part...

[dwaite72lnghrn]

I would start checking for bad grounds. Temporary check take a jumper cable from the battery negative to the body. The core support or the cab(near the master cylinder) Then try your lights. Most of these trucks have bad grounds(corrosion) after 30-40 years.

[panhandler62]

I think I would start by seeing if the symptoms are different or non-existant with the old switch. If that doesn't tell you anything then move on to the suggestion in the message above this one.

Also check the connector and the printed circuit on the back of the cluster as these can take a beating after 40 years also.

Ps.. if your thread vanishes it means that the mod incharge of this section has moved it. You will probably be able to find in in the Electrical section.

[Andy4639]

Take a look at the back side of your dash. The circuit board sheet that runs the whole back side should have a ground wire ran to fromm the dash itself. If it's not grounded then you will have all kinds of issue's with the dash lights.

[centsless]

I agree with Andy. Take a jumper wire from the back of the dash cluster to the dash itself and see if it all works. Hope that helps, and welcome from Maryland!!

[hyarbour]

Is it possible to push the intrument cluster plug in upside down? That could make eveything operate kinda fubar, if it didn't just burst into flames

[Peter82]

here is a wiring diragram. check the wires and good luck.

[centsless]

Originally Posted by hyarbour

Is it possible to push the intrument cluster plug in upside down? That could make eveything operate kinda fubar, if it didn't just burst into flames

The plug is indexed ( has an ear on one side ) so it cannot be plugged in upside down.

[69C10@16]

I have tried all kinds of stuff. Re grounding circuit sheet, grounding each individual light, disconnecting circuit sheet, disconnecting headlight switch, switching the flashers around. I am totally out of ideas.

[shifty]

tried a new circuit sheet?

[69C10@16]

The circuit sheet looks like it's not the original. I haven't had time quite yet to use a continuity tester to make sure all of the traces go all the way through but I plan on it soon.

[Huck]

You mentioned symptom change when messing with a connector---my guess is that you have multiple issues. I would first remove the dash cluster----you will be able to sell things much better. Then start tracing the wiring as you refer to the attached diagram. Look for broken or spliced wiring br a previous owner. Make sure these are fixed correctly (according to the diagram). Pay particular attention to the connector as it should not change symptoms if wiggled. Any short in the steering column will drive you nuts too. You just have to kind of trace one wire after another to work you way to the problem. Takes time but at least you are not dealing with a computerized vehicle. The fuel gage issue is typically a broken or grounded wire that runs from the tank sending unit across the drivers side floor in the gully next to the rocker panel. PS---never had a faulty light switch so check and re-check the wiring & grounds before throwing parts at it. Good luck~~Huck

[69C10@16]

To all those who said it was a bad ground........

After taking off my tailamp covers a couple of weeks ago I noticed that the moron that primered the thing had primered behind them on the, for lack of knowing what its called, socket plate too. I thought nothing of it as my lights were still working then, flawlessly. I got so frustrated with this junk that I needed something **BRAINLESS** to do for a while so I took the socket plate out to clean it so my lights would be brighter if it reflected off bright shiny metal and low and behold they primered between the socket plate and the bed itself!!!! Ground, what ground. That aint no ground!!!! So a corded drill and a wire brush and a few hours later, LIGHTS. (That work right) With the exception of the Left, Front Parking Lamp and the Right Rear Turn/Brake Lamp. I am hoping that when I put the turn/brake assembly back together I lost a connection that will be simple to fix. On the front I hope like h3!! it is just that ONE of the two elements burned out. I can hope no matter how unlikely it is. While I was wiring I even added some relays I had laying around and relayed my headlights. Folks, it aint no myth that it makes the poor things brighter I can tell you that. Now, on to the body. My Rocker Panels are practically nonexistent. There is a hole the size of a bouncers fist in the driver side cab floor, and a couple of dents and dings. The bed must be rebuilt as far as the cross sills go because they are a F.U.B.A.R.'ed. Anyways, I guess I should start a thread on my build. It won't get updated too often because, as I said before, I am 16 and its football season. My boss knew I was gone during football so I have ZERO income. Which sux. So thats why it wont get updated much. Nothing will be happening. But I'd like to get some pictures posted. I still haven't decided, restoration to FACTORY (exc. stereo, it must NOT be fact.) or custom rod???? What to do....... anyways, Ill post the thread link here when I get it up with pics. Thanks for all the help and sorry this last post is so RETARDEDLY long.

Newton

[krue]

Welcome to the board from south Mississippi! My first truck was a 69. But that was a long time ago. Hang in there, you have plenty of time to finish the truck, so enjoy playing ball for a while.