Hi guys.

Here is one that has me stumped. I swapped out my old hacked up dash gauge harness out of my 70 Chevelle with guages. The replacment harnesss is specific for this application. It is a refurbished and cheked original harness in excellent condition. After installation i have actually 2 problems.
1. When I turn on my headlights both turn siganl lights on the dash come on. They adjust in illumination with the dimmer. When I activate the turn indicator lever the flashers alternate back and forth. All grounds are tight and clean. The function of the headlights and turn indicators on the outside of the car are normal. The other thing I noticed was there is no high beam indicator light function. I think the harness is back feeding somehow. The printed circuit is new purchased from G/U. I checked the pinning sequence on the PCB connector and verified all is correct. I have swapped out the light switch and get the same results.

2. The fuel gauge is not working. I confirmed power getting to it through the PC. The gauge worked fine with the old harness.

I hope someone can help me out with this.

Thanks in advance.

Gary
70 SS Chevelle
Newcastle, Ont.
Canada

When I did mine it was a weak ground on my core support, one bad ground can lead to lots of problems. Your light switch might be bad also.?
Someone else will chime in your thread soon.

Gary, I'm having the exact same problem on my 67 chevelle, could you please e-mail me
and let me know what you find out. pblair@mcwprinting.com

Hey Gary, when the one guy said something about it having good grounding I went out to the car and took a piece of wire and grounded
the instrument panel to the dash and it worked, I was having the exact same problem you are. I had my dash power coated I guess that's why it had no ground. I guess I'll just use a piece of wire to ground it, if there's a different way please let me know.
pblair@mcwprinting.com

This may sound nuts, but when I grounded the core support directly from the neg batt terminal, the engine ran MUCH better.... weird... and the light problems I was having went away- not weird at all.

I too had paid attention to ground straps and thought it was pretty settled, but for some reason the core support needed a very direct connection. It was already grounded thru the fender attachment points, and the body was well grounded, with the engine feeding via several ground straps (the neg cable went directly to the engine block).

Just goes to show that even when you know how important grounds are and have taken steps, you might still want to check anyway.

Eric

Gary, also check your speedometer cable, that acts as a ground.
let me know what you find out. pblair@mcwprinting.com

Most wiring diagrams I've seen show a direct wire from the NEG battery terminal to a ground screw on the core support. This ground is also for the headlights, etc. These old electrical systems are fairly simple compared to newer cars but can still give us fits.

Well guys it's all fixed. All I can say is GROUND GROUND GROUND and then GROUND MORE.
It turns out the ground's I connected were fine. However there was a break in the ground between the dash and the battery. What I forgot was the car was recently painted and the body man who reassembled the car didn't clean the grounding points down to bare metal. This was discovered of course after I ran a new ground line from the core to a bus I installed in the dash area where I ran ground wires from the cluster and headlamp switch to complete the circuit. It worked then I just happened to look at the passenger fender and noticed it looked a little shiny to make a good connection. Sure enough I checked for continuity to the dash area and there was nothing. Sanded it down, reconected and life is good again.

I want to thank everyone for their ideas and support and I hope I may help someone here someday with their issues.

Now I need to work on timing and carburation. Anyone want to help?

Thanks
Gary Annis
Newcastle, Ont.
Canada