Couple of Electrical Faux Pas

[Dave K.]

Started the electrical testing on my 66 roadster body off project. All new harnesses and mostly refurbished components. Installed a 30 amp fusible link across the cutoff switch at the battery positive terminal. Everything works except the right turn signal and panel lights. When turn signal switch turned to right, horn blows. I suspect an incorrectly installed wire at the steering column harness plug. Had this apart to disassemble the column. Turned rheostat on the light switch both ways, turned on headlights but still no cluster or dash lights. Installed a new 4 amp fuse but to no avail. Clock, radio, blower motor all work but no lights. Could this still be a faulty ground and if so where? Since I have clock etc., I thought they used the same ground as cluster lights. High beam light works and left turn signal and light works.

Regards,
Dave Kitch
33108

[terry plata]

Re: Couple of Electrical Faux Pas

Dave, Could be ground problem, but first confirm plus 12 volts at the bulb sockets. I have seen the rheostat (dimmer) built into the headlight switch bad. The resistor wire is rivited to the ceramic disk and corrosion and vibration can destroy the electrical connection. Poof, no lights. Good luck. Sounds like you are on the right track with the horn/turn signal glitch. Terry

[John H.]

Re: Couple of Electrical Faux Pas

Dave -

The clock and cluster are grounded with the radio, at the radio connector pigtail (also grounds all the rear lights, fuel sender, etc.). Sounds like you have a couple of wires in the wrong cavity in the turn signal harness connector, and I'd verify continuity/function of the rheostat on the headlight switch.

[Dave K.]

Re: Couple of Electrical Faux Pas

John,

Why couldn't the cluster ground wire at the top of the cluster be off? Even though the cluster is grounded with the radio and clock the wire clip could be off or loose resulting in a complete loss of lights. Cluster, radio and clock lights all don't light. I intend to check cluster ground and power at one of the cluster lights.

Regards,
Dave K.

[John H.]

Re: Couple of Electrical Faux Pas

Dave -

If the cluster ground wire is off, you also won't have any wipers, lighter, directional indicator lights, or high beam indicator light (the headlight and parking brake warning lights aren't grounded to the cluster). If those are all working, the cluster is grounded.

[Dave K.]

Re: Couple of Electrical Faux Pas

John,

I stand corrected. You are right. Secondly, I have clock and radio power which assures ground but no clock or radio lights which seems to point to the rheostat on the headlight switch. I'll verify with a power check at one of the light bulbs but sure sounds like a headlight switch now. NOS switch from local Chev dealer is $20.

Regards,
Dave K.