1967 Belvedere hazzard switch and other wiring questions

[superbee_68]

I am troubleshooting wiring gremlins on my 1967 Belvedere restoration. I purchased a nearly perfect original dash harness. The headlight, engine, tail lamp, reverse light, and neutral safety harnesses are new. After installing all the wiring, some strange things are happening. One thing I noticed right off the bat is the plug for the hazard switch has all four pins next to each other in a 2x2 pattern. The hazard switch has four pins but one is not in line with the others and is not plugged into the connector on the harness. My original harness had this same plug. Do I have the wrong hazard switch, wrong connector, or is something else going on? Any help is much appreciated.

Symptoms include:
1. with headlights off, when you press the brake pedal, the parking lamps on the dash and brake lights light up
2. headlights on, brake lights stay on constant
3. hazard lights do not flash
4. turns signals work on dash indicator

Neutral safety switch is also not working. Changed from 3 pin to single pin switch on big block 727. Is there more to it than just changing the switch?

Blower motor is not coming on? This one should be easy to fix just have not tried yet.

 

[richard]

Almost thru with retiring my 67 gtx. First thing to do is disconnect the alternator hot wire and the voltage regulator hot wire so that you can leave the ign switch on while you are testing the wiring. Get a wiring schematic. Study it closely. Sounds like the hazard switch is the correct one, not sure why the connector does not fit all four wires correctly. My suggestion is to work on one circuit at a time (I.e. Hazard lights) Understand how the individual circuits work and be patient. Wiring is the hardest thing to do on a car IMHO.

 

[superbee_68]

I figured out the problems and figured I should share. The first problem was the hazard switch had dirty contacts internally. I pulled it apart, cleaned it, and put it back together. The switch ties all four posts together when the switch is flipped and is open circuit when the switch is off. I made some short jumpers to adapt the plug in my harness to the hazard switch I have. Now the hazard lights worked but the brake lights still turned on the dash lights and the tail lights came on with the headlights. After hours of testing, I ended up finding the culprit. One of the new 1157 tail light bulbs was manufactured incorrect. The tail light and brake light filaments were shorted together, allowing the brake light circuit to backfeed the parking light/tail lamp circuit. I would have never guessed brand new bulbs would be the problem! I changed the bulb, and everything works great! If you are having wiring troubles of your own, remember that it could be as simple as a bulb.

 

[miller]

Good stuff, superbee_68! Thanks.

Glad you figured it all out.

 

[Cranky]

Some years back I replace all my dash lights in my 66 Belvedere and went to test them out before screwing in my cluster. Well, it took me a few hours of trouble shooting thinking I messed something up but if the cluster isn't grounded, all kinds of crazy stuff happens lol. Once I screwed in the cluster, all was fine.