Ok all, so I’ve spent more than ten years restoring my 51 Chevy COE. She’s absolutely beautiful, but it will all be for naught if I can’t figure out the electrical 🤪. I kept her 6V as original and everything’s been rebuilt with 6V parts...starter, generator, signal switch, flasher, bulbs, etc. Just got a 6V battery installed. Dome light works, dash lights works, brightness level when rotating headlight switch works. The headlights and parking lights work...sort of. When I pull the headlight switch out to the first position (parking lights only) actually illuminates the headlights (the dimmer switch does work 😂) Pulling the rest of the way out (headlights and park lights position), the headlights go off and the parking lights come on! Turn signals don’t work...well, the flasher does its thing but no lights blink.
So I pushed the headlight switch all the way in, and let it sit overnight. The next day, the battery is dead, I mean totally dead. I wired the headlight switch and ignition switch as shown in the attached pics. In full transparency, I don’t yet have the the rear turn/tail/stop lamps wired up (wiring is run, but currently ‘open’ - no wires are touching any others or anything steel.) I also don’t have the fuel tank sender grounded yet. Could either of these be causing? Everything else electrical is connected.
You may have 2 problems. Killing the battery would suggest a short. When I have rewired something, the first thing I do before hooking up the battery is to put an ohm meter to the battery cables. With everything off, and assuming no shorts, you should have infinite ohms or lack of continuity. Or you can hook up one cable and drag the other across the post and in weak light you might see a spark. I just don't want to have an electric fire and burn up an expensive harness. If you have a short somewhere, then you have to find which circuit(s) might be involved.
The second issue relates to the wrong lights coming on. You could have mixed wires up, the switch may be bad or the harness is wrong. Only you know what items are new to your truck and which have been used before and proven to be good. For example if your switch worked before, it is highly unlikely that it is the problem.
The switches were all the same and they do fail. I'd bet this is your problem if no lights stayed on and none of the open circuits were grounded when the switch was off. I'd get a handheld tester, remove the switch completely and test all functions of it. Good luck. The replacement switches will work but don't really match the old ones exactly.
Thank you so much for the feedback and ideas. I’ll definitely check them out and get some pics ASAP. FYA - everything is new. The harness, the headlight and signal switches, the lights/bulbs, the ground cable, the battery, etc. I’d say all the grounds are “clean”, as in, there are bolts or screws through everything and all thread into virgin metal/threads. Is it possible that the surface area isn’t enough? For example, I may need to strip some paint off the Xmsn housing for the main ground? Does the headlight switch itself ground through the dash? Also, the rod in my headlight switch doesn’t quite go all the way “in”...it stays “out” about 1/8”...is that normal?
Hi Derek, Your switch is broken. It is suffering the same problem I showed in a post on this same section. As long as you can't push it in all the way, it will be making contact and draining your battery. Please see my post and let me know if you have any questions.
Thx Jon, I saw your post ironically enough. So that even happens with brand new switches? It’s never gone all the way in and I was thinking the issue you describe happens when it actually goes “too far in”?
The tip end of the rod is sharply pointed, Derek and there's just a wee bit of room between the tip and the bakelite end. Maybe 4 thousands of an inch. And bakelite can be extremely brittle. So the combination isn't a good one. I think the damage happens when the rod retainer groove gets worn, but apparently if you had a problem with a new switch that's not so. I was assuming your headlight switch was an original one. The import switches are different...not the same design at all, and I don't know where you would find a new Delco original switch today. Maybe somebody has some old stock on eBay, but it would be expensive as all getout. Take a look at this one (which I bought to study). Each of the brass rivets on top is a contact point inside the switch. I haven't opened it yet, but just looking at the top I can see a world of difference...and there is no way to release the knob rod.