Ok, so after reading several posts on wiring a truck, I jumped into my first attempt at wiring and trouble-shooting today. I am definitely an electrical noobie, so any advise would be welcome.
My '49 was re-wired by the PO who used a "Factory Fit" harness kit, and from what I can tell by looking at the fuse box, regulator, ignition, light switch and gauges, they all appear to match the wiring harness diagram. The back half of the harness was not installed, so that served as my primer in car wiring.. Simple, right? I plugged in the connector under the cab, temporarily connected the tail light wires and was able to get them to light up when I pulled the cab light switch in both position 1 and 2. Minor success, but that is all that happened with the tail lights. Turned off the light switch, and with the ignition on, the brake light would not trigger the brake pedal, so I started poking around the brake switch. I cleaned the posts and re-tensioned the connectors first, then when I did a continuity check on the switch by touching both posts with the multi-meter it read 1.0 (no continuity - makes sense with no pedal pressure), and when I pulled the brake pedal rlever (under the hood) by hand, it registered .01 meaning had continuity, so the switch seems to be working. Stumped by that, I then moved under the dash to see what else was going on with everything else.
So several hours later, with a stiff neck after contorting myself under the dash, I have a bunch of questions:
1. Brake light? Why is it only acting as a driving light and will not trigger from the pedal switch
2. Headlights - low beams do not work, only high beams after stepping on the high beam switch (even with the high beam fuse PULLED!....) I guess both low beam bulbs could be out, but that would be too easy...
3. Fuse box - high beams show full continuity regardless of the fuse being IN OR OUT. All other fuse terminals seem to behave normally with no continuity when fuses are pulled. To make sure there was no weird connection between the high and low beams, I put a fuse in the high beams, removed the low beam fuse, and the low beams did not show continuity (expected) with the fuse out, so they seem to be separate. I could not see any exposed wire or anything that could bridge the high beam fuse terminals at the fuse box, so I am confused as to how it can magically work with the fuse out (Not sure when it happened, but I noticed that the high beam fuse was burnt through. The right side headlight fizzled down to a dim glow not long after firing the lights up for the first time)
4. Dome light - doesn't seem to work. Registered 6.38 volts at the lead wire, have a good 6v bulb, cleaned up the switch with contact cleaner and even tried a brand new out of the box dome light left by the PO and neither fixture would light up regardless of dome light switch position or dash light switch position (I believe this one is always supposed to be hot). I took two wires soldered to a 6v bulb, grounded it to the cab, then stuck the other side into the dome light lead wire, and it lit up, so I am totally stumped on the dome light fixtures not working. I even checked continuity of the short wire from the dome light switch to the bulb socket, and it showed continuity, so something is happening between the lead and the bulb in both dome lights.
I have read that a "bad ground" can cause issues with electrical systems. Is that what I am dealing with?? If so, how do I track that bugger down as a one man operation?
Sorry for the long post. Trying to get everything working properly, and prevent an electrical fire which would suck after years of messing with this project!
Thanks,
Sulli
