electrical

[DollyDodge]

I have started working on my wiring on my B-2-C and being a complete novice at electrical work I need some advice. I have a hot wire to the light switch, but none of the other light switch terminals ever get hot no matter what position the swith is in. The fuel gauge works. The blinkers wires will be hot, but not flash when the blinker is engaged (I tried a new flasher too). The panel lights terminal aren't hot either. The headlights worked when I first started working on the truck, but the first time I hit the dimmer switch they went out and I have never been able to get them to work again. None of the terminals at the dimmer switch appear to be hot. I need help figuring out or directions on how to figure out what is wrong. I have new wires coming from Rhode Island Wires (birthday present from my parents and brother).

[JBNeal]

The original drawer-type headlight switch is prone to internal corrosion that can boost resistance sky high. It's possible to run the switch back & forth a few dozen times to knock the corrosion down, but I went so far as to carefully disassemble the switch, clean the contacts, and add some dielectric grease to coat the contacts.

The dimmer switch also is prone to internal corrosion, but since I could not find an easy way to disassemble the switch, I found a NOS unit on eBay (got lucky & only helled out ten bucks). Maybe that switch needs to be operated a few dozen times to work the corrosion loose.

But the biggest culprit of all is a bad ground. I've run temporary ground wires to lights, switches, etc. from the battery to verify continuity, and most times I have found that the cumulative effect of corrosion at riveted & bolted joints can make for excessive resistance in the 6V circuit.

[pflaming]

Make certain your cab, front fenders, and bed are GROUNDED to the frame. Do not trust the old grounds (a braided strap from the engine to the cab is one, and a flat iron from the bed to the frame is another) I had a similiar problem when I rewired. I ran new 10 gauge wires to the frame for the three assemblies, doesn't matter where you do it, just short 12" wires and metal screws into freshly drilled holes. GROUND GROUND GROUND!!!!! Hope this helps.

[DollyDodge]

thank you both, sounds like grounding is the issue

[Dave72dt]

With power going into the light switch and nothing on any terminal going out in any position, you have a problem in the switch. You may have a problem somewhere else in the circuit but the lights will never work if you don't address the switch problem.

[DollyDodge]

I tried to clean the swithc with electrical cleaning spray (i forget the correct name). The switch loosened up a bunch but nothing else changed. I think it will be a process to find the problem. Anyway, I keep plugging away. Alot of my wires have bare spots in them so I also wonder if there isn't a short somewhere.

[Dave72dt]

Draw yourself a diagram of the switch and label or number the wires accordingly, remove the output wires. That'll eliminate any problems you may have further along in the harness and test the switch for any output on posts with a test light or VOM. Does the switch have a fuse built in it? Is that blown? If the switch doesn't work with all the out going wires detached, you'll have to repair or replace it.

[DollyDodge]

Shoot, I should have thought of that. I couldn't see a fuse anywhere, but once I get the switch out I will have a better look. That is my project for the weekend:)

[greg g]

Do the trucks have s fuse integral to the headlamp switch?? If so is the fuse good?

[Dave72dt]

I did some research for you. The light switch has a circuit breaker on the end of it. It may have tripped and failed to reset. There's an excellant writeup on the DEPTCA site and a wiring diagram to follow that tells you how the switch works and where the wires go. When you get back to it, tell us where you have power and where you don't and we'll guide you through it a step at a time.

[DollyDodge]

Thanks so much Dave and Greg. I will check it out and also check out the DEPTCA article.

[pflaming]

Dolly, when I 'turned on' my new wiring harness, I make certain the switch worked, used a light tester. Then I connected one wire at a time; one headlight then added another, etc. That way when something failed I knew what did work and where to look for the 'failure'. Did that for the entire harness.

[DollyDodge]

Hi: I pulled all the wires except the hot wire on the switch and it works fine with out the wires attached. High beam and tail lights are hot when the switch is all the way out, and the parking light terminal is hot when the switch is in mid position. Also, the terminal for the stop light and dome light was hot with the wires off. I wonder if there is short somewhere with wiring. The wires are in poor shape, they look ok but if you touch them all the insulation falls off. The switch was really dirty on top where all the terminals are, so I pulled it off and cleaned it up. My RI wires came and they are gorgeous and really nice.

[Dave72dt]

That's good news. Your switch and circuit breaker is working as it should. Pretty good chance of a short and popping the breaker if insulation crumbles when touched. A new harness was the only safe way to solve your problems.

[JBNeal]

If the insulation is falling off, then the wires will probably be corroded and that will increase your system resistance. It's time to replace that harness, perhaps with a temporary one made with rubber insulation. I replaced the harness on my '48 one wire at a time, long before I got a shop manual. The wiring diagram in the shop manual shows color & wire gauge; if ya wanna further decrease resistance, bump the wire gauge up to the next size, effectively broadening the electrical path of the circuit. But the 2/0 battery cables are plenty big as long as the starter is within arm's reach of the battery.

[NiftyFifty]

If the insulation is falling off, then the wires will probably be corroded and that will increase your system resistance. It's time to replace that harness, perhaps with a temporary one made with rubber insulation. I replaced the harness on my '48 one wire at a time, long before I got a shop manual. The wiring diagram in the shop manual shows color & wire gauge; if ya wanna further decrease resistance, bump the wire gauge up to the next size, effectively broadening the electrical path of the circuit. But the 2/0 battery cables are plenty big as long as the starter is within arm's reach of the battery.

Unless your a huge lover of original I would take the time to switch to a 12 system now, if your going to the lengths to replace the harness it's not a lot more work to switch to 12v and have a better system, and possibly one easier to find replacement bulbs etc.

I'm switching to 12V now, but just replacing each individual wire rather then buy a harness....also installing a fuse box to again clen things up and rid myself of fuseable links etc.

[DollyDodge]

I have the new RI harness and I am leaning toward installing it and getting rid of the old wiring. I got the RI harness for my birthday. I was going to hold onto the RI harness and wait until I did some more work ont he truck before installing it, but I think I will put it in. I can't afford to strip my truck down and restore it properly, what I am trying to achieve is a workable truck. I will paint the outside some day but for now I am working on getting it mechanically sound. I wish I could take it down to the frame. I look at the RI harness and think it belongs in a real restored truck, the wiring is so gorgeous and well made. In any event I think I will go ahead and install it. Most everything under the hood and inside my cab is in good shape paint wise, it is just the outside that looks so poor.

[Dave72dt]

Snap some pictures of where the wires are currently routed, then get them out of there and put the new harness in. The 6v harness will easily handle a 12v system with some minor changes and a couple resistors. the diagrams that come with the harness should be kept on file and be available when you get around to a frame-off. You can replace a wire at a time if you want, but replace them all, otherwise you're a rolling fire hazard. With the photos and diagrams you can easily remove your new harness and put it back in again when you decide to restore.

[MBF]

If I remember correctly on the original switch the parking light position only turned on the the tail lights-to hook up the front parking lights and make them work I put the front parks on the taillamp post too. The dome light had a separate toggle switch on the lamp housing. As long as it works and the breaker is good-you should be good to go with that switch. Mike

[Jim Gaspard]

I bought my RI harness three years ago for my frame-of project but decided to install it in my Driver for the same reason, too brittle and unraveling wires. The install went pretty quickly over a weekend but haven't been able to get my B3 started yet. I believe my problem is grounding related but haven't been able to track down exactly the problem despite plenty of advice from Forum members. When it doesn't work all you do is second-guess every step made installing the harness.

So, my advice in hindsight. Go slow. Run a test on each wire to make sure you have a complete circuit. Make sure you have good metal to metal contact when reattaching to those old terminals. Check and recheck each connection to the included diagrams which are very accurate. Also attach your headlight wiring from the bulb side of the bucket and make sure you have two pliable rubber replacement grommets where the wire passes through the bucket on the way to the terminals at each side of the radiator. As you know each section of color wires is individually wrapped and packed with a point to point diagram, so just take one piece at a time. Getting under the dash is probably the most cramped being on your back in a tight space between the seat and the pedals but its do-able. Don't rush, you only want to do this once. You should be good for another 50 years. Good luck.

[Dave72dt]

When you're working under the dash, take the time to pull the seat out and throw some old blankets on the floorboard. Your back will thank you.

[NiftyFifty]

When you're working under the dash, take the time to pull the seat out and throw some old blankets on the floorboard. Your back will thank you.

You must be wirey ...I have my seat out and no way can I fit in there laying down....someone would have to be there to winch me out after...and I'm only 230lbs...5'11....maybe age is creeping up....but that's sad...I'm only 29

I just finished my wiring tonight excpet for the turn signal switch which I may now have to find new as the one on it won't pass safety here in Manitoba....was pretty easy just running all new single wires, actually the one diagram I got from the PKC had almost everything there...excluding the turn signals in the front park lights....that you just need to decide if you want bumperlights or to solder in a new socket.

[DollyDodge]

I agree that laying on the floor isn't fun. I have my seat out and I can get in ok, it is the getting out part that is humorous. I also took out the speedometer and speaker panel which really helps a great deal. My truck runs great, it is just the lights that didn't work. I am going to start replacing the wiring this weekend. Trust me I go slow, well usually until I get frustrated sometimes:). I check and recheck everything I put back. I also have a note book that I keep track of every thing I do and keep notes on what when where (even with that said I have had a couple of challenges in putting things back). I alos take lots of pictures. The RI harness I got for my B-day is just the wiring from the dash out to the engine compartment and the generator harness. I didn't get the headlight, parking light, and body harness yet. That is next.

[Dave72dt]

You must be wirey ...I have my seat out and no way can I fit in there laying down....someone would have to be there to winch me out after...and I'm only 230lbs...5'11....maybe age is creeping up....but that's sad...I'm only 29

I just finished my wiring tonight excpet for the turn signal switch which I may now have to find new as the one on it won't pass safety here in Manitoba....was pretty easy just running all new single wires, actually the one diagram I got from the PKC had almost everything there...excluding the turn signals in the front park lights....that you just need to decide if you want bumperlights or to solder in a new socket.

Nope, not wirey at all, unless you consider 6'3" and just under 300# at 57 years and a bad knee, wirey. My harness came out 20 plus years ago and the old floor completely out a year ago. My new floor is flat except for the trans hump. A couple 4 x 4s and a partial sheet of plywood might help level yours off and make it more comfortable. I find that a light that stays putonly when shining directly in your eyes also helps. LOL

[DollyDodge]

I worked on the electrical a bit more this weekend and what I find is that the there isn't consistenet current between the hot wire terminal and the the terminal next to it. Is there a source to purchase that portion of the switch? My switch seems fine. I took it apart and cleaned it too.