The Stovebolt Site Forums The Shop Area The Electrical Bay dead truck, electrically

i have an electrical gremlin somewhere.

for a 1952 3/4 ton:

prior to the gremlin showing up, the brake lights would function regardless of what position the ignition switch was in.

after some sitting, i get no power anywhere. starter won't go, headlights don't work, nothing. the battery is brand new btw.

thinking that the old ignition switch could be accidentaly left in the on position, and the key removed (it can, apparently the tumblers are useless) i tried a known good battery from another car. same story.

questions:

1) from looking at the wiring diagram, it seems that the starter should spin even if the key is in the off position. true?

2) what wires do i jumper together on the ignition switch to eliminate the switch as the culprit?

3) where are the fuses supposed to be? (wiring is pretty messy, previoius owner redid most of it and liked red)

this problem was just discovered last night, and i didn't have enough time to try any diagnosis. if anyone has some odd things to look at i'd appreciate it.

the thing that really puzzles me is the brake lights. they should work no matter what.

-bryan

If you have a floor starter the problem has to be in the cables or ground. Check the connection on top of the starter. Check the ground cable. If it grounds to the frame than you must have a heavy gauge ground strap from the engine to the frame. When you solve that the rest should fall in. I,ve seen those 1 color wireing jobs. Sounds like you are going to need a whole harness.

i solved one problem, sorta, last night. the ignition switch was indeed left in the on position. i extra double confirmed this by popping the distributor cap to find a small pile of ash where the points were and a melted condenser wire. the new battery now reads less than 1 volt. oh well. at that point i had other things to do so it got pushed into the garage for another day.

so wrenchbender, should i be able to hit the starter switch (it is a floor start) even without the ignition switch in "on" and it will spin? all the proper cables are at least present, though i haven't checked their condition as far as the continuity goes. the puzzler is that it worked really well about a week ago, week and a half maybe, and now nothing. the only thing that changes is the ignition switch was left on untill yesterday. what else can burn out in that situation?

If you hit the switch, the starter will spin anytime.

With your switch in the On position for exended periods, most of your iginition system takes a beating. Points, cond, and maybe the coil will all be toast.

If the wires are original, they are probably in pretty tough shape. My wiring system is all factory and in need of replacement. If some P/O decided to rewire or repair, I would hack out the repairs and buy a new harness. A new elec system is pretty cheap.

thanks for the info 46

the starter switch is the really puzzling thing to me. i tried another battery, no response from the starter

as far as ignition goes, i'll probably toss a pertronix setup in there and be done with it. truth be told i'm not the one that left the switch on, and it'll happen again i bet.

Your battery should have a big ole heavy strap/braid going to ground, and a big ole heavy wire going to the top of the starter.

When you hit the foot switch, you're completing the circuit to the starter motor, so if you have a good battery, and solid battery connections, the starter should crank regardless of the ignition key-switch position.

First thing i'd do if I were you would be to disconnect the smaller wire from the top of the starter, so the only thing you've got going to the starter is the hot side of the battery.

If the battery is good, and the starter still won't crank, and you're ABSOLUTELY SURE YOUR BATTERY CABLES ARE GOOD, AND HAVE GOOD CONNECTIONS ON BOTH ENDS.. then i'd say next you would wanna check the actual starter switch.

With the battery disconnected, take the two screws out that hold the switch in place.. this is just a spring loaded hunk of metal that makes connection between the terminal and a bare nub on the starter. This area tends to get corroded and full of crud. I use a toothbrush sized wire brush and some WD40 to scrub 'em out good.

If you removed the starter all together at this point, you could hook some jumper cables to a battery, clamping the ground to the mounting flange of the starter, then the hot cable to that "nub".. the starter outta spin.. if it dosen't, either you arent following the directions right, or your starter is toast.

If the starter behaves normally with the rest of the truck wiring removed from the circuit, it could be you have a wiring SNAFU somewhere down the line thats sucking your battery dry, and thats why the truck won't crank.

thanks again

the connections you describe are all there. none of them would i describe as big or heavy, but they are adequately sized. i haven't had time to inspect the integrity of the individual connections though.

a buddy of mine suspects the starter has siezed. it think that is pretty unlikely but your tips should help diagnose that. actually when i connect the spare battery and press the starter switch i hear a little snap which sounds like a spark. the battery terminal leads aren't tightened down all the way due to frequent removal, so maybe the starter is siezed and the little gap around the terminal arcs instead of the starter spinning. just rambling there.

hopefully i'll get some time this weekend to figure things out.

a side note i'm confused about: i've read some posts around here referring to positive ground but there wasn't enough info for me to tell what vehicle was in question. mine has a cable going from the negative post of the battery directly to the frame. is that enough to say for sure it is negative ground?

if it's a Chev, you have neg ground [pos on early GMC's], and yes the problem will be in the switch on top the starter, which was no doubt quite worn just thru age, and got a bit too much corrosion crud thru all your adventures, so stopped making contact - may be cleanable, may need replacement, but I'd bet the starter itself is not stuck

Bill

thanks bill

it is a chevy, negatve ground yessss!

BRD my guess is that the switch is burnt. This is cause buy trying to spin the starter with a low battery. The switch will just arc and there isn't enough voltage to move the starter. Do this enough and the switch will become junk. Take it apart and see what you got. Clean it and try it may or maynot work but the cost is just some time. Replacement should be available at a good parts store. Good luck.

I've brought three trucks back from the edge.. all three hadn't been run in at least 20 years. All three were pre-53 (one was a Dodge) and all three needed to have that foot stomp switch cleaned out before they'd do anything.

If your local autoparts store stocks that top of the starter mounted switch, replacing it would probably be the best bed, but i'd test the starter motor itself with the switch removed using the method I mentioned above first thing.. that will tell you quick if your starter has given up the ghost.

In my experience the battery terminals don't have to really be tightened down.. I regularly play musical battery between the three trucks and my Farmall M.. I just pop the terminals on by hand and turn them till they snug a bit and off I go.. but you wanna make sure your cables are good.

Just because both ends look good or are clean dosent mean there isn't some corrosive funk living somewhere in the cable.

fumblin.... the stomp switch is first on the suspect list. actually, it's tied for first with a bad cable or connection. i just need some time to look at it. 24 hour days are too short sometimes.

ok i finally got some diagnostic time....

the stomp switch is fine, diasssembled it, cleaned, checked it with a meter. i also compared it visually with another one that is way more eroded and both failed to spin the starter. the current starter is rebuilt and the copper contacts are barely used.

at one point i had the battery hooked up and had the volt meter on the switch. one porbe on the (+) lug and the other on the switch housing reading +12ish volts. i then closed the switch and voltave went to zero. to me this is more evidence the switch is fine

the starter is fine, it passed the jumper cable test

the battery ground cable measures no resistance

there are 12 ish volts between the (+) lug on top of the starter and the frame, and no measurable resistance between the frame and starter housing (the part that actually bolts to the bell housing.) i believe the engine, therefore starter, ground is fine.

i also tried using jumper cables to ground the battery directly to the frame near the motor: still no luck.

any other suggestions?

anyone concur that the switch is acquitted of wrong doing?

how about the ground cables?

thanks all for the help.... next opportunity to play is monday

-b

Well if it were me this is what I would do. First I would pull the starter, Clean the contact surfaces on the starter and engine block. Remount starter. Install new 0 gauge or bigger ground strap from starter mounting bolt to frame. Install new negative cable (0 gauge or larger) from battery to frame. Install new positive cable from battery to starter. Make sure all conections are clean and tight. Then start your truck and drive it.

If that don't work I don't know other then trying a new starter?

Good luck!

Load Test your new battery. Just cause it's new don't assume. When you test your cable leads, Tug, Push/Pull and Wiggle them as you read the dial. Of course large gauge to both.

I second having the battery checked, I just fixed a starting problem on my tractor and it turned out to be the battery. I was sure my battery was fine, since it had never showed any weakness up to that point and when I tested it with my multimeter it read 12.5V. I could not start it with my battery charger connected and on the 75Amp starting setting, but when I jumpered it with known good battery it started up fine. I was surprised that I was not able to start it with the battery charger, but apparently the 75amps was not enough to kick it over. BTW the charger light indicated that the battery was fully charged as well. I spent a lot of time looking else where for this gremlin before I came back to checking the battery.

the battery i'm using for trouble shooting has no problem turning over and starting the 350 in my blazer. the "new" battery is sitting on the floor looking pathetic, with no charge on it. it's probabyl toast.

I'm having a similar problem in the '49 1-ton (6 volt). My battery checks fine and I cleaned all the connections. When I stomp the starter button, it turns over sluggishly for one turn and then quits and I get nothing after that. Is this a similar problem to Bladredhead's, or indicative of something else?

I had a similar problem a year ago and switched out the starter with another one I had laying around. That seemed to fix the problem. Now I'm having the problem again.

This weekend, I'll pull the starter and clean up the switch. I'll also clean the connections on the engine-to-frame grounding strap. And I didn't even think about checking the resistance on the ground wire... Lots of good ideas above and very timely!

Thanks,
John

I took my starter apart and sanded all the contacts and magnets with wet/ dry paper. Put it back together and worked great. Quick job too.

6 volt systems need DOUBLE OTT (00) cable! Anything less and you are wasting your time. Until you have the proper cables in place, nothing else matters. And don't use dielectric grease on the connections, use vaseline or specialty electric goop for good connections. Add a ground from firewall to engine. Main ground strap should go straight to the starter bolt. If you guys want radios and the like then go 12 volt by all means. But if you just want your truck to start well and have bright lights, etc, then keep the 6volts and do it up right. Headlight relays are a good idea as well. thye are available in 6 and 12 volts. And if your taillights are weak, run individual grounds from each one to the frame. (Oh, and if you're putting 8volt batteries in 6 volt sytems, :mad: )

it's been a while since working on the truck, mostly out of frustration.

anyway, i used jumper cables to go around the stock wiring, then found a bad ground strap because it was loose. tightened it and all was good.

had to wait a week, and the same symptoms were back. juper cables and a little scientific method application told me the positive cable was bad. i just replaced the darn thing, and the new one is RED like it should be.

anyway, now on to the distributor. i tried points, gave up and the pertronix is just waiting for my time to install.

of course, there is the matter of the vanishing brake fluid too but that is what the new wheel cylinders are for.

oh joy