The Stovebolt Site Forums The Shop Area The Electrical Bay No cranking

I brought my 53 3100 home from storage yesterday. I charged the battery a bit there and it started up fine. Went out today and I get nothing when I hit the stomp starter. No sound, nothing. Accessories work (except the horn; I'll work on that later) and the battery reads 12.65 v at rest. Whatcha think gives?

Turn on the headlights and have someone watch them.

Stomp the starter.

If the headlights go out it is a battery, battery cable or battery ground problem.

If the headlights stay on it is the stomp switch or the starter.

Clean the battery cable terminals.
Jerry

Thanks. The battery cable terminals are clean as a whistle. Headlights stay bright while stomping on the starter button and the battery tested fine at NAPA. Looks like it's the stomp switch or the starter. How can I test them?

Have someone hold the stomp pedal down while you tap the back end of the starter with a hammer. Don't overdo it- - - -just a moderate thump back near the brush holders. It's possible that the brushes are worn enough they're losing contact with the armature. I once suggested that to an assistant principal at a school where I was teaching auto mechanics. When he finally gave up and had the vehicle towed to my shop, there were a bunch of big dents in the windshield wiper motor!
Jerry

The switch might not be pressing far enough. The contacts in the switch do wear over time.

Find something to put between the lever and the switch, then stomp again. If it works the motor is OK.

My switch quit making contact 200 miles from home one time. I cut a piece off of an aluminum can with a pocket knife, folded it over double and formed it onto the button of the switch. Worked until I got home.

Thanks, Jerry & Bill. My local NAPA had a solenoid switch, and I replaced it - still nothing. Does that mean it's the starter motor, for sure?

I did a back yard overhaul on my starter years ago and it still works great.

Details HERE.

Sun Electric Co. had a slogan that they put on all of their equipment- - - - -"We Test, Not Guess!" Do a "series resistance test" with a low reading voltmeter and find the open circuit. Test the ground side as well as the hot one.
Jerry

I know you mentioned you cleaned the terminals but are ground wires clean and wires to starter clean. Just thinking about this

Try using a jumper cable directly from the battery ground to the starter casing to eliminate the ground as the culprit. Make sure the battery ground terminal is clean.

Thanks again for everyone's help. I've disconnected and cleaned every wire and have reached my level of incompetence. You're right about testing before guessing, Jerry, but I have no clue how to do a series resistance test so I gambled on the solenoid switch because it was available and I could do it. I've now ruled out the battery, battery terminals, cables and switch and it seems that's all there is for the starter. I found a guy who'll rebuild it and that's where I'm headed.

A series resistance check involves measuring the voltage drop across each terminal. For instance with meter probes on the battery post and the post clamp, which checks the condition of that connection. Then move from the post clamp to the ring terminal on the other end of the cable to check the cable itself (corrosion inside the insulation can cause problems.) It's best done with a load on the circuit. If there's no load, there won't be any voltage drop.

Good explanation, Kevin, but also check the conductors themselves for voltage drop. I've seen over a volt of drop in a battery cable with corrosion under the insulation, with no evidence of damage externally. The flat braided ground straps used on stovebolts are notorious for having that problem at the end terminals.
Jerry

I powered the starter directly from a battery when I got it off and it's dead. It's a 6 volt unit though I've converted the truck to 12v. The guy who's rebuilding it is converting it to 12v, too.

Try powering up the starter directly again after turning the output shaft a 1/4 turn or so. It may take off, but that doesn't mean it doesn't need rebuilding, just tells you that there's a dead spot on the commutator that the brushed happened to land on.

The "turn on the headlights what happens to the headlights to the headlights when you stomp the starter" that I suggested yesterday at noon results being "they stayed bright" is a pretty good version of the series resistance test without using an ohmmeter in this case. It showed that the battery to starter switch and the ground system was working.

Not that the series resistance test isn't useful. It is, especially when you know how to do it.

Series resistance testing is done with a voltmeter, not an ohmmeter. The idea is to measure the voltage drop across each connection while the circuit is operating- - - -something that's impossible to do with an ohmmeter. Each connection in a 12V system can have a maximum of 0.2V drop while the starter is running. A 6V system can only have 0.1V drop. Resistance values that low are IMPOSSIBLE to read with even a very sensitive ohmmeter.

For instance- - - - -let's assume a 200 amp starter current draw and a 0.2V drop across a battery cable terminal connection- - - - -that's a 0.0001 ohm resistance. I'd like to see an ohmmeter capable of measuring that resistance accurately. Also "the connection looks clean" comment- - - - -after 65+ years of doing automotive electrical work, I haven't been able to develop that much of as calibrated eyeball!
Jerry

Sorry, I should have said voltmeter as Jerry pointed out.