The Stovebolt Site Forums The Shop Area The Electrical Bay Truck electrical problems

Hi, new member here.

I'm having some problems with my '49 Chevy 1/2 ton. To be succinct, it don't too good. Still running on original 6v system, starter was rebuilt properly and converted to high torque, cables were made custom out of heavy guage wire, starter and battery have been properly grounded, battery is an Optima and starts my '54 2 ton flatbed no problem.

-It will only start when battery has been on the charger and is at 100%
-If I turn it off after driving for some time and immediately try to restart it, no joy. Starter makes maybe 1 revolution and quits
-I tried a 12v battery jumper on the advice of my mechanic, no dice

Tonight I took some jumper cables and made two new grounds, one from the battery terminal to the frame and one from the ground on the underside of the starter to a different spot on the frame. There was no difference in cranking at all and the truck did not start. I did this when everything was cold and the battery was at 100%.

Any help woukd be greatly appreciated!

Might be time to pull the starter. Look for worn bushings and rub spots on the field coils. Good brushes and a clean armature will help as well. You are talking about a very high current system with low resistance and any cruddy contacts or extra drag will not be helpful. That 12 volt battery should have spun the starter like it was on steroids. You have done the right thing with the cables so now it is time to look at the starter. There is a copper contact that can wear under the switch cover. I would look at that as well. The switch is available from lots of vendors including NAPA the bushings and brushes are as well. The starter is simple to take out, and apart so not to worry. Use big rubber bands to hold the brushes away from the armature when you pull it apart and put it together and it should be not too tough to fix.

Starter was rebuilt last week, new brushes, bushings, switch and everything. Bench tested also.

I've actually got it to start today with the 12v battery jumper and pressing the gas pedal at the right moment.

steve_h I think you missed the part of the starter being rebuilt. I think it may still be the starter but I think it may be too tight. It may be that the rebuilder built it as if it were going to use 12 volts. It may have too much friction. Creating too much load.

If it were me I would pull all the fuses out of the fuse box that are not used for the starting circuit. This will keep you from burning up any of the 6 volt accessories. I would then bolt in a 12 volt battery and see if this starts your truck.

Just to see, I think I would pull the starter and momentarily touch it with a 6 volt battery on the shop floor. It should turn freely. Then you could fix it or eliminate it from the problem list. Be careful when you do this. It will want to jump around on you if the armature is free.
Let us know what you find.

Mark

Well I fixed it. Looks like when they rebuilt the starter they added a bushing to the shaft and that stopped the pinion gear from engaging the flywheel fully. Not sure what the thinking was on that. Tiny little bushing caused a big headache!

Glad you found it. I did miss the bit about the starter being rebuilt,...but with a stomp starter and good (big) cables...there is just not much left. I have seen much stranger things from "rebuild" shops. Good shop is a treasure. Keep them in business if you can.

Good news that it was some thing that you could fix. These trucks while being "Simple" have the ability to present us with some very complex scenarios.