VCCA Home Forums TECHNICAL - GENERAL Electrical - 6 volt Starter from Dad’s ‘30 Truck   need help please

Hello. I’m attempting to get my dad’s ‘30 Truck started and I need a nudge to help me understand why the starter barely spins on a fresh 6 volt battery.

I have removed the starter and have it on the bench. When l jump it with 12 volts from my modern Truck the starter spins hard and fast. When I jump with a 6 volt battery ( purchased this morning) it spins slowly for maybe 10 seconds and then stops.

The new battery measures 6 volts with a digital multi meter.

I hollered up to Heaven to ask dad what to do next but he hasn’t answered yet. So I figured I would give you guys a shout. HA!

Thanks,
Jeff
(Dandy D’s boy)

Jeff,
Your description sounds like resistance between battery and starter. Quite often it is in the ground path between the negative cable and the starter mount on the clutch housing. Make sure that everything is clean and bright. You might get a clue if you put your multi meter on resistance and measure the path to the battery. Battery cable size and ends (both) are very often the major problem. Be sure you have minimum 2 ga (available at Tractor Supply) cables. Larger cables are better but I have found the Tractor Supply cables work well on my 6 volt cars and trucks. You can get a longer negative cable and hook it to one of the starter attaching bolts and eliminate several other connections.

Even though the 6 volt battery is new it should be well charged before using. I believe the fully charged reading should be around 6.75.

Thanks for those suggestions. Both make sense to me and I will give them go.

Also, make sure that there is no paint between the flange on the starter nose cone and the mating face on the bell housing. It should be bare metal to bare metal. And, keep in mind that the starter may need to be rebuilt as well.

Jeff did mention that the starter was on the bench. I would suggest that while it is there pull it down and clean the internals especially the brushes and commutators and all accessible connections. Over the years of inactivity the surfaces oxidize and dont conduct like they used to, it is amazing what a difference a piece of emery paper will make.
When you put it back on make sure all connections from battery back to battery are clean and tight.
Tony

Great suggestions TonyW

I like all of Tonyw's suggestions except using emery paper to polish the commutator. Emery paper contains metal (aluminum oxide) and if not completely cleaned out can cause problems as it's conductive. Garnet paper or other non conductive abrasive paper is a safer option.

I agree. Also, there is a special "emery type" of paper that is made for cleaning armature commutators that is non-conductive and that is what should be used instead of regular emery paper.

Thanks to all for your suggestions. It will be a week or so before I get back to this project. I have the battery on a trickle charger so it should have a full charge when I’m able to get back to it.

I am curious as to the "rest of the story". Let us know.

Bob

I wasn’t able to put any time to this today. (Rats!). Hope to get back to it next Saturday.

Good news. Dad’s ”˜30 started and ran well today. The new battery needed a full charge (7.1 volts on my DMM), and took time to make certain the battery cables were in good condition. Rerouted the ground cable from the top of the transmission to top starter attachment bolt. Wire brushed the cable terminals to bright shine and added star washers between terminals and their mounting points.

Thanks to all for your replies. They were all helpful.

Good to hear you had a win. With 6volt electrics everything needs to be very clean.
Tony