The Stovebolt Site Forums The Shop Area The Electrical Bay not enough power to starter. help pls

I'm asking this for my bf, this is his first time dealing with an oldie or doing any sort of engine work. He has a 1950 Chevy 3100.
problem is... There seems to be not enough power going to the starter to crank it. Its a 6v, brand new battery. He hooked up the wires from the battery to the ignition, from the ignition to the push button starter, and from there to the starter cylenoid. He turns the key, pushes the button and the starter will only crank once.
When he's tested the voltage, everything is getting 6v.until that button is pushed, the the voltage goes down to 4v at the wire going from the push button to the starter. So not enough power to crank the starter.
There is a guy at napa auto that has been giving him advice and suggested making sure all the terminals are clean which he did. He's had the battery, ignition, and the push button tested to make sure they are all good. He even had the starter rebuilt.
What could be the problem? Why is the voltage going down once the push button if pushed? Any tips for him to try would be beyond helpful!
PS, i'm not great with the car lingo so I apologize Lol.
pss.. he put a new wire harness in and has cleaned all the parts of the engine. This was his first attempt to start it and now he's getting alittle (alot) frustrated as what could be the problem.

First, Welcome to stovebolt.

The voltage drop at the starter during cranking is normal and expected. It sounds to me like (one) the engine may have a rusty cylinder or (two) stuck valves causing excessive compression. Removing the plugs will rule out the stuck valves, and you don't want that engine to start with stuck valves.

Has he pulled the pans and inspected the insides of the engine?

What gauge battery cables (positive and negative) did he use?

They should at least be 2 gauge, but 0 or 00 gauge is better.

Make sure that all battery cable contact surfaces are bright, clean metal. It is also a good idea to cover the bare/bright surfaces with a conductive ant-oxidant grease, such as NAPA Part: BK 7652569.

I think Tim hit the nail on the head. It's the amps not the volts on these 6 volt systems that is the problem when starting. This is one time that a bigger wire going to the starter is BETTER!

Thanks guys I'll deff pass on that info to him!
yesterday he took the wires from the push button and touched one to the battery cable and the other to the starter and pushed the button and the starter cranked a few times. so were confused as to why it won't get the same result when the push button is connected to the ignition and starter. Maybe like you said above its the gauge of the cables. The wire he's using to connect the igintion, push button, to starter is 16gauge I believe.
thank you guts so much.

Ps. Once we figure this out, and the stater cranks... If the truck doesn't start, what's the next step to check.

Forgot to say YOU GUYS ARE AWESOME!

Presumably you are working with a 6v starter motor and a 6v solenoid?

Yes to both.