Starter problems

[Riley012]

Just replaced batteries on my 1982 Chevy pu. It has the 6.2 diesel and the starter just clicks sometimes when I turn the key. I put the charger on it and put the 50 amp boost on and it will turn over. Can anyone give me some advice on why this happens sometimes. Thanks

[RustyPile]

A diesel engine has extremely high compression so the starter and all related components must be top notch condition. The list is very long.. Did this problem exist before the battery change? Assuming both batteries together are producing at least 1500 - 1800 CCA, and fully charged.. The cables and battery posts should be very shiny where they connect to each other, including where the cables connect together.. The solenoid could be bad.. The starter itself could be bad.. It's at the bottom of the list but don't rule out internal engine problems.

[Dead Parrot]

Possible the starter brushes are near End of Life. Intermittent contact is one of the symptoms. Same for a near EOL solenoid.

give the battery cables a good look over. Cable internals can be bad while the cover looks great.

Don't overlook the possibility that one or both batteries are bad out of the box. Rare but it does happen. Disconnect one of the cables so the batteries are not in parallel. Let it sit for a few days then check with voltmeter. If one is much lower then the other, suspect bad battery.

Any chance a stray circuit is staying on and slowly draining things?

Is the brace still on the starter? Often skipped during starter replacement. On the 6.2, it is needed to keep the starter properly lined up due to the extra torque needed to start.

[Axle]

Easy battery cable test is a voltage drop test on them, put one probe on the battery terminal, the other on the starter battery post. Crank and watch the voltage. If you are measuring volt(s) you got a bad cable, bad crimp, dirty/loose connection. Acceptable is up to .1 volt (point one volt).

Whats the voltage on the batteries after sitting overnight? And after trying to crank it over?