Technical SBC won't turn over. Update

I went to drive the Model A to breakfast yesterday and it wouldn't start. This is probably the third time it's done this once in the spring and once last week.
It got a stock 1963 283 with the bell housing
Mounted starter about 3 years old.

I press the starter button, the voltmeter on the dash drops from 12.2 to 10.2 but nothing happens. If I get out and momentarily jump the battery terminal to S I can get back in and it starts normally.
Today I put my multi meter on the S and got 9.2V at the terminal but I still got nothing. Again a 1/2 second jump to S and it starts normally.

I'm thinking that the 9.2V at the starter should be enough too pull in the solenoid so I'm blaming it. I like other opinions before I pull the starter. There's probably less voltage drop when I us my screw driver to jump the solenoid but I don't think 3 volts is exceptional in the starting circuit with the start switch and clutch switch. Let me know what you think.

Phil

 

what is battery reading? should be 12.6. checked for system drain?

 

12.2 by the dash voltmeter and 12.4 with my multi meter at the battery. I'd say the same with a margin of error. Also I have a battery cutoff switch which is off when parked overnight.


Phil

 

10.2 at volt gauge then to 9.2 at the S terminal means your loosing current some where. Is it to small a wire, bad terminals, bad safety neutral switch, ignition switch? Also is that 10.2 because of amp draw pulling it down on reading or a battery issue as well.

 

Jump around your cutoff switch and see what happens. The switch may have burned internal contacts.

 

If you only get 9.2 volts at your S1 terminal you have a really big voltage drop. I would go right to the battery and measure the voltage drop from the post to terminal on both battery terminals and across the cut off switch. You have to connect the DVOM (voltmeter) leads across the connection and try to start. The DVOM shouldn't read more than 0.1 - 0.2 volts. I suspect you will find one with 8 + volts.

 

Phil if you need an extra hand for an hour or two just pm me, we are neighbors after all...no electrical guru here but sounds like you are in good hands here with those in the know...one thing I do know is grounds are dang important...how old is the battery...they are notorious for just saying sayonara any time they feel like it...

 

What happens with an extra battery?

 

He may not have one? If his battery is near new it may not be the culprit but again new means shit nowadays but there are warranties though if it is still under it...again if it's the problem...

 

Thanks, maybe next week, it will be hard to test the switch under the car and press the switch in the car.

Phil

 

This a great tester to have for one man bumper to bumper testing.

 

You very well could be right, it could be any one of those items or a combination of them.
I thought the voltage drop was a reasonable amount but wasn't sure, I will try to narrow it down later after taking care of some house repairs.

Phil

 

Can I suggest a relay mounted close to the starter drawing supply directly from the starter + post. Use the existing starter solenoid wiring to drive the relay.
Maybe use an old school Ford type starter solenoid/relay to help it look appropriate. That will substantially reduce the load on the existing starter wiring/switch etc.
Good luck.

 

Run a Jumper lead from the Battery + direct to the starter + post [eliminating all connections in between]

If it still shows a massive voltage drop then it is probably the starter motor or solenoid.
I've had worn bushings in the starter cause this [the armature becomes off centre]

 

I run a Ford solenoid on my car, started using them when I had stock cars.

 

I wonder what the amp draw of the ford solenoid is compared to the chev built in solenoid.

Phil

 

Have you checked the main ground connection to the engine to see if it has any corrosion? Remove the bolt or stud and clean the threads in the block and on the bolt/stud. Bad ground connections often cause inconsistant grounding as well as complete lack of grounding. Sometimes its the simple things that we overlook.

We had a Chevy pick up at work that gave us a starting problem. They towed it to a Dealer and he charged us for replacing the grounding stud with a new one. Truck started fine for about a week and then did it again. One of the shop maintenance guys crawled under the truck and removed the stud. They had simply cleaned the external part of the stud instead of replacing it. The internal threads had lots of corrosion. He cleaned the internal threads and the threads on the stud that screw into the block...then reinstalled it. No more problems after that.

 

I didn't have time last fall to do anymore work on my starting problem but as I recall it happened one more time before the end of the season.
I moved the car around the shop this spring and it started fine every time. I decided to try and head off any problems this year and add a ford type relay.
Measuring between the +battery terminal and the si on the gm starter relay I get a voltage drop of .6. After hooking up the ford relay and moving the start wire from the start button (it goes through the clutch safety switch) to the ford si terminal I only get a .1v drop.
I'll see how it goes this spring.



Phil