Trouble starting


New Member
Oct 26, 2022
New York
Hey everyone,

I’ve been running in circles trying to get my mustang to start. I have a 66 mustang l6 200 with a 136 tooth flywheel. I’ve been through 2 new starters and keeping coming across the same problem where they have a hard time spinning the engine. I have a new battery that’s working fine, I turn the key starter try’s to engage and then smoking.
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Mach1 Driver

Nov 11, 2022
How difficult is it to turn using a breaker bar on the harmonic balancer?
If smoke appears this test may be difficult, but I would do a voltage drop test...lets see if I can upload a picture on here


The biggest killer of starter solenoids is high current. This can be poor connections, starter heat soak, poor grounds, or low battery voltage.

I’d do voltage drop tests on the starting circuit. You do these with a fully charged battery and the ignition disabled (pull the wire off the coil + terminal) so the engine won’t start when cranked and watch your fingers with the belt and fan.

The typical voltage drop values should be:

1. Battery post (positive) the front big lug of solenoid, while cranking the engine: no more than 0.1v

2. Front big lug of solenoid to rear big lug of solenoid while cranking: no more than 0.1v

3. Rear big lug of solenoid to big post on starter motor while cranking engine: no more than 0.1v

4. Battery post (positive) to starter motor housing while cranking: no more than 0.5v

5. Battery post (negative) to starter motor housing while cranking: no more than 0.3v

6. Battery post (negative) to engine block/head/manifold while cranking: no more than 0.2v

If the circuit has too much resistance (voltage drop), when the contacts inside the solenoid are forced together, excessive heat will be generated which can fuse the contacts together (stuck solenoid), arc (burn) the contacts, preventing a complete circuit (clicks) or melt plastic preventing the magnet from sliding properly.