Starter wont engage
It should not take this long to troubleshoot a problem of this sort
You say you can turn the engine. Have you turned it TWO complete turns, which is a complete engine cycle?
You mentioned "ground to the firewall." We may be assuming things. You should have the MAIN battery cable from battery NEG direct to the engine block. At least one additional ground should go either from the engine block OR battery NEG to the body
The main POS cable should either go to the starter relay stud and then to the starter, or else go direct to the starter, with a second cable from the starter up to the starter relay post.
The starter SOLENOID wire goes from the small terminal of the starter up to the "square" terminal of the starter relay
BATTERY CABLES can corrode internally and battery CLAMPS can appear to be good, when "not." You MUST clean the battery posts with a proper cleaning tool:
YOU MUST get a voltmeter and make some checks
Get it down to SIMPLE IE eliminate all wiring, relay(s), etc.
This means use either a starter button or a screwdriver to short
1-- between the starter relay battery stud and the "square" terminal of the relay.
2--If that does not work, jumper directly across the two terminals on the starter.
3--Clip your voltmeter onto the starter main (large) terminal, and to the engine block. DURING the time that you are jumpering the relay and attempting to start the engine, you should see at least 10V at that point. If you do not you have one of the following problems
1---A bad battery cable or terminal. Any smoking, sizzling sounds are an indication of poor connections
2--A bad battery. You seem to have substituted a good one, but suspect connections
3--A bad starter. It does happen
4--A dragging engine, or other problems with the starter mounting, mud, dirt in the bell/ ring gear, etc.
I've fired up three engines in the last few years just "hanging off my hoist" using nothing more than booster cables from the battery to the starter, like this:
This is one:
It should not take this long to troubleshoot a problem of this sort
You say you can turn the engine. Have you turned it TWO complete turns, which is a complete engine cycle?
You mentioned "ground to the firewall." We may be assuming things. You should have the MAIN battery cable from battery NEG direct to the engine block. At least one additional ground should go either from the engine block OR battery NEG to the body
The main POS cable should either go to the starter relay stud and then to the starter, or else go direct to the starter, with a second cable from the starter up to the starter relay post.
The starter SOLENOID wire goes from the small terminal of the starter up to the "square" terminal of the starter relay
BATTERY CABLES can corrode internally and battery CLAMPS can appear to be good, when "not." You MUST clean the battery posts with a proper cleaning tool:
YOU MUST get a voltmeter and make some checks
Get it down to SIMPLE IE eliminate all wiring, relay(s), etc.
This means use either a starter button or a screwdriver to short
1-- between the starter relay battery stud and the "square" terminal of the relay.
2--If that does not work, jumper directly across the two terminals on the starter.
3--Clip your voltmeter onto the starter main (large) terminal, and to the engine block. DURING the time that you are jumpering the relay and attempting to start the engine, you should see at least 10V at that point. If you do not you have one of the following problems
1---A bad battery cable or terminal. Any smoking, sizzling sounds are an indication of poor connections
2--A bad battery. You seem to have substituted a good one, but suspect connections
3--A bad starter. It does happen
4--A dragging engine, or other problems with the starter mounting, mud, dirt in the bell/ ring gear, etc.
I've fired up three engines in the last few years just "hanging off my hoist" using nothing more than booster cables from the battery to the starter, like this:
This is one:
