In a nutshell I am having problems with intermittent starting problems. Sometimes (~ 85%) the engine spins right over but other times I get either a very slow crank or just a single click at the ignition solenoid.

This is a carburated Mark II with a Painless Wiring harness. 351 W with compression around 9.5:1, manual transmission. Battery is in the trunk and has been tested OKAY as noted below. Cable running from trunk to cut-off switch is 1 gauge then 2 gauge as below the rest of the way to the starter. Started is a stock Ford starter (rebuilt from NAPA).

Here is where I am at.

1. Upgraded 4 to 2 gauge wire from cut-off switch to ignition solenoid then ignition solenoid to starter. This change alone clearly increased the speed at which the starter spins the motor.

2. Upon making the above change I noticed no difference. I had a very weak (if any) rotation of the motor when turning the key. Most of the time I had a single "click" from the ignition solenoid (if the system did not freely spin the motor when the key was turned).

3. Yesterday at one point found I was no longer even getting the "click" and found through investigation with my multi-meter that no current was flowing from one side to the other of the ignition solenoid.

4. Purchased new ignition solenoid and everything works better than ever. (Referencing speed of starter as noted above.)

5. Take the car out for the afternoon and find that all I get is a "click" again.

6. Get car home and take the following readings:

Key: NL = No Load on system past electrical cut-off switch; IG = with ignition key turned on and power flowing past the cut-off switch to the ignition solenoid; CR = while cranking motor over.

a.) Taken at battery
i. 12.85 (NL)
ii. 12.28 (IG)
iii. ~ 9 to 11 (9 occurring at first when motor first starts to spin then 11 once momentum picks up)

b.) Taken at shut-off switch (Inbound post)
i. 11.16 (NL)
ii. 12.17 (IG)

c.) Taken at shut-off switch (Outbound post)
i. 11.13 (NL)
ii. 12.14 (IG)

d.) Taken at ignition solenoid (Inbound post)
i. 11.12 (NL)
ii. 12.13 (IG)

e.) Taken at ignition solenoid (Outbound post) - taken at time of system operating correctly
i. ~ 9 - 11 with engine cranking.

Carl I find it strange that so many symptoms occur:

1.) Everything works 100% correct 85% of the time - spins faster than ever with 2 gauge cables
2.) Exhibits anything from full power cranking to 1/3 power cranking to no cranking (click at ignition solenoid). This happens in both times of the motor being hot and times it being completely cold.
3.) Battery is roughly 12 years old - Optima Red Top
4.) Starter is re-build from NAPA purchased two years ago. First starter I purchased from Napa was returned because of the electrical problems explained in this e-mail. After replacing with another re-built starter I have moved onto investigating other causes. Have brand new PowerMaster high torque starter sitting here that I have not installed. Alternator is a PowerMaster High Output model that was installed last year (last fall when this problem first started I assumed my alternator was going bad...clearly not the case).

Test on the battery is as follows:

a.) 800 CCA (specification new) - Tested today to 751 CCA.
b.) Voltage: 12.69 V

What seems odd to me is how the symptoms are not uniform. Why do I sometimes get a very, very slow crank, other times just get a single click and then other times get 100% normal operation. Is it possible that either my ACC wire or key switch start activation wire are grounding out someplace? If they were grounding out might this cause these type of intermittent symptoms?