Electrical (starting) problem

[accobra66]

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?

[68GT500MAN]

I had a similar problem with my 68, after driving it was show to turnover. I did as you did with the larger cables, but also changed the ground cable. Make certain all of the connections are clean. Did you check the battery or have a load test done at an auto parts store? I could be a bad cell in the battery not functioning right under load.
Doug

[Norm B]

Did you clean and tighten the connections at the battery. A loose connection wil cause this type of problem.

Good Luck
Norm

[accobra66]

Answers to above questions:

1.) Battery was tested, results at the bottom of my thread.
2.) Battery connections are perfect.
3.) Did re-connect grounds. Never thought of replacing the cable...how could a cable go bad unless pinched, etc?

[stack]

make sure you have good ground from battery to the frame. Use the same size as the positive connection. Then connect engine block to to ground with same size wire. Try bypassing your cutoff switch. to rule that out.

stack

[Bren]

3.) Did re-connect grounds. Never thought of replacing the cable...how could a cable go bad unless pinched, etc?

Generally, it's not the cables that go bad, but the connectors. For example, if the cable ends have soldered connections and the soldering was not done properly, the cable may not make the right connections anymore.

[Jeff Kleiner]

You told us about upgrading the + side to #2 or better cables but haven't mentioned doing the same to the ground side. The entire circuit is only as good as the weakest link; remember it has to make the full circle and return to ground. If you're still running #4 cables on the negative side step up to #2 for both the battery to chassis as well as on the block to chassis.

Good luck,
Jeff

[Boydster]

A 12 year old battery? That is astounding, Optima or not. Since your problem is intermittent, cold or hot, the battery may have acted OK when being tested but still not be reliable, start after start, after 12 years. I would try a new battery. Usually, if you can get 5-7 years out of a battery, you have done quite well. 12 years is amazing.

You should still update your grounds to match your largest power cable. But unless there is a bad crimp, connector or cable lug, I don't think the cable size would cause an intermittent start.

[accobra66]

I had considered replacing the battery last weekend but pulled back after having it tested. Did not know that batteries too can be intermittent. Honestly it feels like this could be it since it sometimes cranks so slowly. Appreciate the feedback.

[OVCobra]

Ditto on all of the comments regarding ground upgrade. Previous experience with high compression small block and rear mounted battery (fox body mustang) was resolved with running a ground cable from the battery right to the starter (used one of the starter mounting bolts), used 4-0 cables as I had them available. Wired my Mk IV the same way and absolutely no starting issues hot or cold.

Dave

[rich grsc]

Starter!!! Intall a new mini-started, end of problems.

[Doutie]

Hi, I've found Optima batteries different from typical batteries. Average life seems to be around 8 yrs. as opposed to 5 or6 for normal lead acid. At 8 yrs., Mine began doing funny things like start the car fine, drive 20 minutes, park and a half hour later nothing. Took battery to diesel shop where I work, charged battery and then tested......O.K. Couple days later I needed a jump start again. Long storey short, bought new battery and haven't had another problem since. It even started well after sitting in the garage unstarted all winter. Good luck Doutie

[CraigS]

I would replace the battery no matter how well it tested. 12 years is easily double the life I expect from a battery. I replace all car batteries after 5 years since it is just not worth it to me to have a no-start (always at the worst possible time) because I tried to save $20. Already mentioned is the battery ground cable. Don't forget to upgrade the engine to frame ground cable too. And run an extra ground cable to one of the starter bolts. All the ground cable contact points must be ground down to shiny bare metal. I then apply dielectric grease, install the bolt or nut and then cover w/ battery connection spray protector. BTW do you have a mini-starter w/ it's built in solenoid and is it wired to the firewall solenoid like this?

[accobra66]

Update: Replaced starter with high torque model and so far so good. I would stay 15 out of 15 perfect starts. Have new battery on order just to cross that off the list as I am on borrowed time anyway it seems. Thanks for all the help.