Intermittent Starting

[NolaBoy]

I have a ‘76 with a 302. I have been having trouble with starting. I have upgraded the starter to a PMGR. It will start fine if it gets power. When I turn the key I either get absolutely nothing to happen or it starts fine. It has a new neutral safety switch and battery. I changed the starter solenoid but that didn’t fix it. I took the starter to a store and it tested fine.

I am wondering if perhaps since it usually works the first time I try after letting it rest if the starter passed testing but the solenoid in the starter is bad. Is this possible. Any other ideas on how to troubleshoot? Thanks!

Jimmy


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[DirtDonk]

It’s always possible for the problem to be in the starter. Rare that they’re that intermittent, but not impossible.
And the more new parts are thrown at it, the more variables are added to the mix. Don’t throw away your old starter relay. In fact, don’t throw away any of the old parts!
Next time, it’s very easy to test a starter relay/solenoid right on the vehicle in a couple of minutes to see if that’s the problem.
Saves you trouble and money. And frustration.

When it does it, is there even a click of any kind that you can hear? Or nothing?
When it happens, is everything else go dead too? Or do all the accessories, such as headlights, heater, and such?

 

[DirtDonk]

Speaking of crappy parts by the way. The replacement Ford starter relay is probably one of the most unreliable parts that are forced on us these days.
The original ones could last 50 years, or more. New ones are hit or miss right out of the box.
The less you pay, the more likely, you are to get one that only works a couple of times. If at all…
This makes diagnosing a bad one extremely difficult. You can no longer assume that a new part that you put on is no longer the problem.

 

[DirtDonk]

When you installed the new neutral safety switch, did you go through the adjustment procedure? Have you tried jiggling the shift linkage when you’re trying to turn the key to start?
Is it a stock column shift still, or something aftermarket?

 

[DirtDonk]

Sorry for the barrage of questions. Just trying to get everything thrown out there as it comes to mind.

 

[NolaBoy]

I have not adjusted it but I have jiggled it and it doesn’t seem to be the issue. It is a stock column shifter. I know the starter relays are unrealiable. I did try two. I already had one around. I haven’t been able to listen for a click on the new one but I didn’t really hear one on the old one which is why I switched it.


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[DirtDonk]

Do a quick test then. As described above, pull the red with blue wire off of the “S“ terminal of the starter relay.
With a jumper wire, or a metal tool (like the screwdriver suggested) touching between the battery side lug and the small S post.
Make sure the transmission is in neutral or park, and the brake set. Don’t have your hands near anything like a fan in case it does decide to crank.
Leave the key off, and just touch the small post.
You should hear a click and immediately the starter should crank.
Even though you’re expecting it, it has startled more than it’s fair share of mechanics!

If the starter cranks, then there’s nothing wrong with anything between the battery, starter relay, and starter. There’s something wrong with the power not getting to the S post from the ignition switch.

 

[NolaBoy]

Sorry, it’s been awhile. I have been in and out of town. I did test this and it did crank with a screwdriver from the s post to the hot post from the battery. So it seems there is an issue getting power to the s post correct? Any ideas on what to check next? Thanks!


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[DirtDonk]

Yes. Fairly straightforward, at least initially.
There are only three areas that would typically be at fault, and only two that are common.
1. Ignition switch going bad.
2. Neutral-safety switch. (If an automatic transmission)
2a. Jumper wire. (If a manual)
3. A loose connection at the S post.

A fourth possible area, would be some compromise in the Red w/blue stripe wires between the switch and the starter relay.
But so far that has proven to be very uncommon. Usually the wires are still good even 50 years later. Other than that little 90 degree push-on connection getting loose on the relay.

But the jumper wire, on the other hand, is a common failure point.
Since I think you said you have an automatic, you will have to test the neutral safety switch. There will be no jumper wire to go bad.
Easy Peezy, though.
Find the four wire connector at the firewall between the body harness and the neutral safety switch. Disconnect it and test for power coming in on one of the red with blue striped wires when a helper turns the key to the START position.

If you see 12 V at one of the wires, then create a jumper wire of your own and shove it in the two holes with the red and blue wires. Be careful because this is bypassing the neutral safety.
See if the engine starts consistently after that. If it does, guess what? You have a bad neutral safety switch.
When they are bad, wiggling them seldom shows that fact.

 

[NolaBoy]

I did replace the ignition switch (I had already replaced the neutral safety switch.) The first time it cranked no problem! Then nothing. Is it possible the cylinder is the issue? I had noticed recently the key would come out no matter what position the cylinder was in. In addition I just noticed that there was trouble turning it to the ACC side and even when I did the accessories didn't get power? Thanks again for all your help!

 

[DirtDonk]

Well, normally, no. The cylinder merely turns the switch, but the switch does all the work.
I suppose you could test that theory by removing the cylinder and turning the switch with a screwdriver directly. If it’s still resists, turning into ACC and doesn’t work, then your new switch is defective.
If you’re not getting power to the appropriate spots, including the starter relay, when turned to START, then the switch is defective.

 

[NolaBoy]

Ok. I tried that. The acc works. Also, no binding. Still only starts intermittently. It will start a few times then nothing at all happens other than the voltage meter responds to me trying to start. I’m at a loss. Wondering why it cranks easily a few times then I get nothing at all?


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[Oldtimer]

. . . other than the voltage meter responds . . .

Explain response.
Stock cluster has ammeter.
Has it been replaced with a volt meter.
If ammeter, is it moving to negative when key turned to START position?
If volt meter, what voltage shows in ON position, and what voltage shows in START position?

 

[NolaBoy]

Sorry. Yes, the ammeter was exchanged for a voltmeter. In the on position it is between 10-12 volts. It does go down when starting. The battery is also brand new. The interesting thing is that it starts fine at times. No hesitation or anything. Other times nothing happens at all. No crank at all. Just silence.


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[DirtDonk]

When it doesn’t crank or start at all, what does the voltmeter show when you turn the key to the START position?

 

[NolaBoy]

It drops all the way down.


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[DirtDonk]

Sounds like the ignition switch is working. If the voltmeter is taking it’s reading off the ACC circuit, it would drop to zero when the key goes to START.

 

[4xfun]

Have you looked at the ground between the engine and battery? Bad grounds can cause erratic issues. Over time the ground wire will corrode in the housings. When it gets bad, you can bend the cable and hear it crack. I would check the connections to make sure that they are clean. While you are at it, check the rest of the body ground connections. You may need to add a body ground. See this post:

Where are teh electrical ground locations from factory?

I assume there was: Ground to body Ground to frame ground to motor motor to frame? This thing is all jacked up... That engine ground is going to a water pump bolt.....

classicbroncos.com

I think I have seen several posts about a wire connecting behind the starter relay, but I don't remember what it was used for.

This one is probably a stupid question, when you replaced the starter relay did you connect the wires using the new diagram that came with the starter. The original starter is wired differently and with the new starter, you are using the relay as a trigger. See this post for a better description and diagram

Help with wiring the Mean-Green Starter!

All & this is focused at RRAAAAYYY also!!!! Ok, I have a Mean-Green starter. I can't figure out how to electrically separate the starter from the starter solenoid! There are only two wires external to the two units! Here is the first, that I refer to as the "jumper", though I am not sure...

classicbroncos.com

 

[Madgyver]

independent ground cable connection locked in, Battery neg to starter bolt. If it continues then it could be a bad relay and/or starter.

 

[lewain]

I had this same problem a few years ago. Had me pulling my hair out.
I ended up putting a new battery in with top and side posts on it. I grounded directly from battery to engine block and then directly from battery to a multi post
block mounted on my fender well. Both of theses were #4 copper cables. From my multi post block I ran grounds to dash, and frame.
Problem went away.