No crank - trouble shooting

[Roy66]

Okay, here is the story - modified 66 wagon with 302 based 347 stroker; full MSD including box, coil and distributor; new starter and starter relay; battery is optima red top, fully charged, but now new, approximately 8 years old.

All other electrics work, but on turning the key, relay activates but no crank and then everything is dead. I checked battery connections at the terminals - both tight and clean, negative has a quick disconnect.

At this point, I suddenly have power to all electrics again; turn the key, relay activates but again no crank and everything is dead - repeat.

Truck started with this setup a month ago, so what am I missing here? Possibilities - Is it the ignition switch? Is it the battery?

 

[pcf_mark]

If you put 12v to the S terminal on the starter solenoid does the engine crank? That eliminates key, solenoid and most wiring. Any 8 year old battery is on borrowed time.

No chance it has a C4 conversion? The NSS can crap out.

 

[Roy66]

Thanks, yes it has a C4 auto; I will check out the neutral safety, as well as jumping the solenoid to eliminate the key switch.

 

[DirtDonk]

When the power goes out, you mean everything, right? No lights, horn, nothing with the key?
Definitely jump the relay as a test (in park of course!) but yours sounds like a classic buggered battery cable. Even if they look perfectly good.

There are only a few things that can kill power to the interior. The battery cable (either one) or the Black wire from the battery side of the starter relay.
If you jump the relay and it clicks, then all the power dies again, it's 100% guaranteed (ok, maybe 99%) ) to be a battery cable.
In that case, they're cheap, so just buy new ones.

When it happened to me it was a two year old very nice positive cable between the battery and starter relay.

Paul

 

[DirtDonk]

Of course, it's always possible that the old Optima is dying. That would normally not have quite the same symptoms of everything getting cut off and then magically re-connecting. But if it's the main posts degrading, it's possible.

I've never had a battery do that, nor have I heard of it happening. But it seems possible.
I just relegated an 8 year old (now maybe 9) Red Top to the back up mobile, but it's still cranking too, like yours. Compared to the newer AGM that I swapped it for, the new one definitely cranks the starter faster, so it seems like it's getting tired.
But it's sure aging gracefully I'd say!

Good luck. Hopefully it's the relatively inexpensive cables, rather than a way more expensive battery. But you still got your use out of it, in case it turns out to be the old guy.

Paul

 

[Roy66]

Thanks for the great advice - yes, all power goes out when I cycle the key. I was thinking it might be the negative battery post, but your point that it may be the cable is more likely.

I will check out the battery cables and solenoid wiring first, then if still no start, I will suspect the battery. Honestly the optima is due for replacement anyway. Thanks again, and I will report back my findings.

 

[laserfish]

I have had this happen on a car once. Battery worked all the electronics, radio, etc. but as soon as the key was turned...nothing. Then the battery would give enough charge to make the dome light, radio, etc to come back on. Replaced the battery and it started right up. 8 years is a very old battery.

 

[pcf_mark]

Since you have all or nothing it is probably not the solenoid, key switch or related wiring as I was having you test. After replacing the battery I would be suspect of the fuse panel where the power goes from the engine compartment side to the passenger compartment. These get loose and crusty and build up a lot of resistance. Mine was glowing at one point letting me know it was time to clean it.

 

[DirtDonk]

...8 years is a very old battery.

Yep, very old. All of my Red Tops (this is the fourth I believe) have lasted longer, but that's no guarantee they all will. The last three I retired were 11, 10 and 10 years old respectively and still worked.
They were just a bit weaker than they should have been when the weather got cold (like right now in fact;D), so yes, it was time.
Just like in this case perhaps. Better safe than sorry when it comes to batteries.

After replacing the battery I would be suspect of the fuse panel where the power goes from the engine compartment side to the passenger compartment. These get loose and crusty and build up a lot of resistance. Mine was glowing at one point letting me know it was time to clean it.

Yikes! Glowing? That was a wake-up-and-smell-the-burn message for sure. Just prior to real smoke signals!;D
Good advice for anyone owning an old glass fuse type electrical system anyway. That resistance is a real wire-killer.

Was this on a '70 or earlier model Mark? Maybe you're on to something with this, as the two firewall plugs (I wasn't even thinking about them last night) can be another source of circuit-breakage in the main wires. And with the fuse panel right behind (or nearby at least) they all take a beating.
So Roy, is this all basically still stock wiring on your '66? Or have any of the key components of the harness been replaced over the years?

Normally your issue would still be one of the main cables in this case, but don't ignore the big Black and Black w/yellow batter power and alternator charge cables while you're digging into it.
I still think changing the main cables is a safe and inexpensive fix, even if it does not fix this particular issue. Getting new and larger gauge battery cables is a great upgrade if it was not done already.

If it was the fuse box alone however, the ignition and headlight light switches would still have power because they're independent of that section and are spliced directly into the Black power wire. At least they are on later trucks, and I believe that even '66 had the same wire scheme as later models in this area.

Paul

 

[Roy66]

Okay, my bad - I was able to do a bit of investigating after work and before it became dark out there. So the battery (Optima red top) was purchased in mid 2007, according to the markings on the top.

I bought this Bronco in 2010, and the PO said the battery was near new, so 2010 stuck in my mind. But no, it is almost 12 years old (time to replace!), but not necessarily the cause.

Most of the wiring on my 66 is original harnesses, with some mods. I did replace both positive and negative battery cables after I bought the truck, with heavier gauge wires, so that makes them about 8 years old.

So, I will replace the battery (it's time) and cables (inexpensive), to rule them out, then go from there. I really want to thank everyone for their input and advice, and as many have said before, what a great forum!

 

[gnpenning]

It may be time to buy a voltmeter and checking voltage and voltage drop. When replacing parts you don't know if it was the part or the connection. I prefer to know I'm replacing a known bad part.

You don't need a high dollar meter, there are many cheaper ones that will do what you need and are easy to use.

 

[DirtDonk]

Yep, an invaluable tool in the old tool box. A small cheapy too, like a Harbor Freight freebie, is a good one for banging around under the seat or in the tool box.
But a nice $15-$25 version from Sears or wherever (but they're likely to be on sale now!) can be a bit nicer.
Accuracy is a good thing, but even the cheap beaters are going to be close enough for many jobs.

Paul

 

[Roy66]

Okay, found the culprit for the no crank and and complete loss of all power on turning the key - it was the negative battery cable. Replaced it and engine cranks solid on the 12 year old Optima red top.

I am replacing the old battery as well. Thanks to everyone for your help, Regards, Roy.

 

[DirtDonk]

Hey, congrats on the fix.
And thanks for the follow-up with info.

Paul

 

[sprdv1]

Okay, found the culprit for the no crank and and complete loss of all power on turning the key - it was the negative battery cable. Replaced it and engine cranks solid on the 12 year old Optima red top.

I am replacing the old battery as well. Thanks to everyone for your help, Regards, Roy.

Excellent..