1972 Bronco Starter Does Nothing.

[Ark Bigfoot]

It was cold (12 degrees) thought I would start up my truck and Bronco and let them idle to warm up. The starter turned it over very slow 3-4 seconds which I would tried the short burts several times. Then it was just the solenoid click which I thought was a dead battery. I put the 2yr battery on charger and charged to 12.6 overnight. I put an ohms meter on the output post of the solenoid and recorded the reading with my phone. I get .16 volts with the key on and 11.96 volts when trying to start. It has warmed up to 42 degrees today and the starter does not do anything just the solenoid click. I have not checked the connection to the starter.Is this an indication of a bad starter?

 

[B RON CO]

Hi, my first guess is the battery. Can you try with a battery you know is good? Or jumper cables. I would test the battery before buying anything. Good luck

 

[Ark Bigfoot]

I tried the battery charger which has a engine start mode and it did nothing. Will try jumper cables after it stops raining.

 

[DirtDonk]

where are you measuring voltage? And on matter where it is, .16v is not enough to do anything normal on a 12v vehicle.

When the key is ON there should be no voltage at either of the small terminals, or the starter side of the large terminals on the starter relay. Only the battery side should have battery voltage.
Where are you measuring?

And when you turn the key to START, what voltage reading do you get on the Red w/blue wire on the "S" terminal?

Paul

 

[Jebus]

I would turn the key off and rotate the engine a bit by hand to see if the bendix is stuck and engaged to the flywheel.

 

[DirtDonk]

I forgot to mention that the 11.96v reading when the key was in START is indicating that the starting system is not even trying to start. If it was the battery voltage would be much lower I believe.

So test for 12v at the Red w/blue wire when the key is in START and go from there.

Paul

 

[Ark Bigfoot]

The Red/Blue left Solenoid terminal show .007 with the key on... https://www.flickr.com/photos/77159845@N07/50966450998/in/dateposted-public/ The small right terminal on solenoid shows 8.48 with the key on.....https://www.flickr.com/photos/77159845@N07/50966463003/in/dateposted-public/ The Main power coming in to the Solenoid on the left is the same as the battery 11.96 and with the starter engauged it is 11.96. With the key off the only power is to the Power terminal in the left all others are .007. The power is coming in from the left to the solenoid on the picture and goes to the starter from the right side.

 

[DirtDonk]

Strange little readings, but i would say first off that the 11.96 is a dead battery and you're not going to get much joy out of that one until it's fully charged and holding the charge.
The lower reading at the Brown "I" wire terminal is consistent though. So the ignitions switch to ignition coil circuit seems intact. But that does not effect cranking anyway. Just the starting part.

Get another known-good battery in there to see if anything changes. And if not, re-check the voltage at the Red w/blue wire terminal with the key in START.
Check the tightness and cleanliness of all of your main cables as well.

Paul

 

[Ark Bigfoot]

I checked the Red/Blue when doing a start and it reads 11.89. The Battery was bought in March 2019 at Walmart so I will take it back. Has a 750 Cold Crank amp which if good would have been enough.

 

[DirtDonk]

Yeah, more than good enough if it was up to snuff. And while just under 12v "should" be enough to crank the starter weakly, it's generally considered way down on the charge list when you read what the battery companies say. Something like 12.6 is fully charged, but 12.1 is like 80% discharged! Or something like that. I don't remember, but the specifics have been posted up a few times over the years.

That said, the same 11.8 should be more than enough to get a good click out of the starter relay. Which I think you said it does? So it seems consistent with low voltage.

And this is the time of year when borderline batteries die an ugly death. When it's super cold they struggle unless they're in tip top shape. Maybe yours is borderline, but it's good you found out now rather than far away from home.

Good luck. Hopefully they give you some credit for a new one, or however that works these days.

Paul

 

[Ark Bigfoot]

I put it in gear and pulled it about 2 feet with my truck to perhaps make something happen at the starter. Still nothing. I took the battery to Walmart and they did a stress test and rated 12.3. I am going to crawl under and tap the connection with a hammer at the starter and then try again to see if anything happens. Could be a faulty starter connection. If not I will take the starter off and try adding 12 volts at the bench. Doesn't look difficult to remove. Only two bolts and disconnect the 12 cable from the Solenoid. I see where they now have a Mini-Starter are those a reliable starter? Is there anything I need to do to make installation easier?

 

[DirtDonk]

Yep, just the two bolts. One is always a bit awkward, but it's gettable.
If you try the starter on the bench (or on the ground like most of us likely do it) be sure to put a good heavy foot on top of it before you hook up the jumper cables. It'll jump right out of it's skin if you hook it to power just sitting there on it's own.

The modern starters are just as reliable (or unreliable if you get a bad one) as the old ones. Use less energy, smaller package makes it easier to hoist up there and install, stays further away from header heat, but nothing wrong with the old design either. Up to you.
Lots of us have changed to the modern "mini" or PMGR (permanent magnet, gear reduction) style starters. Use a '95 pickup/Bronco as your donor of choice, choosing only by the type of transmission you have. Manual and auto transmissions take different starters.

Maybe yours is fine though. Lots of battery and starter cables failing these days. Just gettin' old in most cases.

Paul

 

[Ark Bigfoot]

You were correct Paul the connection at the starter needed to be replaced but it was still a bad starter. I hooked the old one up on the driveway and sparks flew. The armature stuck to the side. Put in a new one, which was still under life time warranty(19years), and it started right up. Thanks for your usual expert advise.

 

[Daniel1986]

I used Truck Pac ES6000 jump starter for emergency use. I have a 6 month old battery that died on me while I'm on a 2 day road trip. I always bring it during long driving. It spared me the hassle of getting help, especially it happened at night. Luckily I read an article https://motoringcrunch.com/reviews/truck-pac-es6000/

 

[DirtDonk]

Nice unit. Glad it helped you out of a potential bind.
Shame you have to carry one of course, but nice that you have it and don't have to have that other experience instead!

Paul