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PMGR Starter wiring

guidoverduci

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Mar 8, 2012
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I bought a new PMGR Starter from WH before realizing I already had an older motorcraft one. The older motorcraft PMGR one was hooked up with the battery cable and starter cable on opposite sides of the starter relay/solenoid, but the instructions with the new starter have them on the same side. I‘m gonna do some digging on how these things actually work, but was curious why it worked fine one way and the instructions are suggesting to install a different way.
 
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guidoverduci

Sr. Member
Joined
Mar 8, 2012
Messages
719
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NorCal
Post pics of the current configuration, and study this diagram:

(click this text)
That confirms the WH instructions, but still no idea why it worked the other way. Here’s a pic of how it was wired. The heavy gauge wire that ran down to the starter is not currently hooked up, but it was on the opposite side of the battery. Oh.. and that black wire is still a mystery, started a thread on that one earlier. Consensus was to remove it, I don’t have a coil. But it was hooked to something prior to tearing everything apart.
 

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Ovalis

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The reason for the new wiring configuration is because the relay has basically been moved and attached to the starter itself.
 
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guidoverduci

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The reason for the new wiring configuration is because the relay has basically been moved and attached to the starter itself.
My old starter looked the same though…
 

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Ovalis

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Not sure but I got my starter about 2 years ago and the instructions were to wire it up and you described.
 

DirtDonk

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Yours probably worked due to happenstance and luck. When we first started using them most wired it up as you had it previously and they worked just fine. However enough of them had a starter run-on issue after install and so had to wire it like you have it now.
As long as it works this way, leave it this way.

The black wire went to your ignition coil, OR some other device that needed a START signal while the starter was cranking.
How is it you don't have a coil?

But yes, remove it because if you don't it's just 12v hanging out in space every time you hit the START switch, while just waiting for the worst possible moment to either catch on something or short on something.
Take it off...

Paul
 
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guidoverduci

Sr. Member
Joined
Mar 8, 2012
Messages
719
Loc.
NorCal
Yours probably worked due to happenstance and luck. When we first started using them most wired it up as you had it previously and they worked just fine. However enough of them had a starter run-on issue after install and so had to wire it like you have it now.
As long as it works this way, leave it this way.

The black wire went to your ignition coil, OR some other device that needed a START signal while the starter was cranking.
How is it you don't have a coil?

But yes, remove it because if you don't it's just 12v hanging out in space every time you hit the START switch, while just waiting for the worst possible moment to either catch on something or short on something.
Take it off...

Paul
Thanks Paul (and everyone else!). I wired it per the WH instructions, and I did remove the black wire. I can’t start it yet cause I’m finishing up a D20 install, but I did turn the key briefly, it cranked, and everything seems normal.

I don’t have a coil, there’s a ford HEI setup.

On a side note, there’s a wire within the Painless harness (not sure if it was custom / added later), and it runs down the passenger side. The PO put a female banana plug on the end and it has a constant 12V, even with the key off. Any idea what this could be for?
 

EPB72

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Thanks Paul (and everyone else!). I wired it per the WH instructions, and I did remove the black wire. I can’t start it yet cause I’m finishing up a D20 install, but I did turn the key briefly, it cranked, and everything seems normal.

I don’t have a coil, there’s a ford HEI setup.

On a side note, there’s a wire within the Painless harness (not sure if it was custom / added later), and it runs down the passenger side. The PO put a female banana plug on the end and it has a constant 12V, even with the key off. Any idea what this could be for?
But you do have a coil :)....It's just mounted in the distributor cap....so by saying you dont have a coil can add a little confusion ,

As for possible added/abandon wires that happens all the time all makes and years not just broncos,,and painless harnesses have added circuits so a PIC..?
 
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guidoverduci

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Joined
Mar 8, 2012
Messages
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Loc.
NorCal
But you do have a coil :)....It's just mounted in the distributor cap....so by saying you dont have a coil can add a little confusion ,

As for possible added/abandon wires that happens all the time all makes and years not just broncos,,and painless harnesses have added circuits so a PIC..?
Doh.. good point. :)

Here’s a pic of my mysterious power source… I trimmed back the rubber, but originally it appeared to be a constant 12v source that something was plugged into.
 

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jamesroney

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Yours probably worked due to happenstance and luck. When we first started using them most wired it up as you had it previously and they worked just fine. However enough of them had a starter run-on issue after install and so had to wire it like you have it now.
As long as it works this way, leave it this way.

The black wire went to your ignition coil, OR some other device that needed a START signal while the starter was cranking.
How is it you don't have a coil?

But yes, remove it because if you don't it's just 12v hanging out in space every time you hit the START switch, while just waiting for the worst possible moment to either catch on something or short on something.
Take it off...

Paul
It's just a different way to isolate power on the PMGR starter. You have to have a way to isolate the armature from the S terminal on the starter. If you use the Ford relay to interrupt the Armature current, you need a way to energize the starter solenoid that is not directly connected to the armature. If you tie the Solenoid terminal to the Armature, then when the starter unwinds...the starter becomes a generator, and the counter EMF puts 12V on the armature. That forces 12V on the Solenoid terminal, and the solenoid hangs in and keeps the bendix stuck in the ring gear for an uncomfortable length of time. It grinds like crazy, and sounds horrible until the armature slows coasts to a stop.

So you can put the PMGR starter cable on the load side of the relay, and you can energize the PMGR solenoid using the I terminal on the Ford Relay. But the I terminal was never intended to carry that much load. So you should always wire it just like the instructions say in the Wild H. paperwork.
 
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