When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Changed the flexplate out on my wife's 79 F250, which has a 400 & a C6. Got that done with no real issues. But once I got everything installed again & hit the key, never ending issues.
Hit the key and its a varied mix of different results.
1: nothing happens.
2: starter spins, but the bendix doesnt engage the flexplate.
3: starter cranks & the bendix engages, but it's only for a second.
4: starter cranks & the bendix engages, but then wont disengage.
5: key in run & jump the solenoid & sometimes it's a mix of #2 & #3, sometimes it'll also just fire right up.
I've made new battery cables, new ground straps, added a ground from the starter to the frame just in case, multiple starters both original & newer pmgr that I bench tested myself for proper function, 4 separate solenoids both old and new, multiple different ignitions. Getting the same results no matter what.
I dont know if there is something in the under dash wiring that I'm missing.
I changed the flexplate due to worn out teeth causing a dead spot.
Whenever I have a new problem after I've done something my first suspicion is what I've done has caused it. in your case that's the flex plate and it's installation.
Are you sure it was the exact same flex plate? even minor differences could cause your problem. are you sure it didn't get warped or distorted in installation? were the dowl pins in place so you're sure your transmission is in correct alignment?
I would watch from underneath while someone cranked the engine to verify everything is running true.
GMGR starters are wired differently then stock original Ford starters.
How did you wire it.
If you want help with electrical troubleshooting, you will have to share some electrical information.
Do you have a volt meter?
Do you have a regular test light? Not an LED style, but something that actually draws some current.
The more information you share the better the advice you will get.
Jim
Last edited by JimsRebel; Dec 27, 2025 at 11:31 AM.
GMGR starters are wired differently then stock original Ford starters.
How did you wire it.
If you want help with electrical troubleshooting, you will have to share some electrical information.
Do you have a volt meter?
Do you have a regular test light? Not an LED style, but something that actually draws some current.
The more information you share the better the advice you will get.
Jim
Volt meter
As wired right now.
As the instructions showed.
Ran it this way with this starter for a year and a half until the flexplate ring gear gave up the ghost. This issue where the starter will just bump for a second & then free spin started the day I got the truck moves around to the driveway to pull the engine. I'd notices it, but thought it was the dead spot on the old flexplate.
Feel free to treat me like an idiot when it comes to electrical issues, because I am.
No expert by any means and don't know what I have and what you have, so better wait what the others say.. But my first thought was "Mine is connected on the other side of the relais, not where the battery cable is"
That’s probably because you have a stock style starter that doesn’t have a solenoid mounted on the starter itself. What the OP is showing is a wiring setup for a modern style starter where you basically turn the original Ford solenoid into a relay.
When I went to the Powermaster starter I completely eliminated the factory solenoid and ran the trigger wire from the neutral safety switch to the S terminal on the starter solenoid. However, that might not be possible for the case in question since I have an aftermarket wiring harness, a one wire alternator, and a Pertronix distributor.
Feel free to treat me like an idiot when it comes to electrical issues, because I am.
In the drawing / instructions, the box in the lower corner, that says " don't use a jumper wire...
Well, I though that's what you did, so it just proves your not an idiot. 😁
Yes you wired it correctly, but not everyone does.
I am a fan of PMGR starters, I wouldn't recommend going back to original.
I think the Bendix on the starter has failed. That's the part the moves the gear out and also engages the starter motor internally... when the gear is fully extended.
You need the original fender mounted starter solenoid to handle the "rush in" (or surge) current. Even a 30 amp relay isn't enough. If you try and run this directly off the key switch, something will fail. Most likely the ignition switch.
As you have tried different starter solenoids, all that is left is the starter
As a separate test, power the "S" connection on the starter solenoid, directly from the battery. This will rule out a truck wiring issue.
Jim
Last edited by JimsRebel; Dec 27, 2025 at 03:09 PM.
On a side note, what ignition system are you using?
I am asking because I noticed that you were not using the "I" connection on the starter solenoid.
Jim
That question was on my mind too. I was kinda fishing for information with my earlier post. Alternator type? Ignition system type? He might have some different wiring options depending on what components are in play.
I've had a Power Master starter on here for the last 18 months.
This one.
Granted its not that clean anymore, but was working just fine until the flexplate gave up the ghost. And it's the one that went back on, except for when I tried the factory style and yes I did put the wiring back to factory for that one.
After looking for 3 days I found this one I'd bought for one of the other trucks. Essentially the same as the Power Master unit. It's for 92 f350 with a 460 and I think a zf5 transmission. It was used for maybe a few weeks.
Yup, still no joy. Same issue.
As far as ignition system. In this I'm running a msd 6al box and a msd ready to run distributor. Started using those the same time as I started using the Power Master starter.
And as a "just in case" I made sure I installed the new flexplate the right way, and I did.
What happens when you put 12V directly to the S terminal on the starter? Do the intermittent problems that you described with the bendix engagement occur?
Pull the plug wire from the coil to the distributor cap so the engine doesn’t start and repeatedly jump the S terminal to voltage. See what happens.
Last edited by Viper Pilot; Dec 27, 2025 at 05:22 PM.
Pulled the coil plug and tried from the S lug, same thing.
I've got three parts cabs with complete harnesses in them & a loose cab harness that only had the hi/low switch cut out of it. I'm about ready to swap in another harness & see what happens.
If you applied voltage directly to the S terminal on the starter and the problem remains you do not have a wiring problem, assuming of course that you have a good cable from the battery of adequate gauge.
Is there any chance that the torque converter became unseated when you swapped the flex plate? That would push the ring gear away from the starter. Have you driven the truck since the swap?
Last edited by Viper Pilot; Dec 27, 2025 at 06:12 PM.
Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath
Slideshow: Called the Fortress, the 850-horsepower pickup combines Raptor underpinnings with military-inspired features, survival equipment, and a starting price of $285,000.
