This 7.3 Powerstroke starter upgrade I discovered on Amazon will turn your diesel engine over like a 300 pound gorilla!
After upgrading to this high torque starter, the first time I cranked over my 2002 Ford F250 Powerstroke I thought it was going to break something.
Yes, it was that much more powerful than the stock starter!
There are several reasons that your 7.3 Powerstroke may have trouble starting or fail to start at all. Believe me, I chased batteries, cables, and fuel delivery before finally figuring out that my 2002 F250 7.3 Diesel's starter was simply worn out.
And all that was after 2 replaced batteries (though they were weak/dead as well) and the auto parts store swearing up and down that there was nothing wrong with my starter ... after they bench tested it and passed it as good.
After twenty years and a couple hundred thousand miles, your starter will most likely develop problems.
The trouble is, a host of other common 7.3 problems can cause the same symptoms as a weak or dead 7.3 starter.
One telltale sign of a bad 7.3 starter is that the cranking speed will start out okay but progressively slow until it almost stops.
One quick way to tell if your starter is weak or dead is to remove it and take it into your local auto parts store and have them bench test it. I'm not the best guy in the world with a multimeter, so this is my 7.3 starter test of choice—take it to your local auto parts store.
Careful though, mine tested fine at the auto parts store but was dead nonetheless. I read several other forum posts where this exact thing happened to other 7.3 Powerstroke owners.
We're a little bit ahead of ourselves though...
First, let's identify the 3 main parts of your 7.3 Powerstroke "starter."
1 - 7.3 Starter Motor Assembly - This is the big mechanical part of the starter that actually physically cranks the flywheel. And it's located right behind the frame crossmember under the vehicle on the passenger side.
2 - 7.3 Powerstroke Starter Solenoid - this is attached to the 7.3 starter and is the electrical component of the starter. It supplies the juice to actuate the piston so the starter can engage the flywheel gears.
3 - 7.3 Starter Relay - This is a relay generally mounted inside the engine compartment on the passenger fender. The starter relay provides a high current voltage source to the starter. It's main function is to control a high current supply via a low current circuit.
Before 2002, the 7.3 Powerstroke starter relay was a traditional bulky electrical relay with screw terminals to attach physical wires to it.
Part Number: SW-1951C (eBay Link)
This is a video of a Ford F150, but it has a great look at the location of the 7.3 Powerstroke starter relay wiring and its location on the inside of the engine bay, passenger-side fender. Also, there's some good explanations around troubleshooting a bad relay.
The 2002 and after 7.3 starter relay looks more like a big black fuse than the round terminal-looking relay of previous model years.
There were a lot of electrical changes after the 2001 model year 7.3 Ford Diesels. Moving the fender mounted starter relay was one of them. The central junction box—dash fuse panel—now houses the starter relay for the 2002 and 2003 7.3 Powerstroke starter.
Careful—many people use the terms starter "relay" and "solenoid" interchangeably. They aren't the same thing.
In electrical terms, the 7.3 starter relay is an on/off switch detailed above, whereas a 7.3 starter solenoid is an electrically controlled device that activates a piston and is technically part of the 7.3 starter assembly.
This solenoid is mounted on top of the 7.3 starter. The 7.3 Powerstroke's starter solenoid is used to activate the starter's bendix drive causing it to engage with the flywheel teeth and turn over the engine. (see diagram above)
Though the particular 7.3 starter upgrade I recommend in this article may indeed be the best replacement starter for your ailing 7.3 Powerstroke's tired old starter, it's not without its annoyances...
There are two "challenging" things you'll find when you go to replace your OEM 7.3 starter.
One - This 7.3 starter replacement upgrade is much bigger—almost twice the size of your OEM starter. And that's a good thing, but some F250 7.3 Powerstroke year models require that you use a metal grinder and grind down about 1/8" off the cross member. Otherwise, in order to get this 7.3 starter upgrade to fit between the cross beam and the starter socket.
Yep, I said grinding the frame! I did it—sparks and all—and though it wasn't what you might consider an easy install, it wasn't that bad. And afterward, this new high torque starter slipped right into position.
The second annoyance I encountered was that the 7.3 starter ground screw that comes with this new high torque model is so tiny that it can be maddening to get it connected to your 7.3 starter's ground terminal once the starter's mounted. Add to this the fact that you'll be screwing the 7.3 starter ground screw in blind and by feel...
HINT: I turned the ground screw and the circular electrical lead that it goes through around and connected them from the opposite side of the starter ground screw hole. Worked like a charm.
Oh, and whereas your factory starter may have been mounted with three 7.3 Powerstroke starter bolts, this starter attaches with two—there's a metal blank over the third starter bolt hole. (see image)
After grinding a little off of the crossmember to get the right clearance from the mounting position to the frame, it fit pretty well.
Looking to crank your engine over no matter what, this starter isn't fooling around! You can get one for your 7.3 Powerstroke by clicking the image or the button below.
I guess I could list out all the 7.3 starter removal steps... But once again, FordTechMakuloco on YouTube does an excellent job of detailing how to remove your 7.3 starter. Enjoy...
7.3 Denso Starter Part Number - 228000-8420, TG228000-8420
7.3 OEM Part Number - PP17802N
7.3 Powerstroke Starter Upgrade Part Number (DB Electric) - SND0355
If the 7.3 starter above isn't to your liking, or if you just prefer shopping on eBay, this 7.3 Powerstroke high torque starter below is a great option. It's Denso-designed and delivers a whopping 5.5HP. As long as your batteries are good, you shouldn't have any trouble cranking your diesel engine over ... even in bitter cold winter weather.
Whichever one you choose, both of the above 7.3 starters take 2 bolts instead of the stock starter's 3—the third hole's blanked on these starters. If you find one you like with the third bolt, be advised, that third bolt is a bear to get installed. Use a socket extension and have some knuckle bandages ready...
17-21 lb/ft, 22-28 Nm
There it is, pretty much everything you need to know about upgrading/replacing your 7.3 Powerstroke's stock starter with a high torque one that'll crank your big diesel engine over ... hard.
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