7.3L Power Stroke Engine and DrivetrainDiscussion of the 7.3L Power Stroke diesel engine and drivetrain in the 1999-Up Super Duty trucks and Excursions. No gas engine discussion allowed except on transmissions and drivetrain that pertain to all models. Please confine discussion of topics in this forum to those items that are specific to the 7.3L Power Stroke engine.
Posted this in the other thread but its kind of buried deep, so figured would start a new thread...
I purchased a MR99 GPR from Autozone ($13.99) and it is identical to the current GPR except that the terminals are all clocked 90 degrees off.
My question is, does it matter which of the two large terminals I hook the large wires to, and also does it matter which of the 2 small terminals I hook the small wires to?
The small terminals are labeled "i" and "s" (ignition and start), but the original doesn't have those.
Do I have a 50/50 chance here? or will I be taking it back along with the wrong fuel filter/water seperator?
Thanks!
Randy
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2001 F350 Lariat PSD, 4x4, 4DR CC SB, purchased 2/27/07. Edge EZ Chip, Ford AIS intake with Fender Sleeve (added 4/2/07), ZooDad mod (7/14/07), Pillar Gauges (ISSPRO) EGT, Trans Temp and Boost (added 3/21/07), Dynomax 4" turbo back exhaust (added 3/9/07), 2 inch leveling kit, 35" BFG's, Huskyliner floor mats, Rear Airbags, TopDeck Tonneau Cover (added 4/3/07), Excursion "Hush Panels" under the dashboard. Forged Rods! (Factory!)
I have posted regarding the MR99 before, I do not know if they use the same molds to make the GPR and starter relay, or if they are the same starter relays. I do not have an Autozone near me to test one, so with S & I I am assuming it is a starter relay. Heres a copy of my earlier post on that relay.
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It does not matter what wire goes on which side on the big lugs, but if it says S & I on the small terminals, it does matter, or you will possibly cook some components. Normally, power is sent to the S terminal, which then energized the relay and applys power to the other big terminal, as well as the I terminal, which is used to send full 12volts to the ignition coil on gassers. The base is used to ground the relay on those.
Also, the glow plug system on the PSD applies a constant power to the relay through the red/lt green wire and the PCM controls the ground through the Pink/Org wire. So if you hooked up the relay with Rd/LG to S and P/O to I, you would always have the relay energized, and also send a full 12 volts into a PCM output circuit, can you say burned up PCM?? Hook it up the other way around and the relay will never energize. I would make dang sure that is the right one, not misboxed or anything. If in doubt, I would buy one from a different vendor.
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To check if it is a GPR or a starter relay, if you have a multimeter check resistance between the S and I terminals. If it is open, it is a starter relay, and if it shows (IIRC) less than 10 ohms, it is a GPR.
Buddy
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Former Ford Diesel Tech
ASE Certified Parts Counterperson, Automotive, Medium, & Heavy Truck Technician
1999 F250 XLT 4x4, Red, 7.3 6spd AWA5, 3.73LS rear, CCV Mod, APC Headlamps, Autometer C2 Gauges, (Boost,Pyro,Trans), 4" Turbo-back exhaust, XM Radio, AIS, ITP Regulated return, fuel feed lines, Airdog, & 4pos. chip. My Truck
2001 Ford Escort ZX2 - Black- 4cyl 2.0DOHC, 5spd.
1999 F350 4x4 XLT, CC/LB PSD, 6spd, Aluminum service bed, York Compressor Onboard air, CCV, Custom Intake & Exhaust, Strobes and a few other goodies
RIP Steph F. & Trista J., 4/27/07, you will be missed by many.
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