I have two questions. 1) does it matter what posts I put the two wires on the gpr? I bought a new one and am not sure. both posts are the same diameter. 2) am i an idiot because i bought the gpr-111 because it had the pigtail. Do I not need to hook the pigtail back up? Is this why the gpr-109 works?

 

I can't remember, sorry. When I replaced mine I labeled them. What I'm thinking is that it doesn't matter but this will give you a bump so the experts will chime in.

 

You might find the information you need in this link, there is some very good info.

https://www.ford-trucks.com/forums/4...ke-thread.html

 

It does not matter what wire go on what terminals on the GPR. And if you got the GPR111 with the two small wires in the connector, you can either take that harness off and use your old one (the two small wires) or just disconnect the old harness (assuming it has the connector in it) and plug in the new one.

The only thing that really matters is that you have one wire only on each post. Like this:

 

it won't matter which of the big lugs go to which wires as its just an internal contactor closing the circuit. there might be a directionality to the coil actuated by the two smaller wires, but it won't hurt anything to hook it up backwards and test it out.

hook it up how you think it should go, clip your voltmeter between the big lug that is NOT powered all the time and a good ground (it should read 0V) with the truck off. then, get in and flip the key to RUN, so the wait to start light comes on - but don't start the truck. you should hear the usual GPR click but some units are quieter than others, so maybe not. get back out and check your voltmeter. if its now reading 12V, you're good to go. if not, flip the small wires around and test it again.

 

you beat me to it, Nate. does it not matter which small wire goes where? I was thinking of just a simple coil/magnet-slug solenoid and thought the wont polarity of the small wires could send the magnet-slug in the wrong direction...

 

I guess I can't say for sure, but I know I have never had one that I have had to swap the wires on. So either I'm just darn lucky or it doesn't matter, lol. IIRC there is a connector in the two smaller wires that will let you unhook them both from the truck harness. If that's the case, then the best bet is to just unhook the old harness and plug the new one in.

 

Neither circuit is polarized.

 

well, there you go - it doesn't matter.

my only GPR swap has been to upgrade to the Stancor/White-Rodgers - twice - and it does not come with any attached wires. i did find that the old wires were pretty much frozen in place by the hardened insulation on them. plus there's not much slack in any of them, so it was pretty obviously which ones went where.

 

Thank you all for the information. The new gpr is working but still struggles to start. If plugged in for the night it fires right up. I'm thinking bad glowplugs. Hpop is full and batteries are good (volts drop to about 10.5 while cranking). Truck is a 95 with 63k and nothing has ever been replaced. Any other thoughts would be great. I think I'll do stage 1s if I'm in there.

 

It sounds to me like you need some glow plugs (and some stage 1s too!). If you disconnect the wiring harnesses at the top of the valve ocvers you should be able ot test the glow plugs with a meter. Measure their resistance to a good ground on the engine and you should see no more than about 3 ohms each. The glow plugs are the outside most pins on each connector. Ideally they should measure about 1.5 ohms each, but I'm guessing you will find some that measure to be an open. If that's the case they're shot.

And wow, a '96 with 63k miles on it! That's a rarity these days. Sounds like there should be a lot of life left in it.

 

Measure the resistance of the glow plugs at the UVCH connections. Should be about 1 ohm each. Also check the UVCH connectors.

 

Silly question, but do you meter the GPs with the key on or off? Also, the OHMS setting has the little "u" looking symbol, correct?

 

Key off. Harness unplugged. The ohms setting should be marked with the Greek omega sign.



If there are several ranges on your meter, use the one with the lowest number value.

 

try a slow 20 count after the WTS light goes out, mine won't start on a 40 degree morning without it. Lit off yesterday and it was 27