ive been having trouble starting my truck on days below 60 degrees, so im thinking its the glow plugs. using a test light i checked the gpr posts and they checked out fine. i pulled the valve covers to check the glow plugs and double check the gpr. i unhooked all the glow plug connectors and used the test light on the connectors to make sure they were getting power. 1 of them was not. that wont keep it from starting, but id still like all 8 of my glow plugs to be getting power. each plug that goes into the valve cover has 5 wires on it except for the one that has the gp connector that doesnt work. it has 5 wires that are going into the plug and then a 6th wire that is bare and is a loop. its the only one that has this extra wire, unless the others are just farther up in the harness. http://www.ford-trucks.com/forums/al...pictureid=2864

is this wire supposed to be there or hooked up to anything? also, i need to check the ohms on the glow plugs, but im not sure what setting to put my meter on. is has a 2000k, 200k, 20k, 2000 and 200 setting. any ideas there?

 

Set meter to lowest resistance scale, 200 ohms in your case.

No, someone rewired that harness, not good. I can't tell from the photo but you might have to start removing the tape back from there to find out where the connections are.

I just hate shoddy fixes ... makes it really hard for next owner to make proper repairs.

 

That looped wire is supposed to be like that. Its a shielding wire that goes all the way back to ground at the IDM. The whole harness is wrapped in heavy tin foil and uses that wire to keep electrical interference in the harness from the injector wires.

As for testing the GP's use the lower scale like Jim said. A good GP should measure 20 ohm or below. preferably 5 ohms or lower.

 

IF I UNDERSTAND RIGHT YOU CHECKED THE GPR WITH A TEST LIGHT, I AM NEW AT THIS BUT I THINK YOU SHOULD CHECK IT WITH A METER TO MAKE SURE YOU HAVE ENOUGH VOLTAGE. jIM

 

below 60 F??

 

yes, i checked the gpr with a test light. thats how youre supposed to check the gpr. you check the glow plugs with the ohm meter. i said i checked the glow plugs with a test light first just to make sure they are getting power in the first place. to eliminate a wiring problem or plug problem in between the gpr and glow plugs.

 

yeah, itll start on the first try every time when its about 50 or 60 degrees. anything colder than that and it wont start at all. i havent checked the gp with my ohm meter yet, but everything else has checked out good so far.

 

A good GP will ohm out to .8-1.2 ohm. A bad one typically (but not always) ohms out to 50-60 ohms. To test your GPR, turn on the key and test for voltage across the big wire connections on the top. Any voltage drop through the relay will show up. Voltage should be zero. I only replaced the bad ones and got away with it so far. You can get an entire set of ZD-11s on ebay for around 50-60. Rockauto.com sells them for 10.45 a piece. My local Ford stealer wanted 25.94 a piece.

If the relay is indeed the culprit, I hear the Stancor is a good choice.

Aaron

 

Aaron when I tested my relay it reads 12 volts when the key is off than drops off to zero when I turn the key on and then back to 12 volts after about 2 minutes. Is my relay working right?

Thanks

Pat

 

when your checking the relay check resistance between terminal 85 and 86 should be 40-80 ohms then check resistance of terminal 30 and 87a which i believe is the normally closed position (check the image on the realy and make sure) there should be some sort of resistance there to show there is contact being made.(most of the time its very small)
then check the resistance of 30 and 87 to make sure there is no contact made cause thats were the pole moves over when the relay is energized, then energize the relay by putting power to the 85 and 86 terminals and check resistance again of 30 and 87 and make sure the pole actually moved over (even if you hear the click) and check 30 and
87a one more time to make sure there is no resistance ( or open)

if all this checks out the relay is perfect!

 

thanks for the info. ive got a friend at my ford dealer that gives me everything at cost, which would be around 11 dollars each. i pulled one of them out last night and it was some brand made in germany. started with a B i think. so that tells me theyve been replaced at some point already.

 

Beru is the brand and that is the factory motorcraft

 

yeah, thats it. so now that tells me that they havent been replaced lol. at 190k miles id say its about ready for a new set anyways.

 

My Beru's (Motorcraft) were made in Ireland. What you saw was the voltage drop due to closing the contacts and the extreme low resistance in the glow plug circuit. It sounds normal.

It sounds like you are replacing the set so you should nail the problem.

Aaron

 

i checked the glow plugs with my ohm meter last night and got absolutely nothing. i cycled the plugs on several times and checked every plug and the meter never even moved. i pulled all the plugs out and every one of them had a ton of build up on them. 3 or 4 of them were covered in oil and the rest were completely dry. not sure if thats normal or not......