GPR relay and PCM help

[Chad T]

I checked my GPR and plugs and both are fine so it looks as if my PCM is not telling my relay to open. Where do I find the PCM and where do I go from here to get the PCM to get the relay to open? thanks Chad

PS. The OBS doesn't have 9 pins to check glow plugs so which pins do you use? They have maybe 5-6. Thanks Chad

[vitalidle]

How did you test out the relay? Here is a writeup that explains the glow plug test on pre 99's also.7.3 glow plug system diagnosis

[Chad T]

Vitalidle, I check the old one with a meter and got nothing when the switch was on so I replaced it with a new GPR109 from Napa. After getting it on I tested with a meter and still didn't get anything. I did figure it out it was with the GPR 109 the mounting holes are turned 180* so I had the wires backwards and now it opens and closes after 30-60 seconds like it should. The truck calles for a GPR110 ($89) Napa has the same relay just different mounting holes GPR 109 ($28) so I went for $28. Thanks for the help. Chad

[vitalidle]

Good deal! Glad to hear your up and running