7.3 glow plug relay conversion to gpcm.

[David_V]

I have read a post from 2008 about how costly this could be on a 2002 f350, but I am curious to see if any else has thought about if it is possible with only minor changes, like if the PCM is the same, it looks as if the harness can be modified to accept the gpcm. The reason I want to do this is the reliability of it, I have replaced lots of relays and getting tired of it, any help would be appreciated.

[DwayneGorniak]

This may be more reliable yet: http://www.wiringproducts.com/contents/en-us/p919.html Just mount that puppy right on your dash.

 

 

 

Not a bad idea though. I have thaought about the very same idea myself, But I really don't have many issues with my relay. I have only had to replace mine once in the last five years. Are your glow lug resistances within spec?

[DieselD]

yeah I have replaced way more gpcm modules then the simple relay setup

[joshbuys]

7.3L built to meet California emissions were equipped with the same GPCM that was used on the 6.0L and 6.4L. from the factory. I don't know what modifications would have to be made to the harness, or if you'd be better off getting a Cal. emissions harness, there is a bracket for it to mount on, and I would guess you just need to reprogram the PCM, perhaps using the VIN for a California truck?

 

We do replace a ton of modules on them out here, even though it doesn't usually get cold enough to need them here, it does set that pesky orange light on the dash.

[David_V]

My resistances are all 1.2ohms, which is in spec, i have replaced 3 allready this year, took them apart and signs of bad arcing inside, maybe it was just a bad batch of relays

[Bruce Amacker]

First off, forget resistance checking GP's, only use amp draw. It's not only correct but much quicker. They should be 190ish for both banks and 25ish individually.

 

IIRC the original relays were nitrogen filled to prevent excessive arcing. The aftermarket relays were 1/5 the price but probably not nitrogen filled (IIRC $15 vs $75). FMC might have gone to a cheaper (offshore) supplier.

 

[Keith Browning]

First off, forget resistance checking GP's, only use amp draw. It's not only correct but much quicker. They should be 190ish for both banks and 25ish individually.

 

Ever since you taught me that I wanted to do an article on it. Must remember to snap some pics the next time I diag an older truck.