glow plug readings dont make sence???

[cman962]

I am having cold start problems. I replaced the bad GPR with heavy duty stancor relay. Still wont start unless plugged in. New GPR is on for about 90 seconds. I am about to replace all the GP's. I decided to check the Glow plugs today with an ohm meter and got full continuity (like touching my probes together) between my ground and all 8 of the glow plug terminals in the UVCH. This indicates to me that they are all shorted out internally. I would assume that a bad GP would have no continuity (open circuit) to the ground. Does this make sence to anyone? Do they burn out and make contact internally sometimes?
Thanks

[greasyF250]

Open circuit means they're shot. I highly doubt that they all could be bad. They will usually last 50k-70k miles, then only 1 or 2 would be bad. If they're all bad , maybe a gpr that didn't shut them off after the usual time, burning them out.

[cman962]

GreasyF250 ... All of my GP's test closed circuit to the ground not open.

I have had a history with cold start problems. Last fall it wouldn't start when temps got below 50 degrees. I found a bad GPR was the problem replaced it with a NAPA relay and all was good until this fall when temps dropped. Same thing GPR tested bad. Replaced GPR with HD Stancor for more permanent fix. This time it looks like I have GP problems because the new GPR tests great... holds power on GP's for over 1 1/2 mins. Still won't start. Belches white smoke. GP test results don't make sence to me. I am retesting today to varify. It's kind of hard to screw that check up though....

[greasyF250]

If you test your glow plugs and get 0 on the scale (like touching the 2 probes together), your glow plugs are shot. If not you will get an ohm reading. I hope I'm reading your post correctly.

[greasyF250]

I maybe off on my terminology, bottom line if the GP's are good , they will show a resistance value, a high resistance would be just as bad . I'm thinking 2-4 ohms are in the acceptable range.

[cman962]

Thanks GreasyF250 .... that is what i was thinking. I had it in my head that there would be no resistance at all, like and open circuit, when the GP's are bad.
FYI my truck has 202,XXX miles on it. I bought it used with 198,XXX on it. It came out of Arizona (NO RUST!!). Anyway I have no idea how long these GP's have been in the engine. I don't think all of them worked last winter. It really missed until it ran for awhile and warmed up.
Thanks for the reply!