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Glow Plug Relay, again?

C

cz_699

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Monticello, IN
I bought my 94 k2500LD last fall, and I'm getting ready to put my second glow plug relay in it. Is this a common item to go out? I put new AC Delco glow plugs in it last fall at the same time as the relay, and new injectors this past Sunday. I will look for a burned wire or connector shorting out the glow plugs first, but I'm pretty sure I routed everything away from the exhaust after doing the injectors. I'm not even getting a Glow plug light at warm starts, and maybe half a second on cold starts.
 
Welcome to TTS.
DO NOT use starting fluid, plug it in or use a hair drier if you have to to start if needed for work until you can fix it. Many a dead idi diesel engines out there from that.

Not a common problem, usually 100,000 mile item. What brand did you buy? I would bench test the controller before buying another one.

Don't just check- take the time to remove your grounds and clean them, faulty grounds are a common problem.
Did you put in 60g glow plugs? Folks on this site are the best around, trust their expertise.
 
It's a bwd. Not the best brand, but what I could get locally at the time. Glow plugs are 60g. All are lifetime warranty from the local Napa. So I'm not really out much if I swap them out. Just checked wires to all the glow plugs and nothing is burnt or broken. I did have to ford some decently deep water two nights ago due to a flooded road, but it started fine until this morning. It started after sitting for twelve hours overnight, but it really didn't want to. Lots of white and black smoke.
 
Water and electronics do not mix.

Check for a wet air filter.

Yours should not matter: BWD isn't the same as the factory unit. It's operation on my 1993 is different from factory GM parts allowing it to reglow the plugs after key on - off. Factory wouldn't allow that.
Your 1994 is ECM controlled glow plugs. So check the Coolant temp sensor, glow plug connector, terminals on the relay, and the ground by the trans dipstick.

Check the ECM for codes.

Duraterms heat faster than 60g's. I have torched 60g's to burned off nubs. Controllers and GP systems are NOT 100K items! They do not usually last that long. Swelling and other failures plagued the 6.2's/6.5's as well as other IDI engines. The 1988 controllers would vibrate a cap off the board and fail under 36K warranty. Reliability is why they invented the self limiting plug and there is no update for 60G's for the extra time they need to heat for any 6.5. Tunes can fix some and resistor mods fix 1993 and older controllers as far as adding glow time.

Hot no glowplug is normal but flaky as far as predictable operation or not at best.
 
If you get into deep water, it may be the starter that gives up, it is way down there.

Load test the batteries one at a time first.

There may be some fuses blown also.

Just a thought.
 
Grounds were clean, batteries are matched and less than three months old. Pulled the relay today and it was full of fuel. I think when I drained the air from the filter housing after changing the injectors it somehow got into the relay. I'm going to keep an eye on it but the old one definitely needed replacement even if it doesn't turn out to be the cause of my issues.
 
You may still want to load test the batteries, unless the flood happens before you change the batteries.

They can get shorted also and you think you have 2 good batteries but only 1 or 0.

Never said that it is only xx month old so I would not test it???
You will be shooting yourself in the foot after you tear down the engine and found out that it is only the battery.
Don't ask how I know. LOL!!!
 
X2, new parts are not always good parts. Never hurts to test batteries. Cranking speed is critical.

Hopefully this solved your issue. The relays should be sealed so it getting fuel or water in it is a bad thing.
 
Not to hijack his thread but my truck is at over 130,000 and original controller, I only owned 2 other 6.5 trucks for extended periods of time and had similar results. Even fording water my Hummer goes complete engine including controller under water on a quarterly basis. Even the donor engine I bought from the 99 van the seller told me he replaced the controller back at 110,000 miles so it probably woudn't be good much longer.
Working in fleets with multiples of these trucks I have only changed maybe 3 controllers over the years.
Am I just running lucky on these? Could it be the extended glow times is shortening the life or possibly the ac delco just last longer?
WW not trying to argue just trying to show a different result than yours. I believe you have most likely put on a ton more mile to these rigs than I have.
 
I will make sure I check the batteries this weekend, but so far its starting better than it ever has. I thought the relay was suppose to be sealed, but when I pulled the old one it was definitely full of fuel. I turned it upside down and it started to run out the seam where the connector plugged in. The new relay doesn't even have a seam in the same area. It looked to be a parting line from when the relay was made, perhaps a short in the molding process. ( I work in plastics so stuff like that always bothers me...)
 
I think fleet use is easier on the starting system than commuter use. Engines are hot all day and run all day vs. 2-4 cold starts per day. I find the controllers although appear to be working slowly reduce glow time with age. I compared two of them (1993) and one kept the plugs red with afterglow and the other did not get a red glow due to different on times. The 94+ are computer controlled and a simple relay - Way more reliable than the older ones.

The relay should have been sealed and not flooded with fuel/coolant etc. Must have ate the RV silicone at the base or had a crack?
 
My experience with the aftermarket glow plug relays has been they're just not as durable as what GM put on them originally.

With a little lower compression than stock, I use extended glow plug time when it gets below ~ 32 degrees. When I built the engine, I replaced the truck's (quite possibly original) glow plug relay with a new aftermarket part. Not quite a year later it was no longer activating the plugs reliably. Vendor honored their warranty & I put another of the same brand on. Again started off working fine, but right around a year later, it wasn't right.

So for the time being, I swapped the old AC/Delco back on & things working again. My guess would be the aftermarket glow plug relays contacts just aren't as heavy as the OEM AC/Delco's.

I've got a new AC/Delco part & PT wiring's glow plug harness on the shelf to go on this summer. Hope the new AC/Delco I have was made to the same standards as the original part.
 
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