Glow plug change out questions


New member
Howdy folks,
In the spring, I did Dr.A's glow plug test, where you take the plug off the glow plug module and use both the size of the spark and the resistance of the glow plug to determine whether they are OK, open, or shorted. I had one shorted, two open, and two which produced only a small spark ( should be OK), but the resistance reading was .001 ohm, not the target 5 ohm.
I purchased 5 new Bosch glow plugs and the newest replacement module from Europarts SD, and checked out various repair procedure write ups provided by this forum. I liberally soaked the glow plugs several times with Kroil, over several weeks. Now the weather is getting cold, I proceeded to change the glow plugs. 1 to 4 went fairly easily, but were apparently put in "dry" and "screeked" a bit on removal, resulting in the application of more Kroil, which eliminated the noise and made the unscrewing easier. All 4 glow plugs seemed to be about a normal tightness, not seized up. A couple were bound up by carbon, so more Kroil was applied, and the plug rotated in the out direction for maybe 30 seconds by hand, at which point one could pull them out. Kroil is great! Before attempting removal of the glow plugs, I drove the van to the top of our local pass and back, so the head would be fully warmed up, apparently a very important part of the process. I used the special aluminum formulation of never-seize on the new plugs.
Then I got to #5, which is a little farther back than my arms are long, and is buried and even very hard to see. 3x now I've tried to get the electrical connector on top of the plug off, using various combinations of LED lights, long needle nose, a kelly surgical clamp, several different configurations of bent wires, etc. So far, I have not been able to remove it, but will keep trying once this weekend's blast of winter weather passes. I'm off to the solar Pioneer Party in Willet's, Ca the first weekend in NOV, and i'd like the new plugs to function, as it may be cold going and coming back.
So: Dr.A's test produced only a small spark at #5, so it might still be close to working.
My major question is, if I install the new glow plug module, which has a circuit breaker rather than fuses, what are my chances of damaging it with one old, out-of-spec glow plug?
As an electrical type guy, I suspect the CB will save the unit if needed. And it might not even be needed. Anybody got knowledge or even an informed opinion about this situation?
I WILL eventually get the plug off #5 and get it changed. But it looks like it may take a while.
Anyone got a secret method for getting the electrical plug off #5?
Charlie in the Tetons

Goofy foot

sliding left...
I used the hose clamp needle nosed pliers from Harbor Freight to take mine off. Just make sure when you're pulling up you don't stress any other lines or wires. You may need to lever it off. It will come. When it does...I hope it's already been Kroiled. #5 is to be removed most carefully. Make sure your socket is fully down over plug and perpendicular to the head when loosening.
With the new CB module installed it shouldnt be an issue with one bad plug, but you could just tape off the end of the plug on #5 and go on your trip.
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I LIGHTLY ground the retention detents on my connectors so that the next removal is much easier. If fact,and not just MB all electrical connectors seem to be a puzzle that drives me crazy.

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