Melted Glow Plug Control Module

torahtom

Well-known member
Joined
Jun 24, 2007
Location
Elizabeth, CO
TDI
1996 Passat Sedan, 250K
Connector and plastic box melted on the small Allen bolt and lug in the top right corner of the module where the red hot lead comes in. Took out the control box and used a dremmel bit to remove melted plastic. Lug was about 1 inch away from its hole. Siliconed it back in place. Got so hot it melted the cover and blue out main power relay #109 in fuse box. Tried to start it with a tow but no fuel getting to engine. All lights on dash except the oil and battery light stopped lighting up. No speedometer either. Thought the ECU was fried too. Took out the ECU and inspected it and no burned parts of circuit board. Put ECU back in. Checked battery ground for both positive and negative under the battery. Put a new 109 power relay in and now glow plug and all lights come on on the dash when turning the ignition on.

Does anyone know where else to start looking for a short?

Can the box be reused? Or does anyone have a glow plug control module box. Part # is 191 911 261 b
 
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ToddA1

Top Post Dawg
Joined
Aug 3, 2011
Location
NJ 08002
TDI
'96 B4V, '97 B4 (sold), '97 Jetta (scrapped)
That’s for the coolant GPs, not the engine GPs.

It’s just a mount point, so it can be repaired. Obviously you probably have some resistance in the wire if it melted, so that needs to be addressed.

-Todd
 

torahtom

Well-known member
Joined
Jun 24, 2007
Location
Elizabeth, CO
TDI
1996 Passat Sedan, 250K
Thanks Todd. Do you think the wire connector looks bad? The metal frayed section was about 1/4 inch without insulation.
So the control module box should still be good? I thought it might have as circuit board in it that might have got toasted. I replaced it 6 years ago when I could still get the part after the original one melted in the same place where the hot wire connects to it.

Do you know what the red hot wire circuit connects to? It should be something in that circuit.

What ever it was, blew the 109 main power relay and the glow plug light, odometer, and other instrument lights did not work.
 
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ToddA1

Top Post Dawg
Joined
Aug 3, 2011
Location
NJ 08002
TDI
'96 B4V, '97 B4 (sold), '97 Jetta (scrapped)
Well, I can see green corrosion in it, so unless you plan on taking it apart and cleaning it, just get another ring terminal and splice some wire in. You’ll probably want to cut back the insulation from where that terminal was connected to, to be sure you’re splicing into good wire.

I prefer to splice stuff like that with non insulated crimp terminals, then cover with adhesive lined shrink tube. You can pull the insulation off insulated terminals if needed.

Without looking at a diagram or a car, I can’t tell you where that wire starts. Start chasing it…

-Todd
 

torahtom

Well-known member
Joined
Jun 24, 2007
Location
Elizabeth, CO
TDI
1996 Passat Sedan, 250K
I cut back the wire already and put a new connector on it. Did not need to splice any wire as I only took off about 1/4 inch of wire. It goes into the a wiring harness that is all taped up along the firewall.
 
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