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GP Wire Voltage Range?

D

drag sgt

Active Member
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Location
Oregon, USA
I had a random P0380 pop up a few times near the end of last month; which was strange because it was so warm that I'd think the glow plugs wouldn't even need to come on. I replaced the controller a couple years ago (forget the brand though) so I was going to be a bit upset if that was the problem. I noticed the nut on the constant 12v was loose so I tightened it down and did some testing just to be thorough. All values at the relay tested the same as at the battery (12.5v), but my sample glow plugs on each side tested 11.5v. I assume this is normal due to the large draw to heat the glow plugs but couldn't find anything in the manual indicating what the normal voltage range should be in the GP wiring, so I thought I'd put it out there. I plan on eventually replacing all 8 GPs but know it's quite an adventure to get the two passenger rear so am holding off till I know I have a full weekend free.
 
There is ohm specs for the plugs but don’t use it.
The glow plug can physically wear away from things like contamination that will increase the resistance or advanced timing that will lower the resistance. Yes, both happen and you can have a contaminated half burned up glow plug that tests accurate.

I have found plugs that worked very well and tested bad. My suggestion is buy a new set of AC Delco 60G plugs from an authorized dealer, not Amazon, or any other online place as there are many knock offs. If you want to see pictures of a destroyed piston from a glow plug failing, let me know, that’s why my engine is in 1 million pieces right now.

When you remove the old plugs, if they are not the 60 G, throw them away. If they are, then test them on the bench after inspection. Keep the good ones throw away the bad.
 
As for the wires, you expect a 1 volt drop at the wire to be within normal range when activated? As for the GPs themselves, I have no idea how old they are so I'm just going to replace all of them to be certain and have a record of it. At minimum I may do the easy 6 and save the back 2 on the passenger side for their own weekend.
 
Will L. said:
I have found plugs that worked very well and tested bad. My suggestion is buy a new set of AC Delco 60G plugs from an authorized dealer, not Amazon, or any other online place as there are many knock offs.
Click to expand...

Do Bosch/Beru plugs have a bad reputation for 6.5s? It's what I use in my old TDi and what I see a lot of vendors have.

Local parts stores have the 60G for under $10 so I'm not concerned about cost, just curious.
 
The Bosch has a bad rep for the spade connectors breaking off too easily. just don't get the rapid heats for any brand. they tend to swell and cause you to need a full bottle of aspirin
 
what kinda issues did he have? the 60g's are supposed to be a slow glow that are regulated so they never overheat and swell up. supposedly you can leave them on for hours on end without any ill effects.
 
dbrannon79 said:
what kinda issues did he have? the 60g's are supposed to be a slow glow that are regulated so they never overheat and swell up. supposedly you can leave them on for hours on end without any ill effects.
Click to expand...
But ether can blow the ends off.

I saw it on my sons truck.

He took it in for a starter, they left the brace off, hit it with fluid and ruined his engine
 
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