inhibit switch bad

[mhagie]

I have now tried 2 new glow plug inhibit switches from O'Reilly Auto Parts and neither are any good.
I can suspend switch in a pan of water on stove connect ohmeter to leads and turn on heat, they will go clear to boil with out breaking contact they are suposed to break at 125* but neither does.
Now the question is where can I find one that will work???
I know that I can jumper leads together and get by but I like the idea that glow plugs are not needed at normal operating temp.
Any ideas?..........Merle

[diesel65]

I don't think you will find one that opens because GM had a service bulletin for the 6.2 for hard starting with warm engine.
GM found that even though the engine was warm it still needed a glow cycle to make easy starting on older engines.
The bulletin said to replace the thermal switch with new part #, I happened to break one and found that it only has a shorting bar.

[mhagie]

That explains it as to why mine don't operate, during the search to find switch I found that Auto Zone could match up oem part number but it cost double the O'Reilly switch now I know why.
Thanks........Merle

[mhagie]

Well not being satisfied with a inhibit switch that don't inhibit I came up with a plan,we'll see how it works.
I have a 84 controller left over from my gas to diesel conversion, I went with the 85, style so I connected one side of the inhibit connector to the blue wire #3, the other to the black wire #6 using the diagram from the troubleshooting guide I reason that continuity will break at 160*.
Not as good as the original inhibit switch at 125* but acceptable,I just don't buy this crap of cycling glow plugs at normal operating temp.
Still wish I could find a real inhibit switch that actually switches...........Merle

[RaptorMan555]

Found my inhibit switch thru local Chevy dealer for my 82 6.2 w/Banks and 80 GMC w/ 6.2 conversion w/ Banks.