The coolant temp gauge recently started acting increasingly erratic, and then seems to have quit altogether. I assume that the sender went bad, so I have purchased another, and a thermostat (both Cummins) that I will pick up Monday, and flush then install. My diagrams show the sender being in the rearmost driver side port of the cylinder head, but on my truck there is a plug there. There are 2 wires that disappear behind the fuel filter, is this it? If so I'll have to remove the fuel filter housing, at which point I might as well do the filter again, and a few lines. My truck is a 98 12 valve, every diagram I've been able to find shows the sender in the rear corner. Any thoughts?

 

Mine is about middle of the head, by the gov housing on the pump. Its a pain to to get at. Can't even really see it. I pulled the wires out of the connector for the temp sensor when I yanked the head.

 

Ugh. I'll take pics as I go so this question is put to bed, hopefully. Wish me luck, or patience.

 

First picture shows where it's supposed to be. Second shows the 2 wires that disappear behind the fuel filter. Third shows what looks to be a sender, I held the camera down low to get that picture. I searched and can't find a sender forward of this in the head, so I'll assume this is it. Can anyone verify the colors in the wire harness that go to the sender?

 

sorry guy i went looking for mine and found same frigin plug, i gave up but would like to know if you find it.

 

Thanks csa, I'm waiting to hear back from the dealer and cummins. I'll post back the results. The sender has a 2 wire harness and plug on it. It's the only sender that side of the head. The dealer is stumped, cummins guy was up to the challenge though.

 

My 97 did this same thing. The sensor was on top at the firewall. Had one wire plug going to it. I took the plug off, pulled the wire out of the plug, adjusted it where it would fit tighter then reinstalled the plug. Since then I haven't had issues. Sensors like that one don't generally just go bad.

 

This might help. But I don't see any of those positions in your photos..