98 12v owners, please look here

[myusername]

I'm asking for a quick favor for someone who owns a 98 12v.

If possible, can you take a look at your engine wiring harness and tell me what plug comes out of the wire loom with the fuel heater plug? It looks like tan/orange stripe and black/blue stripe wires.

I bought a harness and this plug is cut off, I'm thinking it's the coolant temp sensor but not 100% positive.

Also, if you own a 98 12v 5 speed truck, is there only one plug that goes to the transmission?

Thanks in advance!

 

[jedeka]

my 96 coolant temp sensor is a one-wire connector. The wire color is purple with yellow tracer.

 

[95cummins5.9]

If only 2wd the only plug on the transmission is for reverse lights.

 

[myusername]

The harness I got is from a 2wd, so that makes sense. The 95 this drivetrain was robbed from had a 1 wire coolant sensor also. I could be wrong, but I believe they did something different for the 98 12v's and moved the coolant sensor more towards the center of the head right behind the p pump. The part number is different also, and it looks like a 2 wire sensor

 

[Ram12vcummins]

The pictures are off a 97 with nv4500 an I crawled under my 98 with a nv4500 and it appear the same just the heater wires are routed differently. I used the 97 because it sitting on garage floor an easy to take pics.



It appears it's a yellow stripe black wire and red wire with black stripe feeding it. Then you can see how it feeds the two parts. Personally I would remove the heater and put a block off plate in to Avoid issues.


Front electrical plug up by shift tower and only other plug is vacuum one I believe

The last pic was off my 98

Hope this helps

 

[Ram12vcummins]

There's a short stub connector with tan/orange and black/blue coming from harness an connecting to go behind fuel filter mount on my 98. I can't feel right in there but the only port under there I believe is coolant as its tucked up an goes into the head so I, guessing that what your looking for.

 

[myusername]

Awesome. Thank you for taking the time to get those, much appreciated. I won't be using the fuel heater, just trying to figure out what the other wires went to. If it's all tucked up in there, that's probably why they just cut it off

 

[myusername]

After looking at rock autos catalog, it appears a 98 12v vin code D uses the same sensor for coolant and intake air temp? Does that sound right?

 

[stubz616]

On my friends 98 12 valve the coolant temp sensor is forward of the fuel filter housing tucked up under the head and there is a jumper harness that goes from the sensor out to the main harness that is about 8-10" long.


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[GAmes]

I no longer have a '98 engine, but when I did the temp sensor was at the rear of the head and was the same size and same location as the '97 head. The '98 sensor itself had two wires, so I had to use the '97 sensor. No one has mentioned the water temp sensor that is installed under the intake plenum on CA EGR equipped engines. I have never seen one, but they are talked about in the FSM.