Have two issues. First is my temp gauge doesnt work. Replaced my temp sensor. No go. Shorted two wires on cts plug together. Didnt move gauge. Swapped gauge cluster, no go. Where does the wiring go?.. I unplugged the sensor and got a code. How does that make sense? I thought the sensor by the tstat only worked the gauge not the pcm? This truck has 2 sensors even though I read 98+ only had one. Is the short somewhere in the dash somewhere before the cluster?

Second is that I have an np242. It was like that when I bought it. I Need to rig up a vac switch to lock/unlock the axle. Would a three way solenoid like this work?http://www.oldairproducts.com/catalog/accessories/25-1020/vacuum-solonoid-p-2924.html I found a few like this but they dont have a discription.

Appreciate the help. Stressing alot over this truck and trying to work out all the issues.

 

99 Should only have one sensor. PCM reads that sensor, sends signal to central timer module, and the CTM tells the cluster what to do with the temp gauge. Do your other gauges work?

If you can, plug in with a scanner, and see what the PCM thinks engine temp is.

Could always get a posi-lok for the front axle.......

 

Im telling ya, I have two. The second is on top of the intake to the front left, right? All other gauges work. Dont have a scanner.

Im confused too. Do 5.9s have only one also?

 

Oops thats the air temp sensor. Dont I feel dumb. Anyway, Ill try to get a scanner to see the temp. Im not throwing any codes so I would guess the pcm is getting a reading.

If the pcm is right, I guess theres something bad between the ctm and the gauge eh?

Posi lock would work but a solenoid seems cheaper and easier. Im on a tight budget. I thought about just keeping it locked but Id like to save what little gas it uses.

 

Most auto parts stores have scanners these days... not all of them will read data though.....

You tried a different cluster? I am not sure what else would cause the issue..... that system is kinda funky.

 

Could it be a bad pcm? Seems doubtful though. I reseated the pcm harnesses, no change. Sensor ohm reading checks out. Trued crossing wires again, no change on the gauge, just made the mil come on so the wiring to the pcm should be good.

About to give up and install a gauge. I got a cheap sunpro gauge but then I realized I cant replace the stock sensor. I dont wanna spend 30 bucks on a hose adapter for the sending unit but I have a feeling Im going to have time figuring this out.