Temp Sensor With Cluster Swap

[Kona]

So replaced the cluster with a 90 xj, changed the temp sensor and oil sensor, well now I broke down from overheating because the electric fan won't kick on, the fan works but I was reading that the temp sensor may be at fault, anyone experience this issue? It was fine prior to sensor upgrade

[cruiser54]

Temp SENSOR for the fan is in the radiator on the driver's side. The temp SENDER for the gauge is located on the head, rear, driver's side. Two different animals and unrelated.

[Kona]

Well, I took out the temp sensor that I bought and put the factory back in and the gauge works fine an the fan now works and comes

On right at 190•, without loosing all my coolant, so I guess they might be related somehow !? It's working perfect now

[Eagle]

Your post says you have a '90 MJ. The photo shows that you have swapped in a late-model front clip. Did you by any chance change to a newer wiring harness? Where is the temp sender you changed located?

[Kona]

Mine is a 88 w/99 clip, all original harness, the cluster is from a 90xj , but like I said its working fine

Now that I placed the original sensor back ,

Sensor is back / driver side of block by the valve cover on top.

[Eagle]

That sensor has nothing to do with the aux. fan -- it only controls the gauge. The sensor for the aux fan is the large(ish) plug halfway up the driver's side radiator tank, with two moderately heavy-gauge wires coming off it.

[cruiser54]

That sensor has nothing to do with the aux. fan -- it only controls the gauge. The sensor for the aux fan is the large(ish) plug halfway up the driver's side radiator tank, with two moderately heavy-gauge wires coming off it.

 

Correct. Must be a coincidence.

[MJCARENA]

Did it really overheat or did just the gauge indicate hot? I also thought that the fan turns on around 230 degrees.

 

[Kona]

The gauge went up to normal 210 running temp, the fan comes on at 210(sorry), so it didn't and blew the cap from the reservoir and leaked everywhere, guess it was a coincidence , but it works now so I'll just leave it alone, looks like Kona is very temperamental !

[Eagle]

The aux fan does not come on at 210 degrees. 210 is the normal operating temperature. The aux fan doesn't kick on until something like 230 or 240 degrees (or the dash gauge).

[Kona]

Well mine kicks in at 210

[Exgrayxj]

Mine, with a temp guage in the tank comes on at 210, and coincides with the guage.

 

There is a Napa cap, made for a Volvo, #703-1396, that will not blow off.

I can't take credit for finding this, but mine is now holding pressure, to the point I found I also had a seam leak on my chinee made tank.

So I went to the jy and got an old original that works fine...

 

A wise old codger on here told me about the cap when I had the same problem. Can't remember who tho.

 

Also, I put one of those coolant flush things (to hook a hose on) on the highest point of my heater hose, filled things up with the cap off until I got only coolant, and have had no problems since. Been a couple months (I think)

That sound you hear is me knocking on wood.

[cruiser54]

You caling me a codger? LOL.

 

218 is the temp that the fan is supposed to turn on.

 

Excellent way to fill a closed system BTW. This old codger uses the same method.

[Exgrayxj]

AHA!

I thought someone would take the bait!

 

Thanks for the tip, btw.

 

Knock on wood, things are working correctly now, with a new fan clutch,shroud, tstat, tank, AND A VOLVO CAP, it has made me a happy camper!

 

Now on to the rear axle...

[cruiser54]

This old codger loves happy endings. On to the next problem............