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Electric in line thermostat

N

Nwcharger

NAXJA Forum User
Location
Eatonville
Has anyone used one of these? I have a stock 87 Cherokee with the closed system. I plan on lifting it, tires, etc. I replaced the stock system with a three row, all aluminum radiator with 2 10" electric fans. I have the first fan wired to the ignition so it comes on/off with the key, and the second to a switch in the cab. I also replaced the thermostat. The jeep does not get above 150 degrees now. If I unplug the fan from the ignition it will get up to 210 no problem. I talked to a buddy and he was telling me about these electric thermostats you can throw in the radiator line and it will kick the fan on at a certain temperature instead of running it continuously. Anyone have any experience with these?
 
Sure, tee for two at the thermostat housing. One goes to your O.E. CTS

and two to a RBM speed control with adj. dash pot i.e. VSC. The O.E. will

turn on est. 212*f and a aftermarker at your desired temperature setting.

No CYBERBULLYING here. HAGO.
 
Nwcharger said:
I have the first fan wired to the ignition so it comes on/off with the key, and the second to a switch in the cab
Click to expand...
are we sure the thermostat is installed correctly and working properly?

Talyn said:
Why not just find the reason the electric fan is coming on early? Temp senders? Maybe the gauge is wrong?
Click to expand...

it's installed that way, but I don't think there's any good reason for it to be that way.... if it runs cool all the time, the fan should have a controller to turn it on after things reach operating temps.
 
Shorty said:
it's installed that way, but I don't think there's any good reason for it to be that way.... if it runs cool all the time, the fan should have a controller to turn it on after things reach operating temps.
Click to expand...
You know, I completely over looked this part:
I replaced the stock system with a three row, all aluminum radiator with 2 10" electric fans. I have the first fan wired to the ignition so it comes on/off with the key, and the second to a switch in the cab.
Click to expand...
For some reason I thought that it was the stock e-fan that was acting up.

But, yes he need some sort of thermostatic control for the fans.
 
The thermostat is supposed to keep the engine at a minimum temperature. A fan running all the time should not affect the thermostat operation. Once the engine hits operating temp the thermostat should open and allow coolant to flow through the radiator. Even if there is ice cold water coming in from the radiator the thermostat should allow the engine coolant to recirculate within the engine block and heater core until the coolant hits operating temperature.

I would take a look at your thermostat and maybe just put another new one in.

EDIT: What temp thermostat do you have in it? 180* minimum if you want the engine to operate in closed loop.
 
Last edited:
The jeep did not have a OEM electric fan when I got it. Im not sure if it didn't come with one or someone took it out. I removed the mechanical fan and am just running the two electrical fans that came with the radiator. The thermostat that was in the jeep and the new one I just replaced yesterday were both reading the same temp. About 150. Im almost wondering if the temp sensor is bad? It is a 195 thermostat. But if the temp sensor is bad why would my jeep get up to 210 when I unplug the fan running to the ignition?
 
I'm wondering what became of your O.E. wires from the fused relay in PDC. A green or light blue 12 gauge wire would have supplied power to your elec. fan RBM. You would have had elec. fan use at 212*f, or once your HVAC defroster was switched on. You could power a second fan from another source and set an on temp. as suited to your engine use. Why your temperature read rises once you unplug a elec. fan from your ignition source sound like a fault with a CTS.

Luck.... best of.
 
Bryan C. said:
The thermostat is supposed to keep the engine at a minimum temperature. A fan running all the time should not affect the thermostat operation.
Click to expand...
While in theory it should work like that, but it doesn't. I recall several times on down hills under light loads the engine started to drop below operating temp.
 
Nwcharger said:
Im almost wondering if the temp sensor is bad? It is a 195 thermostat. But if the temp sensor is bad why would my jeep get up to 210 when I unplug the fan running to the ignition?
Click to expand...

Perhaps it is reading low. Perhaps when it says 150* its actually around 200*. and when reading 210* its close to over heating. Do you have an IR temp gun? I would verify the temps compared to the t-stat housing.
 
Talyn said:
While in theory it should work like that, but it doesn't. I recall several times on down hills under light loads the engine started to drop below operating temp.
Click to expand...

That doesn't sound out of the realm of possibility. Dropping below for a short time isn't what I consider a problem.


I think the OP is right to check the temp guage. I know on my rig the temp guage reads slightly higher than the actual temp as read by the pcm. The sender for the guage is cheap enough that it might be worth a try to replace it and see what happens.
 
Bryan C. said:
Dropping below for a short time isn't what I consider a problem.
Click to expand...
I don't consider it a problem either. You should have seen the gauge drop in the dead of winter.
The sender for the guage is cheap enough that it might be worth a try to replace it and see what happens.
Click to expand...
That would be a good option.
 
Also, using a IR temp gun to CONFIRM the temp.
My temp sensor works, but gauge is over about 8-10 degrees as to what the actual coolant temp is.
 
So here is an update. I just changed out the coolant temp sensor and the temperature switch. Now I am getting no reading at the gauge cluster for the temp what so ever. I started the jeep after I installed all of this and let it run for 15 min or so while I was making the kids dinner. I went outside and found the coolant boiling over and the gauge hadn't moved. Im thinking the wire going to the temp switch is bad or a wire going to the temp gauge in the cluster is bad. I am going to tear into it today and see if I can find the issue. Frustrating!
 
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