Electric fan relay/temp sensor/temp gauge?????

Finishing up my electric fan relay conversion. New problem. I have the relay wire and temp gauge wire to temp sensor. If both are connected to sensor. I can turn the fan on with key off, by a switch. But it won't shut off. I unplugged the relay wire from sensor and fan shuts on and off with key off... any ideas why I can't run both? I followed the schematic as shown.

 

I believe the sending unit needs to be the kind the grounds itself to engine block to turn on fan one you have is alway sending to gauge

 

The fan sending unit is just a switch, turns on and off at specific temperatures. Your gauge needs a thermistor type sensor that varies resistance with temperature.

 

I realized that. I'm looking into aftermarket Stat housings that are tapped for sensors

 

Or you can just put a tee for the gauge sensor in the top radiator hose. Separating the relay from the gauge should take care of your problem.

 

A tee?? and yes I said once I took the rely wire off, it worked fine

 

get the thermostat housing with the tapped hole and install tour fan switch in it, using a tee could be an air trap

 

Air trap? This is how I did mine and it works fine. Earlier I said about putting it in the top radiator hose, I meant to say top heater hose.

 

I was picturing a tee on intake for some reason I see now what you did, however I dont see how that would give an accurate temp reading

 

The water comes from the same place as where the sensor is normally placed, the front of the intake manifold, and the coolant is constantly circulating through the heater. When I added EFI I put the sensor for that in the usual location and moved my gauge sensor to the upper heater hose. The coolant temperature as measured by the EFI display and the gauge are within a few degrees of each other.

 

You are on the right path. Get the aftermarket stat housing with the sensor provision as modmav suggests. That is what I have and it will fix your problem. It also allows you to exchange temperature sensors to control your electric fan operation.

I also have the optional cooling fan overide switch mounted under my dash.

 

I ended up ordering this to give it a try. Should solve my problem from what I read and heard online.

 

I looked online for a few hours. Only 90degree one I found with tapped for sensor was the mr.gasket chrome one. Alot of bad reviews on chrome chipping and surface not being flush

 

Why 90 degree? Our vehicles didn't come with that design of housing. I use the one on the Auto Zone site. Link following.

http://www.autozone.com/cooling-hea...r-works-water-outlet/141903_0_0?checkfit=true