Coolant ports

[XLTbeater]

I am looking for extra or empty coolant ports on my '91 4.0L. Going to attempt an electric fan install (16" Flex-a-Lite) with a T-stat control. Had this installed on my Malibu a while back, but the sbc had a couple plugged ports to choose from. How did you guys plumb in the T-stat; for those that had them?


XLTbeater

 

[RonD]

Good place is the upper rad hose since it is the IN hose for the rad, so it's temp would dictate when/if fan should be used.

Look at the pictures at the bottom of this article: http://www.therangerstation.com/tech_library/volvo_electric_fan.shtml

You can make one or get one from a wrecker.

I like the lower rad hose since it has rad cooled coolant going back into the engine, if you are driving 60MPH you don't need the electric fan on, in most cases, lol.
Only when driving slowly or stopped do you need the extra air flow thru the rad, and you can set temp sensor for that temp increase.

You could add a temp sensor to the Temp SENDER wire, using diode to keep gauge accurate.
But the sender is on the engine side of the thermostat, so fan may be on more than needed, but not a big deal.

On the '91 4.0l there are two temp units on lower intake near t-stat housing
The 2 wire ECT SENSOR, only used by the computer, don't mess with that one
And the 1 wire SENDER, it is a variable Ground for the Dash board temp gauge, and can be used as such for your electric fan trigger sensor

 

[XLTbeater]

Thanks RonD!

I am reading that thread. I might be able to do something before the weekend. I have a bad water pump that I am going to replace. Figured since the fan looked pretty bad last time I removed it; I would replace it with my e-fan. I'll see if I can make this happen.