So i got motor in and all. it starts, runs beautifully, and all gears work and 4x4. only thing now is it doesnt seem to cool down, iv let it warm up a few times but temp keeps going up. I have not let it get into the red cuz i dont want to blow it up obv.

I never installed the fan back on the truck, i was going to wire some electric ones after i got it running but at 12 degrees outside should it be having problems with heating?

 

ya you need the fan to pull air through the radiator. when your not moving you have no air flow and no cooling .do you have a thermostat installed .

 

Did you install a thermostat when you swapped motors? If not, do you know which brand/temp rating came in it? I would fair to say the thermostat that is in there is stuck closed. I would just run down to Advance, and pick yourself up a new Stant Super Stat, they will last forever.

 

the stats are pretty easy to replaceon tese trucks. just remove the alternator move the ac lines and bracket and upper radiator hose. then reinstall in reverse. ive had to get at mine a couple of times and now can do it in my sleep.

 

it wont over heat w/o a t-stat, itll just run in open loop.

it does need a fully functioning t-stat, however, your problem 100% is that you have a radiator that is not able to transfer heat because there is no air flow- so definitely put the fan on man, no worries tho

if you really wanna test the theory run it down the road at 55 and see how it does

 

ya its a brand new Tstat but i did forget to test it. the last one i installed when i put the airgap on work nicely so i just didnt test the new one, bad idea i guess.


But ya a fan will be on this weekend, i was just hoping to have it work without a fan until i got an electric fan installed.