1990 radiator and cooling system upgrades

i recently bought a 90 jeep renix with 4.o liter and guy ghetto rigged a lift kit on it and had burried in mud to where its hard to really see anything in engine bay, i can see he has some ghetto squeeze clamp with a wire going to fan so im assuming thats only way the fan works. radiator has a pin hole leak, i plan on making it weekend wheeler/crawler at some point-never street legal. i am wondering what you guys recommend? do i ditch factory electric fan and go with a complete kit or what?

Get a radiator with a cap on it that also has the temp switch threaded hole. Convert it to an open system that way. You'll need a recovery bottle.

I upgraded to a two-core Champion aluminum radiator after my second OEM style plastic-tanked unit failed. So far so good as I'm thinking I should have started with the aluminum unit. Do a google search. 2-core, tig-welded aluminum tanks, and a CNC machined filler neck!

The original closed system is fine. The only problems generally are leaking caps, and overflow bottles. I converted my 90 to open a long time ago since it needed a new radiator anyway. The 3-row copper GDI radiator did not work any better than the original factory two row when it was newer. I've been using a two row aluminum/plastic for the last 5 years and it's worked fine.

I'd wash the mud out of the engine compartment. The electric fan should come on when air conditioning is turned on, or the temp goes over 210 in theory. The temp sensor is a switch in the lower left hand side of the radiator. Don't spray water on the throttle body/TPS.

what if my a/c is not working? mainly a trail rig not really worried about a/c?

Selecting A/C on the dash control should cause the aux fan to come on. Whether the A/C system is charged or not shouldn't matter.

Some of us routinely unplug the compressor clutch electrical connector when we're running hot so we can use the AC switch as an aux. fan override without the extra engine load from actually running the compressor.