'94 Rodeo overheating issues

1st time poster here - thanks!

My daughter's '94 Isuzu Rodeo is having overheating issues. Not that the gauge is hitting red, but it is getting HOT! I live in Reno and summer temps have been 90-100. The system is recently flushed, thermostat removed, and 50/50 coolant. On the freeway - no problem. Around town the temperature gauge gets to the 3/4 mark. If I turn on the heater (flow bar) = better, if I use the heater fan then I am back to around the 1/2 mark on the gauge. The one thing I have noticed is; I can't get the outer electric fan to kick on (the one outside the A/C cooling core). Is there a fuse associated with that fan, does it work with the engine temp or just the A/C? - I can't find that information (or a fuse). Also, as a side note, when snooping around with the electrical connections to this fan I noticed a corroded out electical connector. The two wires are black with and orange stripe and green with an orange stripe. These wires come out of the same wire grouping as this electric fan harness, but head AWAY from the fan not to it. Sorry for the lengthy post, but I wanted to get all the info out there. Thanks & HELP!

I do really want to know about a fuse associated with the electric radiator fan, and when it turns on.

how many miles?

many folks with your issue, typically flush the rad, then change the thermostat, and maybe even switch out the clutch rad fan and still have problems. Then the come here looking for help. The next thing we recommend you to replace is the radiator. If it has 150k or more it is time.

So I would look into replacing the rad.

As the small electric fan infront of the ac radiator, that should come one when you turn on the AC (or when the compressor cycles).

Thanks Ryan!

Is the radiator install very difficult? Yes, I am very mechanically inclined. One of my hobbies is classic cars. I have a '55 and '56 chevy. I just hate working on any vehicle beyond the 70's.

I have never done it on a rodeo but have done it one a S10 and a prelude and never had any issues getting them in and out.

I've done it on my '97 Rodeo with the 3.2L and it's very easy. Easier than doing it in my Jeep even. Remove the upper fan shroud (couple of bolts and two clips) and the hoses, and there are two nuts on brackets on top of the rad. It's out. If you have an auto, you have to pay attention to the ATF cooler lines at the bottom. It's probably good to top up the ATF afterward.

My VW Jetta was a bear, on the other hand. I had to remove the front bumper cover, wheel well liners, get in behind the A/C condenser, yadda, yadda, yadda. No fun. All 3 vehicles should be good with the rads for another 150K.

Surferfletch - did you have to remove any of the driving belts or fan clutch? Is it possible to clip off the transmission cooler lines fast enough?

Again, this was on my '97...

Cooler lines come off quickly with the factory spring clamps and you lose little fluid. You know how to top it up anyway! I replaced those clamps with screw type clamps.

And you don't need to touch the belts or fan.

This was easily the simplest job I've done on either my Jeep or Rodeo. It took me much longer to put a cargo rack on my Jeep yesterday.

You know how to top it up anyway! I replaced those clamps with screw type clamps.


Yes, but I'm tired of dealing with the transmission, finally got all of it's leaks stopped. I know the clamps on those lines are the screw type, installed those when I bought it - learned that mistake from my 1st Rodeo.

Thanks.

You said you removed the thermostat? So it doesn't have one now? That could be your problem. The lack of a thermostat can cause overheating since it acts as a slight restriction to coolant flow. If the coolant flows too fast, you either don't pick up the heat from the engine or it can't get cooled off in the radiator. There's no reason to remove the thermostat, no matter what the climate. Put a new one back in.