My '88 doesn't cool well at low speed. I found the aux fan isn't coming on and part of that is because the motor is bad. There's also a problem with the wiring, but I know how to fix that. My question is whether I'll have better results replacing the aux fan motor with SNG Barratt's drop-in replacement for about a hundred dollars, or if I'm better off going with a whole aftermarket fan assembly.

Thermostats are new. Radiator recently rebuilt. Rebuilt water pump, all new hoses, new engine driven fan and fan clutch. It still gets hot at anything over about 65 F.

 

How hot is 'hot"?

Inability to hold temp at anything over (mild) 65ºF ambient conditions suggests, to me, that there's more going on than just an inoperative aux fan.

Anyhow, are you contemplating replacing both original fans (elec and mechanical) with aftermarket? Or an aftermarket replacement for just the existing aux elec fan?

The former has many fans (excuse the pun ). Not sure about the later.

I still run the original set-up

Cheers
DD

 

The mechanical fan is new and seems to be working as designed. I'm looking for a repair or replacement for just the aux.

To give you some numbers, I just ran it to the post office and back, then opened the bonnet and shot some temperatures with my IR gun while the engine idled. Temp gauge was at the top of the N. I got low 200s on the hot side of each thermostat housing and 165-169 on the cool side. Ambient is about 52 F. Thermostats are new and supposed to be the right ones but I didn't test them before I put them in. Last time I drove it back from Fallon (70 miles), the needle put quite a bit of space between itself and the top of the N. In town made it worse than highway speed. Ambient was about 65 at the time. I didn't get the IR gun on it that time.

 

Mine did that, due to the wrong Thermostats, they didn't fully open and close the bypass pipe. thx to Doug and Grant for posting the correct ones. ill try and see if I can find the correct ones they recommend its been a few years. Im sure one of them will chime in. Also im a "fan" of aftermarket AUX fans

 

By all means get the aux fan operational again, on GP. But I'm sure something else is afoot here.

On last assembly are you sure you got all the air out of the system? If not, bleed it again.

If no joy, remove thermostats for testing...and to make sure they are the correct length

Cheers
DD

 

Any idea what the stock aux fan flows?

 

Very little. Far better to replace with a modern SPAL. Cheap aftermarket fans are a waste of effort, sad to say.

 

Pardon my ignorance, but how would I know if I got all the air out?

I found this site with a link to one on Amazon: https://foreverjaguar.com/f/axe-your-aux-fan-for-this
Any thoughts? It's only about 50 USD more than the stock replacement.

 

Any SPAL will do the job that fits, just buy the highest amperage one they offer!

 

Truth be told, you never really know. It's not like you can see inside the system. It's one of those 'level of confidence' things.

Naturally you bleed until you have a steady, solid liquid stream coming from the bleeder. But, IME, sometimes a second go-round reveals that there was still air in the system.

Cheers
DD

 

I've read through that website and found it to be helpful on several topics. I copied his approach on the aftermarket aux fan and purchased this one off of ebay: https://www.ebay.com/itm/124149553704
Quite a good price for a Spal 10' fan.

 

Ordered. In a week and a half I get to see about putting it in. My employers have conspired to make me work 19 days in a row, so progress is a little slower than I'd like. Now I get to see about fabbing up a substitute for the missing front air dam, right after I change the oil and re-bleed the cooling system.