Radiator fan not working, help please

lalojamesliz1

New member
Hey guys, a few years ago I cracked ringland #3 and I was in the middle of buying my house and because I had nowhere to work on my engine and I needed the cash for my house down payment I had to sell my all-trac. The guy that bought it had a gen3 engine and trans installed but it's running gen2 electronics.
I've got everything going good again but the fan for the radiator won't come on and it'll overheat if I just let it sit and idle.
I replaced the fan no.1 relay with a new one, I applied power to the fan by unplugging it and running battery power straight to it and it does work, I unplugged the radiator temp sensor and jumped the connections on the plug and I hear the fan relay and the a.c. fan relay both click but the fan just doesn't come on.
Any ideas?
It's a 91 all-trac
 

underscore

Well-known member
Did you check the fuse? If the fuse is good make sure the relay has power coming in from the fuse with the ignition on. If that's good start checking individual sections of wiring with a multimeter. Btw you can just unplug the temp switch on the bottom of the rad to force the fan on when the key is on, you don't need to jumper it.
 

lalojamesliz1

New member
Thanks for replying,

I checked the wiring and plugs and they have voltage but just not the amperage needed to run the fan. I tried to see if I can use the plug from the harness to trigger my own relay I wanted to add but it didn't put out enough power for that either.
I continue what else I could do so i have up. I spent a lot of time yesterday and today trying to figure this out.

I have a ron francis ar88 adjustable temp fan relay kit coming tomorrow that's for the mustang I'm building but I'll just use it on my all-trac for now since my mustang is far from using it right now.
https://www.ronfrancis.com/prodinfo.asp?number=AR%2D88

I just don t understand, I replaced the relay, I checked the wiring and plugs, it has voltage but I just don't know what's left :shoots:
 

lalojamesliz1

New member
Do all gen5 celicas have the same fans or all-trac specific? I need to go to a junk yard for some parts and maybe i could get anotger fan if it coul just be the issue.
 

FC Zach

Active member
lalojamesliz1":20issnp6 said:
I need to go to a junk yard for some parts and maybe i could get anotger fan if it coul just be the issue.

Have you tested and checked the fan off as a possibility? Seeing that you have bypassed the relay, the fan or faulty wiring is my guess.
 

lalojamesliz1

New member
FC Zach":4qbd4re3 said:
lalojamesliz1":4qbd4re3 said:
I need to go to a junk yard for some parts and maybe i could get anotger fan if it coul just be the issue.

Have you tested and checked the fan off as a possibility? Seeing that you have bypassed the relay, the fan or faulty wiring is my guess.

I'm guessing the fan or wiring also. I did check the fan out by cutting off the plug and directly connecting it to a small sealed battery so I'd like to think it's fine. I'd like to figure this out but for now I need to get the fan working so I can drive my all-trac and get it smogged.
 

FC Zach

Active member
Any reason for
lalojamesliz1":2ibadi1o said:
cutting off the plug and directly connecting it to a small sealed battery. . .

as opposed to unplugging connection and using test leads or removing terminals from connector?

And I'm assuming the fan worked? If so, is there any corrosion in the connector?
 

underscore

Well-known member
Have you checked the continuity of the ground wire of the plug for the fan? You can have a 12V supply with all the current in the world available, but if there's no ground connection it's not good for anything.
 

lalojamesliz1

New member
FC Zach":1tmu533v said:
Any reason for
lalojamesliz1":1tmu533v said:
cutting off the plug and directly connecting it to a small sealed battery. . .

as opposed to unplugging connection and using test leads or removing terminals from connector?

And I'm assuming the fan worked? If so, is there any corrosion in the connector?

Honestly, it was already cut for some reason. So I just took off the tape pulled it apart and soldered it back together after I tested the fan. Yes it worked and no corrosion. This car has hardly any rust. Only rust I've seen is a couple quarter sized spots on the rear quarter panel edge by the wheel
 

lalojamesliz1

New member
underscore":s5tf1t77 said:
Have you checked the continuity of the ground wire of the plug for the fan? You can have a 12V supply with all the current in the world available, but if there's no ground connection it's not good for anything.

I have not....... sigh
I'll check and post the results
 

lalojamesliz1

New member
I thought I updated this earlier..... perfect continuity on the ground side.
I received my fan controller and it would have been PITA to install it because the controller has to be in the cabin so I just ran a relay with a toggle switch for the fan to come on. I'll just keep a eye on it.
The only thing I have left so I feel it's reliable is to add a coolant overflow bottle. It has a nice mishimoto radiator but it had a bolt in the hole for the overflow nipple/tube. The threads were messed up with that bolt because of the coarse threads on it . Its a small mess but I managed to install a nipple-tube for the hose that leads to the overflow bottle and I ordered the bottle off Amazon.
 

lalojamesliz1

New member
FC Zach":26cuos21 said:
lalojamesliz1":26cuos21 said:
It has a nice mishimoto radiator but it had a bolt in the hole for the overflow nipple/tube.

WTF?! Why?

That is exactly what I said to myself when I saw that :nono:
The filler neck isn't very thick and the threads it had are gone. The only available nipple tube for me is the one from the heat exchanger for my intercooler so I switched them since I had the heat exchanger nipple plugged with a hose with a bolt on the end.

Luckily the nipple I took off is like a wedge bolt to were it gets thicker the more it goes in. I don't like it 100% but when i find a reputable shop with a tig welder I'll ask them to seal that nipple I put on permanently
 

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