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overheating question (radiator and fan)


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While driving the other day the temp gauge on my '86 brat started heading towards the red. Pulled over immediately of course, let her cool a little and check the radiator...prett much empty (as was the coolant reservoir that had been added previously).

 

Got her home and spent some time examining her to the best of my beginners knowledge. What I thought is the radiator fan does not come on at all....and there is some evidence of leakage at the top drivers side edge of the radiator, although when I put some new coolant mixture in and let her run I didn't see anything leaking.

 

My understanding of cooling systems is still limited, but is it possible that the fan not functioning could have caused the radiator to have too much pressure and crack?

 

My test light shows no power to the fan. The fuse seems fine (it's the one under the dash yeah? Or is there a different one I'm missing?). My trusty little 'how to keep your Subaru alive book says there are a number of other things to test, but I haven't had the chance yet.

 

 

Thanks all for your input! I really appreciate your helpful kindness :)

 

P.s also wondering where to source a good radiator and fan if ends up that they need replacing.

Edited by belacane
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 hi,

 the first thing to check is the connection to the fan temp switch on the radiator, pass side down low , below the battery , has a single yellow wire to it.   the switch  ( when it is on )makes the ground for the fan .   with the " Ignition On " if you jumper the yellow wire to ground , the fan should run ,  if it does , then the connection to the switch , or the switch , is bad.   if the fan does not run with that test, you need to disconnect the fan and jumper  the fan wires to a 12v,  and ground , to test if it is good or not.   my 84 wagon used to have corrosion trouble with the yellow switch wire making connection, maybe cause of the battery right above or whatever.

 

 

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Ok I figured it out....and what I thought was the a/c fan ran when I jumped the ground, but now I'm confused as to which fan is which....in the picture below, which one is the radiator fan and which is the a/c fan? The fan on the right in the picture is the one with no power to it according to the test light. The fan on the left in the picture works fine and also came on when I jump grounded the fan switch as well as when the car is idling at operating temp

 

I got her during winter last year, and moved from a cold climate to a hot one before she ever got to experience any hot weather, and I'm wondering if the fan on the right in the picture (the one with no power showing to it) has never been operable since I've had her, and I'm just experiencing the overheating for the first time (and cracked the rad) because of the hot weather here...hmmm.

 

IMAG0795_zps6a556b24.jpg

 

UPDATE : found a big leak in the radiator, dripping water all over the ground while I was letting her idle for the second time today...ok, I guess that's the problem :)

Edited by belacane
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Hi,

 Ok ,glad you got that figured and found the leak.   the pass side fan is the main fan,  the thin driver side one is the a/c fan although you can wire them to run anytime. 

  If your radiator is in good condition it will cool the motor with just the main fan,   a/c not on,   if you plan to run the a/c you should get the aux fan working.  also there are single row and dual row radiators,  obveously the dual is more efficient but a single is adequite in most areas if it's in good clean condition inside and the  fans working.

 get it cleaned and the leak fixed and you should be good to go,,, check the thermostat also they get prone to stick when old.    there has been some discussion on factory or aftermarket thermostats, personally i feel more confident with factory on this part, but thats my opinion,  they do have a bigger opening and are built more sturdy than aftermarket ones.

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I don't have links to any of the sites, but I've bought a few radiators from on-line stores.

All EA81 radiators selling now are dual core and come with the cooling coils for the auto trans. One size fits all.

Last one I bought was around $130.00 to my door.

 

Be sure to swap the short grounding wire over to the new radiator. It's located right on top of the radiator near the left mount bolt in your pic.

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I don't have links to any of the sites, but I've bought a few radiators from on-line stores.

All EA81 radiators selling now are dual core and come with the cooling coils for the auto trans. One size fits all.

Last one I bought was around $130.00 to my door.

 

Be sure to swap the short grounding wire over to the new radiator. It's located right on top of the radiator near the left mount bolt in your pic.

 

There wasn't a hole to swap it into on the new rad. I'm going to have to drill one.

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There wasn't a hole to swap it into on the new rad. I'm going to have to drill one.

Ground wire doesn't need to be in a specific spot, it just needs to be there. You can use one of the fan mount bolts and run a longer wire to reach the body.
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  • 2 months later...

Ok I am new on this forum and a shade tree mech..  The 86 brat I am working on, I traced the fan motor that is on the DRIVERS side. This motor is not associated with the AC. The wiring on this motor has led me to a relay located on the passengers side fire wall and this relay is also connects to a temperature probe next to the top radiator hose.  I am however having trouble finding the cooling fan switch. Any help would be greatly appreciated. 

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