Relay Confusion

[Bucky92]

I decided to look into my coupes little overheat hiccup he had...tightened the water pump belt..filled up coolant...burped it..got it turned around in the garage...and ran it..first without the cap on ..to watch for coolant flow etc...I saw bubbles ( great not again!!). Well I pressurized the system and ran it ..wouldnt leave LBs side...wanted to catch the over heat before it got out of hand.

 

After 15 minutes of mixed RPMs..the fan never kicked on...and he was hot..not boiling ..but just hot...all hoses were hot ..rad hot etc etc.. So I tested the fan itself..fan is good...that leaves the thermoswitch and/or the relay. I guess it would be best to replace both. Here is my problem..I have been looking in the FSM and...cant figure out which relay is the right one. Sub Fan relay...Sub Fan Control Relay...Pressure switch ( main Fan Control) .

 

I am lost ..help!!!

 

Oh for those who dont know...EA81

Edited December 2, 2008 by Bucky92

[idosubaru]

i don't know crap about your car connie but what i've done in the past is just switch them around if they're the same relays (often times are). often the fan relay may be identical to the a/c relay or something like that, so swap em out. or even just tapping them, they can stick like a starter and some kindly taps might get them working again. of course if they're hard to access none of this helps.

good luck.

[subiemech85]

does your fan switch have one or two wires???

 

if it has one wire, is the radiator grounded, if not, it won't work

if it has two wires, make sure the radiator is grounded

 

one wire system: short wire to ground and fan should turn on

two wire system: connect both terminals and fan should turn on

 

iirc yellow and blue wires

 

all below is just a guess, but a good one:

Pressure switch ( main Fan Control) is for the AC system

Sub Fan Control Relay also with AC

Sub Fan relay is the critter to look at

[Frank B]

Did the bubbles stop after a while?

 

With everything else you replaced on the car, was the radiator one of them? I haven't followed your progress.....

 

Is it the four spade relay like the headlight relays? I think they all are. Anyway, use the Pilot PLRY-1 relay. It's a four spade relay like the stockers, but it's 30 amp, and less than half the price of the "proper" replacement.

http://www.autozone.com/R,2262363/store,2039/initialAction,accessoryProductDetail/shopping/accessoryProductDetail.htm

 

They used to be $3.99 at autozone, but they raised the price????

Do a web search for more info on that relay.

[bratman18]

It's funny I was just outside doing a few things on my brat. I had it running and noticed it was running a little hot, and the fan was not kicking on. I ended up checking the wires and the wire that goes to the little switch that is screwed into the radiator wasn't properly grounded where it should have been. I just tightened up the ground wire where it screwed onto the chassis and it was working great again. So maybe try that? Good luck!

[bheinen74]

check/clean all the electrical connectors to the fan connector up by the radiator. mine was corroded (green), and cause no fan when i got the brat.

[Bucky92]

New Radiator...yes its grounded..2 wires to fan....the fan was working until the day it overheated...The car has a good 5+ hours of run time on it before its overheat. I am familiar with wire corrosion ( I owned an XT6 which are notorious for it) and that all has been addressed. I was in phone contact with someone while trying to narrow down the problem and we are left with thermosensor switch in the Rad and/or the relay. He just couldnt remember which relay it was.

 

Since I removed the AC from the cart ..if the relays are the same I can try Garys idea and swap them around. Or I can just do what I usually do...and direct wire the fan to run the whole time.

 

For those who havent followed...The motor was pulled..completely resealed..new head gaskets ( the whole reason for pulling the motor). I also installed new oil pump, water pump, hoses, OEM T Stat and as stated Radiator. So basically the cooling system is completely fresh. And up until a couple weeks ago it was staying nice and cool. I thought it was a loose belt which I tightened today.

 

The bubbles are not there until the motor is warm and the T stat opens up and they were not there before the overheat a couple weeks ago. I am going to try and retorque the heads even though I used the gaskets you dont have to re-torque..followed FSM and then torqued 10 lbs over by the advice of a couple people.

[Frank B]

Let it run a bit more and see if the bubbles go away, with it just idling the coolant isn't flowing enough to push the air out. It probably isn't bubbling untill it warms up because the thermostat hadn't opened up to let the bubbles out.

Hopefully!

[hatchsub]

If its the thermo switch i got one sitting on my desk. Its known good. Yours if you need it. It sounds like that to me. Its 26 years old. Then again the one i have is too...but has less miles on it.

[TomRhere]

Two things I know to check;

 

Make sure there is a short length of wire running from the top crossbar of the radiator to the radiator support. That is what grounds the radiator, in turn grounding the thermoswitch for the fan. Could've lost connection there.

 

Check the plug that goes to the thermoswitch. The one on my '82 was loose fitting, and would loose contact at times. Little squeeze with some pliers made it fit better.

 

One thing to try. Unplug the wire at the thermoswitch, run a wire from the connector to battery -, key "on" fan should run.