Hello,

New to the site, I have a 1993 Camery 4cyl wife drove home last week and running hot.
I am tring to figure out cooling system.

I checked and tested relays and found them to be good. I did notice it was missing the main relay. Wife went to Costco and not sure if it was stolen. I talked to a few forks and they tell me some models did not have a main relay. I picked one up and installed it and got the fans to work. They didnt want to shut down so had to replace temp switch on lower side of radiator.

Now I cannot get them to come on. I noticed the bottom tank of the radiator is alot cooler that the top side and sensing this isnwhat the fan would not operate.

What would cause the lower half of radiator to run cooler that upper. Is it thermostat or water pump? Radiator is newer.

Any help greatly appreciated

 

The purpose of the fans are draw air through the radiator when the car is stopped or moving slowly such as stop and go. If moving say over 20 mph the fans would be off.

The fans activate based on coolant temp.

To test for proper function: Turn on A/C with engine running. Fans should cycle on/off when A/C compressor cycles on and off. With A/C off, let engine idle. Fans should turn on when coolant temp reaches 199F. This this main relay installed and not installed.

If the fans work OK, the issue is some place else.

This could be a plugged radiator (common), failing water pump (rare), not enough coolant in radiator (check), coolant system needs flushing (common), collapsed radiator hose (rare), failed thermostat (common).

The fan system uses the Radiator Fan Relay, Radiator Fan Relays No 1 and 2.

 

Car is running at normal temp now. What Im trying to figure out.
Why is upper part of radiator hotter that the lower. Would it be a thermost stuck open?The switch is in the bottom of the radiator and dont think its get hot enough to trigger fan.

current condition When I unplug wire from switch on bottom of radiator, both fans comes on.

If I turn AC on and start engine fan doesnot come on.

Only way I can get power to the fans is I added the missing relay that says main relay.

Not sure if someone got under the hood and took relay.

Thanks

 

If the fans work when the switch is unplugged, the relays controlling this also work. The switch should open when the coolant temp reaches 199F.

When A/C is on, the fans will only come on when the compressor is engaged. The fans will cycle on and off with the compressor on/off.

You can test the switch by removing radiator cap and warming up. When temp gets above 199F, fans should start. If not replace switch.

The easiest first step is to change the thermostat. When doing so, flush out the coolant system. When a garden hose is placed in the upper hose, water should flow out the bottom without backing up.

 

Thanks for getting back to me, I did replace switch and I dont think bottom of radiator is not getting hot enough to open and allow fan to come on. Im replacing thermostat tomorrow. I replaced radiator and water pump when I did timing belt last year.

Rick

 

Sounds good. Post back with the results.

 

Changed thermostat and new radiator cap. Car does not run hot and fans HAS NOT come on at all. Seems like bottom of radiator still a bit cooler than top. One thing I noticed is compressor on AC does not click on /off when I turn AC on. Light indicator comes on when I set to AC but nothing on compressor. I did check relay for AC and that works ok. I'll check on compressor today.

 

Light on or light on and flashing?

Radiator Fan No 3 powers the A/C magnetic clutch.

Can also be low Freon in system, the result it shuts down.

 

No check engine light flashing, only light that comes on soilid is indication on AC swicth when turned on. Now to think of it I think the compressor was making noise when clutch use to engage. That might had given up and may need to replace compressor.

 

Sometime a charge is all the AC system needs to kick back on and fans start turning. You should be able to look through a little circular glass viewfinder on one of the AC lines and see coolant inside.