The car was overheating when it was going slow and at stop lights. I noticed the radiator fan was not working. I have replaced the fan relay switch, and I have switched the radiator fan. I have jumped the fan and it does work. The fan still will not come on when it gets warm. I have tested the plug to the fan and I do have voltage, but it was low, 1 time (less than 5)and the other time it was over 11.
I did notice that when the a/c was switched on the fan does not work either, and there was no voltage at all. The a/c does not work, but the light comes on when you push the button.
Is there a relay switch for the a/c part of the fan, or did the parts guy give me the wrong relay? there are 4 relays and I am not sure which one is the fan relay.
I am lost and do not know what to do next. Any help would be greatly appreciated.

Thanks,

Jim

 

You may need a new engine temp sensor. This is the sensor that actually turns the radiator fan on when needed.

Do the fans come on when you turn the A/C on? If not, then it is the wrong relay, or bad wiring between the battery and fan.

 

I have the same car.

What is your definition of overheating? I am familiar with the temp gauge. Where was the indicator pointing before you pulled up to the light and what does it get to sitting at the light?

What temperatures were outside?

When you jumpered the fan to stay on during a long enough test run...does the temp gauge come down to where it should be at?

Your car has two temp sending units. One is an ECU (for emission controls) unit at the thermostat, and the other one is to the left into the block with one wire coming off it and this is for your temp gauge.

You might want to check out my post in Chats and Whines forum here.

Oh...and have you invested in say a Haynes manual for your car? I have that and also went to the library to run photocopies out of the Mitchell's wiring diagram book for my entire car. That way you coud trace back the entire wiring from your fan.

But you have to be sure that your ONLY issue is your fan. And you do not want these aluminum head engines on cast blocks to run hot, as they are good for blowing head gaskets. Be sure you keep 50/50 coolant in it with good pressure cap as this will raise the boiling point of the coolant to about 265 degrees, which could actually help you from blowing a gasket in borderline overheating cases. It is not good to have water start boiling in the engine.

 

the car runs normal temp until you start the stop and go at the stop lights or if you let it sit idling. The fan does not come on when it gets warm. The needle goes up th the H, but i stop the car before it gets too hot.
I did the head gasket a few years ago.
I do have the haynes manual, but it does not show which relay is for the fan.
I just jumped the fan to make sure it was working.

Is there a way to test the sensor?Which one should I check?

Thanks,

Jim

 

Go to the parts store and ask to see a new fan relay. Then compare what you saw with how the terminals are...the number of them and the orientation of the spades...of the 4 or 5 similar looking relays on your fenderwall under your hood. That would be the easiest thing I coud think of, short of stripping the wire harness sheathing so you can physically trace wires-colors from the fan motor.

If I have a chance today, I will try to see if I can find out more by looking in MY wiring diagrams.

 

I have a '89 4 cyl. and I have never had the fan come on. The only time it has was when it overheated. The theromstat was stuck.

 

videobruce,

On your 89, what kind of car was it? My 91 Spirit car now has a brand spanking new radiator and MY fan will come on...and it's not even hot out yet, when the car sits and idles. And I haven't even put the thermostat back in yet (tomorrow?).

Maybe yours SHOULD be coming on. ? Maybe your temp gauge ain't right and it's getting hotter than you think. ? Maybe they over-radiatored your particular car. ?

 

You need to find out which relay controls your fan motor. The relay should be the absolute last stop before the fan...meaning that if nothing else you should be able to trace the wires from your fan motor directly to the relay that controls it. Normally the fan should come on when you turn on your A/C, but that is not true in all cases...especially if your A/C is not in working condition. Some vehicles kick the fan on when the A/C high side pressure gets above a certain PSI....so if there is no freon in your A/C system or if the switch that measures the high side pressure is not working then it may not turn the fan on when you turn on the A/C.

The computer SHOULD, however, even if your A/C does not work, turn the fan on when the computer gets a signal from the engine coolant temperature sensor (not to be confused with the coolant temperature sending unit which controls your guage) that the engine is above normal operating temperature....which usually will happen at an idle with the vehicle stopped.

When the computer senses that the engine is too hot it will send a ground signal to the cooling fan relay which in turn sends power to the cooling fan motor. Once you find the cooling fan relay you will notice that it should have two small wires and two big wires going to it (unless it is in a relay box where you can't see the wires). Using a test light with the relay unplugged, verify that you have battery voltage on one of the big wires going to the relay, the other big wire should be a ground. If you do...use a paper clip and jump across the two big wires and if the fan kicks on then you know your wiring from the relay to the fan motor is good.

If all that checks good then test the two small wires going to your relay. One should have voltage on it with the key on, the other should have a ground signal coming from the computer ONLY when the engine temperature is hot enough that the fan needs to kick on...the temperature at which this happens varies by vehicle, but it is usually somewhere between 212 and 230 degrees.

Do all that and then tell me what you find and I will let you know where to go from there.

Joe

 

Just a thought, but on a 16 year old Spirit, I might be inclined to wire the fan/relay to come on with the ignition and simply run all the time; that's how I have the aux fan wired on my wrecker (main fan is engine driven, of course). Running too COOL is likely to be less problematic than risking an overheating and doing the bad stuff daveboy alluded to.

 

You stated you jumped the fan. Did you hot wire it with 12V straight from the battery ?
I would establish that you have a working fan motor and as HotinOKC stated, you may need a temp sensor.
If your A/C charge is too low the fan will not come on so this would not be a good test especialy given the age of the car.

And welcome back DaVeBoy ! how was your vacation ?

 

Mackey,

I'm not sure how this works exactly regarding what you said about the fan not coming on if the a/c is not running...but with my 91 Spirit, I have the a/c compressor unit yanked right out and the lines to the evaporator (which I intentionally left in front of the radiator for radiator fin protectioon) are open...yet MY fan works as it should.

Maybe regarding what you said there are other circumstances involved that you might need to clarify?

 

I was thinking in terms of just when the A/C unit is activated but the fan functioning normaly for cooling without the A/C.
OK........ now I'm confusing myself.
OK......what I mean is with most cars when you turn on the A/C the electric fan will run even if the temp sensor does not call for the fan to activate, it overrides the temp sensor so if there is not enough R34 in the lines the fan and the A/C shouldn't come on unless the temp sensor calls for it.
Whew!........does that make any sense ?

 

I knew what you meant, Mackey.

 

Ok, I got the fan to work, but it is intermittent. Either I have a bad relay(it is new from NAPA), or I have a short in the wirirng. The fan will come on one time, and the next time it might not. I can tap on the relay and it goes out. I tap it again it comes back on. I move the wires it does the same thing.
What will be the best way to narrow the problem?

Thanks,

Jim

 

There maybe a corroded/bad connection within the relay box. The wires feeding the actual relay may have come loose causing your problem.

You need to seperate half the relay box so you can get access to the wires.