89Formula5.0

Ok, its an 89 Formula 350 TPI.

PROBLEM: Car overheats in traffic, and gets hot on the freeway and nears overheating ......

So far, i have flushed out the coolant and refilled it with new fresh coolant; replace thermostat to 180¯F; checked the motors on the fans by energizing them directly, both work; replace water pump with a new one; and checked the relays.

Relays are part# 14089936 with a 9006 number above.

It is a 5 prong relay with the hot wire prong in the center. Then there are 2 prongs on each side of the hot prong. Should both relays work the same? Both relays receives 12v. So there are no breaks in the wiring..... thank g0d!:hail: Now when I put a lead wire onto the hot prong and to my multimeter, and another lead wire to the ground or neg prong i get the 12v, but as soon as i put a load on it (I.E. a fan, either of the fans for that matter.) the voltages drops to less than 2v. What gives?
I don't know where the fan switch(es) is located...... i have read in here that it is somewhere on the passenger side of the head. I wish i had a scanner to upload pics of the relays, how i tested the relays, and when the relays receive the 12v, and finally when it has those 12v and falls below 2v when i add a fan.

I am going to connect the fans directly for a while until i figure out this mess. I am also going to have the Rad cap checked out to see if it is still any good. The Radiator has been flushed clean, tested for pressure and seems to be in very good condition. I might end up buying an Aluminum one soon though.

If anyone might have some input on those relays, or if someone has had this problem; please respond. Thanks for taking the time to read through it all...

BillD91RS

I do have some experience with an overheating camaro. About a year's worth actually. I replaced my water pump, radiator, fan everything I could think of.

Are the fan's coming on when the engine gets hot? Do you have AC on your car? When your AC is on it should turn the fans on too. Thats what I eventually had to do. Just something you might think about

Bill

GKK

Start with the basics first, Is the Coolant Mix 70% Water and 30% Antifreeze, Is the rubber Air Dam in place, If you have A/C switch it on and one of the fans should automatically turn on. clean all the debri from the front of the radiator. Here is a picture of my Jet Fan Switch.

Danno

The relay has five connections, but only 4 of them are used. Look at the plug and you will see two heavy wires and two thinner wires. Unplug the relay and with the engine off and a DVM measure from the heavier wires to ground. One of the heavy wires should have 12volts, the other one nothing. Those two heavier wires are the contact side of the relay, or the ones that feed voltage to the fan motor. When the relay closes the 12 volts from the feed wire(heavy orange most TG's) goes through the relay contacts when the relay energizes and turns the fan on. The lighter guage wires are 12 volt feed to the coil side of the relay and the coil ground line which go to the ECM(primary fan) and fan switch and AC pressure switch(secondary fan). In dual fan setups the ECM turns on fan1. One of the lighter guage wires will have 12v with the key on(relay still unplugged) the other nothing(make note of which one is which). To test the switch wire on either plug in relay and go to the lighter guage wire that had 0v, it should now have 12 volts on it because the voltage is coming through the coil. Wait till it comes up to temp for fan turn on and that wire should go low1-2v and relay should energize. You can normally feel it click when this happens. If it clicks then measure the two heavier wires. Both should have 12 volts. If one side has it and the other doesn't the relay is bad. You can also demand primary fan turn on by turning on AC, or jumping the two pins on the diagnostic connector you use to get codes. Jump the pins and turn on key, don't start engine. Codes will show and primary fan should come on. The relays are a VERY common problem. GM supplies a redesigned relay that is much more reliable. You can also use the blower motor relay for testing. Also the plug can get overheated causing a poor connection to the relay. If that's the case, replace it. They are available at most auto parts stores. NAPA carries the improved version also, under #AR-279.

breathment

this might help show what Danno was saying to make it a little easier for you

Krazzycowgirl

OK, your two fans are a cooling fan and a heavy duty cooling fan.

There are two relays for these fans, one for each fan. Four wires go to each relay.
Both fans use the ORANGE wire for permanent power (straight from the battery. This is the power that will actually go to the fan.
They also have a BLACK & RED (cooling fan) or BLACK & PINK (heavy duty cooling fan) wire. This wire goes to the fan motors.
They each have a BROWN wire, this is a switched power source (turned on when the key is in anything but OFF.
The cooling fan has a DARK GREEN & WHITE wire that provides a ground when coolant temperature gets hot enough. This ground is provided by the coolant fan control relay in the ECM (computer).
The heavy duty coolant fan has a GREY wire that can provide a ground either through the fan A/C pressure switch (closed for A/C operation) or the heavy duty coolant fan switch (closed when coolant temp reaches 238 degrees F).

Enough background. You probably either have a short to ground in the coolant fan relay DARK GREEN & WHITE wire or it has been wired to the chassis. Either that or the ECM is set to keep the fan on. Could be a computer malfunction.

The heavy duty coolant fan is probably not receiving a ground. It could be a bad switch, either of the switches I mentioned above. The easy way to check is just to provide a ground on the GREY wire. You can use a jumper wire. Just insert on side to the back of the relay connector, with the relay installed. With the key on, touch the other end to the chassis. The relay should click and the heavy duty coolant fan should come on. If it does, then you have at least one of the switches bad.

Good luck. If you don't already have one, I suggest getting a decent multimeter, and a Chilton's manual. The manual has wiring diagrams in it.

Dustin89GTA

I also have the same problem, and that has been the best help yet.

Thanks

Krazzycowgirl

When did I Post this???? must been my husband who hacked into my stuff lol

Cadillac

That was taken from the bottom of the engine, no?

Nice wires. :-)