[mustanghead]

i have a 94 stang and when i turn on the a/c the car runs hot and fans will not turn on it would be nice to pinpoint this problem and end it soon for the car is black and its very hot with no a/c

[list][/list]

[dcraig8]

take your fan relay out.. put a jumper wire(a piece of safety wire will do) between the power and ground contacts where the relay plugs in. if your fan does not come on right away, its time for a new one. if it comes on then your relay will probably need replaced

[mustanghead]

thanks for the advice i'll go give it a try right now

[ryanw]

the same thing was going on in 2 of my work trucks , it was the fan relay

[nolife]

Do not jumper across the "power" and "ground" contacts, you will blow something up. I am not familiar the wiring on a 94 so I can not reference specific wires but you will need to jumper across the contacts that supply power to the fan and those are not called the power and ground contacts. Think about that, power is a power source, ground is ground. If you put a jumper across those, you are putting the voltage source directly to ground through a wire. You need to find out exactly which two wires to jumper across before you do it.

[Arrest Me Red]

you need more than likely a new pigtail harness... same problem with my friends we fixed last night... although could be something else but there is an option. good luck and let me know if you figure any other querks about it

[94' Cobra 351]

Originally Posted by nolife Do not jumper across the "power" and "ground" contacts, you will blow something up. I am not familiar the wiring on a 94 so I can not reference specific wires but you will need to jumper across the contacts that supply power to the fan and those are not called the power and ground contacts. Think about that, power is a power source, ground is ground. If you put a jumper across those, you are putting the voltage source directly to ground through a wire. You need to find out exactly which two wires to jumper across before you do it.

Bah hum bug! Your battery has two leads, a power and a ground, the ground just completes the circuit. If you jump those two wires it should turn on. All you are doing is bypassing the relay.

[Stangzilla]

Originally Posted by 94' Cobra 351 Originally Posted by nolife Do not jumper across the "power" and "ground" contacts, you will blow something up. I am not familiar the wiring on a 94 so I can not reference specific wires but you will need to jumper across the contacts that supply power to the fan and those are not called the power and ground contacts. Think about that, power is a power source, ground is ground. If you put a jumper across those, you are putting the voltage source directly to ground through a wire. You need to find out exactly which two wires to jumper across before you do it. Bah hum bug! Your battery has two leads, a power and a ground, the ground just completes the circuit. If you jump those two wires it should turn on. All you are doing is bypassing the relay.

He is right its no different than jumping the starter relay under the hood when it fails. I know I have done it once or twice over the years in some Fords I have owned. It wont hurt nothing you are just making your own switch with the two wires. All the relay does is use a low voltage signal from the water temp sensor and it energizes a little coil in the relay closing the contacts turning on the fan. No biggie.. :lala

[neverfastenough1]

Originally Posted by Stangzilla Originally Posted by 94' Cobra 351 Originally Posted by nolife Do not jumper across the "power" and "ground" contacts, you will blow something up. I am not familiar the wiring on a 94 so I can not reference specific wires but you will need to jumper across the contacts that supply power to the fan and those are not called the power and ground contacts. Think about that, power is a power source, ground is ground. If you put a jumper across those, you are putting the voltage source directly to ground through a wire. You need to find out exactly which two wires to jumper across before you do it. Bah hum bug! Your battery has two leads, a power and a ground, the ground just completes the circuit. If you jump those two wires it should turn on. All you are doing is bypassing the relay. He is right its no different than jumping the starter relay under the hood when it fails. I know I have done it once or twice over the years in some Fords I have owned. It wont hurt nothing you are just making your own switch with the two wires. All the relay does is use a low voltage signal from the water temp sensor and it energizes a little coil in the relay closing the contacts turning on the fan. No biggie.. :lala

Wait which one is right before I say something?

[Stangzilla]

Me.. It wont hurt if he just jumps the wire 4 a sec to see if the fan works..

[neverfastenough1]

Originally Posted by Stangzilla Me.. It wont hurt if he just jumps the wire 4 a sec to see if the fan works..

Ok I will assume you are saying Nolife is right then since you used the starter relay as an example. When you jump the starter relay you are jumping the positive to positive essentially omitting the relay. Same for the fan relay. If you jump the positive to the negative I do not see where that is omitting the relay. The positive is connected inside the relay by a coil like Zilla said to the negative. If the coil is not energizing, you can hook the positive to the negative all day and it won't energize that coil to pull that switch to turn on the fan. I say like Nolife said you jump the battery in to the hot out to the fan on the relay, omitting the relay. If the fan comes on the relay is bad, if it does not come on then the fan is bad. I just don't comprehend the hooking the positive to the negative and sending the power strait to the body. Maybe I just do understand what he was saying though. I get like that a lot.

[nolife]

Maybe I was just being anal but I was trying to prevent someone from getting confused by the details.

Way back when, someone stated to bypass the relay, jumper across the positive and negative wire. I think they meant to say to jumper across the switched part of the relay which is NOT called the "positive and negative", if anything, it would be called the "line and load" lines or the "switched leads". That may seem like a small detail but I had visions of someone looking at some wiring diagrams or a test light, seeing a positive and negative and thinking that jumpering across + and - was how you bypassed and tested relays. Zilla, i was not questioning the concept of actually jumpering around the relay for testing, just the method given for how to do it. There is nothing wrong with bypassing a relay for testing. I know a lot people know how to bypass a relay but for those that have not done it, using + and - as stated would cause very bad results. Put a jumper across the + and - terminal of your battery and see Like I said though, I know the person did not really mean to say the + and - lines and I was trying to clear up potential confusion, in reality, I may have caused more.

[Stangzilla]

Yeah you got it. I think we were all a bit confused a bit.. lol..