No Aux fan with A/C or by temp....can I swap ABS relay to test?

[solomon7]

It does not look like the one on the right.

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It's what NAPA gave me. It LOOKS just like the other relays in the PDC, but has a diagram and pins numbered 1-5 instead of 85 86 etc.

 

[solomon7]

Here's the pins. In order from right upper clockwise: 1, 4, 2, 3, and the center one is 5.

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The stock relay is numbered correspondingly: 86, 87a, 85, 30 and center is 87.
I just want to make sure I'm clear on what pin does what so I can make sense of the wiring diagram better.

I can't seem to figure this out, but I'm tryin'!

BTW how would i test the signal wire?

?????

 

[Digger87xj]

The two terminals you need to do all your checking on are the two that in the socket that line up with the terminals that are in the vertical position in your pic. #3 and #5

One is 12v supply that comes from the fuse.(#3 on the relay) With a good fuse, there should be 12v there.

{on a side note, just because there is 12v there does not mean the (entire) circuit is viable enough to carry a load (amperage) Corrosion inside of a wire or in a connection can become bad enough to not allow the circuit to carry a load, but good enough that is will carry 12v for a meter to measure.}

The other connects to the fan. (#5 on the relay)

The diagram shows how the relay electrically sits when it is off. The "bar" flips from 3-4 to 3-5 when it turns on, feeding voltage to the fan.

check between the socket for pin 5, to ground with the fan disconnected. should be infinite. If it is not, there is a short to ground. That is no bueno. that needs corrected.

You can jumper the two socket terminals with a piece of 14ga wire... with the fan disconnected, nothing should happen. If the fuse blows there is a short. That's no bueno, that needs corrected.

Now, if all is well so far,
Witht he jumper wire installed, connect the fan connector back together. it should turn on.
If not, either the ground is bad or the fan is bad.
If the fuse blows, the fan is bad.

To check the ground disconnect the fan. on the body side of the connector check the black wire with the ohm meter to ground. should show .5 ohms or less

If the ground checks ok, the fan is likely bad.
If you get infinite, that is no bueno and needs to be fixed.

You can check the capability of the circuit to carry a load, you can use a headlamp and connect it with wires to the body side of the fan connector. With the jumper wire installed it should light. if it is dim or doesn't light, then the circuit has corrosion somewhere. that is no bueno. It needs to be fixed

 

[Digger87xj]

My bets are on a faulty fan.

 

[solomon7]

You can jumper the two socket terminals with a piece of 14ga wire... with the fan disconnected, nothing should happen. If the fuse blows there is a short. That's no bueno, that needs corrected.

SO I'm clear , Do I jumper 3 to 5 with fuse installed, then test with car off, or turn key to on then test?

 

[Digger87xj]

3 is Hot all times. Yes with the fuse in. Have a few spares handy. You can use lower amp fuses for testing purposes.

 

[Digger87xj]

The two terminals you need to do all your checking on are the two that in the socket that line up with the terminals that are in the vertical position in your pic. #3 and #5

One is 12v supply that comes from the fuse.(#3 on the relay) With a good fuse, there should be 12v there.

{on a side note, just because there is 12v there does not mean the (entire) circuit is viable enough to carry a load (amperage) Corrosion inside of a wire or in a connection can become bad enough to not allow the circuit to carry a load, but good enough that is will carry 12v for a meter to measure.}

The other connects to the fan. (#5 on the relay)

The diagram shows how the relay electrically sits when it is off. The "bar" flips from 3-4 to 3-5 when it turns on, feeding voltage to the fan.

check between the socket for pin 5, to ground with the fan disconnected. should be infinite. If it is not, there is a short to ground. That is no bueno. that needs corrected.

You can jumper the two socket terminals with a piece of 14ga wire... with the fan disconnected, nothing should happen. If the fuse blows there is a short. That's no bueno, that needs corrected.

Now, if all is well so far,
Witht he jumper wire installed, connect the fan connector back together. it should turn on.
If not, either the ground is bad or the fan is bad.
If the fuse blows, the fan is bad.

To check the ground disconnect the fan. on the body side of the connector check the black wire with the ohm meter to ground. should show .5 ohms or less

If the ground checks ok, the fan is likely bad.
If you get infinite, that is no bueno and needs to be fixed.

You can check the capability of the circuit to carry a load, you can use a headlamp and connect it with wires to the body side of the fan connector. With the jumper wire installed it should light. if it is dim or doesn't light, then the circuit has corrosion somewhere. that is no bueno. It needs to be fixed

I missed a step.
Check continuity (ohms) from the socket for pin 5 to the green wire in the body side of the fan connector. It should be .5 ohms or less.

 

[Hypoid]

Wow, I doze off after dinner and look what happens. Thanks Don! :thumbup:

 

[Digger87xj]

Well? What was the outcome?

 

[solomon7]

Sorry guys. Been working 7 a week and have only come home to sleep lol.

Finally tracked it down, following the above advice. Chased it for a while and as best I can tell I have a dying fan motor. there's a short in a wire when the harness wiggles.
I've found a new harness and wired it in, and now have to source a fan.

This should fix it but I REALLY won't know till I find a fan.

Thanks so much to Hypoid, yossarian, and Digger for the detailed and VERY patient advice.

Ya'll are represent the spirit of what is all about!
I hope I can be as helpful to others in the future. :cheers: