GMPP Harness with Vintage Air and Dual Electric Fans??

[badazz81z28]

That diagram does not look correct to me. The compressor activation wire coming from the VA controller goes to the trinary switch through it and to the compressor. The Trinary switch also acts as the ground to engage a relay for the fan. One of the trinary switch wires goes directly to ground. What doesn't look right, the "AC Switch" Should be ground. So where is the AC Switch wiring going? The Trinary switch is measuring pressure and activating as required such it will activate fan or disengage the compressor if pressure get too high.

The wire coming off the ECM is a grounding signal, not 12v+, and the blue going into the trinary is not 12v+ for the fan activation. Its for the clutch activation. All those wires headed to the fan relays should be switched grounds not power. That drawing is all wrong....


I wouldn't be too worried to run fans without a pwm. The one fan or both fan activated is how its been done for many years and such on a lot of todays cars. Granted a PWM fan speed set-up is slick and only gives whats needed, but this set-up will not kill an alternator.

[dhutton]

Deleted.....

[dhutton]

The wire coming off the ECM is a grounding signal, not 12v+, and the blue going into the trinary is not 12v+ for the fan activation. Its for the clutch activation. All those wires headed to the fan relays should be switched grounds not power. That drawing is all wrong....

Pretty sure that blue wire from the ECM is the blue fan power wire from the Connect and Cruise fuse/relay box and is the relay controlled 12V fan power. It is not the ECM fan relay control signal.

That being the case I think the diagram is probably OK.

This post is subject to mandatory forum fact checking.....

Don

[DT69Cam]

Pretty sure that blue wire from the ECM is the blue fan power wire from the Connect and Cruise fuse/relay box and is the relay controlled 12v fan power. It is not the ECM fan relay control signal.

That being the case I think the diagram is probably OK.

This post is subject to mandatory forum fact checking.....

Don

In Deed

[badazz81z28]

Pretty sure that blue wire from the ECM is the blue fan power wire from the Connect and Cruise fuse/relay box and is the relay controlled 12v fan power. It is not the ECM fan relay control signal.

That being the case I think the diagram is probably OK.

This post is subject to mandatory forum fact checking.....

Don

The single heavy gauge wire coming out of the fuse box is 12v power to go DIRECTLY to the fan, NOT to a relay like the diagram is showing. That picture shows that power wire going to the relay when in fact the small wire coming from the ECM goes to the relay which is all wired internally to the fuse box. Now you could use that heavy gauge wire to be the power supply to provide 12+ to a external set of relays to power 2 fans. However then the diagram would have to address that power going to the trinary switch (because a ground signal comes from that) AND the single 12-14ga wire would not be adequate to power 2 fans. The OP needs to add another relay to the fuse box and wire another power source out. I have each fan powered by a 10ga wire and the source coming into the box is a single 6ga. That set-up with the trinary switch fixed would probably pop the 30amp fuse in the fuse box when both fans powered up.

[dhutton]

The single heavy gauge wire coming out of the fuse box is 12v power to go DIRECTLY to the fan, NOT to a relay like the diagram is showing. That picture shows that power wire going to the relay when in fact the small wire coming from the ECM goes to the relay which is all wired internally to the fuse box. Now you could use that heavy gauge wire to be the power supply to provide 12+ to a external set of relays to power 2 fans. However then the diagram would have to address that power going to the trinary switch (because a ground signal comes from that) AND the single 12-14ga wire would not be adequate to power 2 fans. The OP needs to add another relay to the fuse box and wire another power source out. I have each fan powered by a 10ga wire and the source coming into the box is a single 6ga. That set-up with the trinary switch fixed would probably pop the 30amp fuse in the fuse box when both fans powered up.

You can energize a relay coil with a relay which is what is being done here. The trinary switch can be used to switch ground or 12 volts. In this case it is supplying 12 volts on the blue wire pair of contacts. It is also switching 12 volts on the black/green pair...

Still pretty sure that it works as drawn subject to mandatory forum fact checking sign off....

Don

[badazz81z28]

I guess if you want to push power through the trinary to power the relay. At your own discretion, just my 2 cents here.

[icemanrd19]

Just text me and I'll send you the instructions for the pcm of nc idea. I thinkni even have how I wired mine up.

9728148824

[dhutton]

I guess if you want to push power through the trinary to power the relay. At your own discretion, just my 2 cents here.

Power to energize a relay coil is low. Probably lower than the compressor clutch which is also powered through the trinary switch. The fan power is not passing through the trinary switch. Trust me on this. I spent 35 years designing electronics hardware...

BTW, I still don’t advocate the use of this solution due to its single fan speed.

Don

[badazz81z28]

Here comes the resume....then you know the wiring is more complicated then it has to be and the signal from the ECM is a ground. The diagram is marked “ECM” not the fuse box.

All that needs to be done is a second circuit and relay added to the fuse box and use the trinary as the ground switch. That will eliminate a lot of the extra wiring and Relay,

[dhutton]

Here comes the resume....then you know the wiring is more complicated then it has to be and the signal from the ECM is a ground. The diagram is marked “ECM” not the fuse box.

All that needs to be done is a second circuit and relay added to the fuse box and use the trinary as the ground switch. That will eliminate a lot of the extra wiring and Relay,

It also says 12 volts and the photo at the top of the thread clearly shows the fuse box and blue 12 volt fan power lead. The thread also references the GMPP harness specifically. Is the signal you are talking about even pinned out on the GMPP bulkhead?

Your proposed solution only enables both fans if the AC is on if I am following you correctly. I personally would prefer a solution that would allow both fans to turn on regardless of the state of the AC. A simple diode OR etc would get you there....

Anyway, post up your credentials. I’m sure they are badazz....

Don

[DT69Cam]

Here comes the resume....then you know the wiring is more complicated then it has to be and the signal from the ECM is a ground. The diagram is marked “ECM” not the fuse box.

All that needs to be done is a second circuit and relay added to the fuse box and use the trinary as the ground switch. That will eliminate a lot of the extra wiring and Relay,

Gonna have to agree with Don on this one. I don't know of any ECM's with a single blue wire coming from them. I would second that is the Blue wire next to the Fuse box on the GMPP harness.

[icemanrd19]

How the hell is this thread still going on? Seriously it's simple. My fans kick on with high and low settings, with the ac, with the engine temp and even turn on and off based on speed.

What more do you need?

[badazz81z28]

Gonna have to agree with Don on this one. I don't know of any ECM's with a single blue wire coming from them. I would second that is the Blue wire next to the Fuse box on the GMPP harness.

I'm not getting caught up on the color of the wire shielding, I'm more concerned with the power sources and grounds.

For reference I have the GMPP harness and VA and have the fans wired together with a trinary. So I have been there....done it.


There are two fan activation wires coming from the E67 ECM to the GMPP fuse box. They are both spliced together at the fuse box and run into a single relay to run a single fan. The Fuse box itself has two large gauge wires coming from it (one for the fuel pump and the other for the fan). These are relay powered activated 12+ sources. You could use that fan power source to energize another set of relays, but then you have a relay circuit powering another relay which creates too much mess. Now the OP has two external relays outside the fuse box, wires coming from the battery and then to the fans. That's a lot of unnecessary wires.

The GMPP fuse box has capacity for more relays and fuses. Add another relay and fused circuit. Then just wire the trinary as a ground activation to pin into the fuse box relay or splice into the ECM wires. The whole set-up will require much less wiring and be cleaner.

Take it FWIW, I’m done.

[dhutton]

How the hell is this thread still going on? Seriously it's simple. My fans kick on with high and low settings, with the ac, with the engine temp and even turn on and off based on speed.

What more do you need?

Entropy fan controller works too. So does the DCC pwm controller. There are many solutions in addition to the one you used. Each one has its pluses and minuses...

Point is someone stated that a previously proposed solution does not work when in fact it does. This lead to a lively debate...

Don

[dhutton]

I'm not getting caught up on the color of the wire shielding, I'm more concerned with the power sources and grounds.

For reference I have the GMPP harness and VA and have the fans wired together with a trinary. So I have been there....done it.


There are two fan activation wires coming from the E67 ECM to the GMPP fuse box. They are both spliced together at the fuse box and run into a single relay to run a single fan. The Fuse box itself has two large gauge wires coming from it (one for the fuel pump and the other for the fan). These are relay powered activated 12+ sources. You could use that fan power source to energize another set of relays, but then you have a relay circuit powering another relay which creates too much mess. Now the OP has two external relays outside the fuse box, wires coming from the battery and then to the fans. That's a lot of unnecessary wires.

The GMPP fuse box has capacity for more relays and fuses. Add another relay and fused circuit. Then just wire the trinary as a ground activation to pin into the fuse box relay or splice into the ECM wires. The whole set-up will require much less wiring and be cleaner.

Take it FWIW, I’m done.

I don’t think anyone is saying what you did does not work. I think the issue was when you said that the previously posted solution was all wrong. I don’t think that is the case....

Don

[icemanrd19]

Find blue and green 18g going to pin a9. Cut the blue wire going to pin a9. Crimp two pin blue wire to the harness.

Install 1 blue pin in c4 and the other into d3
Install red 12g wire between pin c6 and m3. The wider pin goes into m3
Install orange 18g wire Y harness into d6, L6, and c1
Install white 12g wire in slot d4 and d2.
Install black 12g wire into d1
Install brown 12g wire in c3
Add 10amp and 40 amp fuse into corresponding to l6 and m3



Wire fans
Gmpp original fan control blue 12g wire will go to fan 1 positive
The brown 12g wire will go to fan 1 neg
The white 12g wire goes to fan 2 positive
Black 12g wire will go to fan 2 neg

[1low65]

Will it affect operation if I do not use the blue wire from the connect and cruise harness?? also how do I connect to a binary switch? everything I can find talks about a trinary switch

[icemanrd19]

I used the binary switch.

[badazz81z28]

Will it affect operation if I do not use the blue wire from the connect and cruise harness?? also how do I connect to a binary switch? everything I can find talks about a trinary switch

That’s because if you want fan activation you need a trinary switch. The binary switch will only kill the compressor with damaging pressures situations.