GMPP Harness with Vintage Air and Dual Electric Fans??

[GEARBOXGARAGE]

Perhaps this has been discussed in the past but I seem to get multiple answers on this issue without much clarity. We are running the 525 LS3 package using the GM harness, which has one output for an electric fan (Blue Wire on the GM harness pic) but we are running dual electric fans on our Be Cool setup and also need to integrate the trinary activation from the Vintage Air unit. Does anyone have a proven wire schematic on how to make the connections so the GM computer can activate the dual fans, plus work together with the trinary from the VA? The blue wire on the GM harness is relay triggered, but I believe its load rating will only support a single electric fan. Any help would be appreciated.

[DT69Cam]

Mike, I will be using the stand alone Entropy fan LSX controller to activate my dual fan set-up. I will NOT use the GMPP blue wire because the fan is set to come on at around 207*. Another reason for me is the GMPP fan set-up only has a HIGH speed and eventually may cause alternator failure ( too much amp draw) IMHO. Check out, http://www.entropyrad.com/lsx-series...ontroller.html

[dhutton]

I think you are going to find a single speed fan solution to be quite noisy. There are better options like the Entropy two speed controller above or the DCC pwm controller among others.

Don

[parsonsj]

You've got a big ask here.

Several of us have been through this in great detail. Give this thread a try (search is your friend): https://www.pro-touring.com/threads/...fan-controller

[badazz81z28]

Both fan activation wires are spliced together in the fuse box. You can separate them and add another relay in the box. It’s a little difficult because the contacts are hard to source. I used wires from another fuse box I got from the junk yard. The trinary switch has a ground wire activation for the fan. All you need to do is splice that wire into the harness fan ground activation wire or both in the harness. BTW with HP tuners, you should be able to lower the fan temps.

[icemanrd19]

Search my thread. It's very easy

After you read that call pcm of nc and get their ac bump and gmpp ac kit. Few wires go into the gmpp box, flash the ecu and you are done.

[andrewb70]

Both fan activation wires are spliced together in the fuse box. You can separate them and add another relay in the box. It’s a little difficult because the contacts are hard to source. I used wires from another fuse box I got from the junk yard. The trinary switch has a ground wire activation for the fan. All you need to do is splice that wire into the harness fan ground activation wire or both in the harness. BTW with HP tuners, you should be able to lower the fan temps.

Those boxes are pretty standard Delphi issue. I am sure Mouser has the needed contacts.

If it was me, I would definitely opt to convert to pwm operation and run the fans simultaneously, but vary the speed according to A/C pressure and engine temp. JP has run into issues doing this with the GMPP e67 ECUs, but he did resolve it eventually.

Andrew

[icemanrd19]

Again this works like a charm

http://www.pcmofnc.com/product/gmpp-...ric-fan-kit-3/

http://www.pcmofnc.com/product/hot-r...-bump-circuit/

[badazz81z28]

^^^looks to me the kit is the commercial version of what I did myself.

[badazz81z28]

Those boxes are pretty standard Delphi issue. I am sure Mouser has the needed contacts.

If it was me, I would definitely opt to convert to pwm operation and run the fans simultaneously, but vary the speed according to A/C pressure and engine temp. JP has run into issues doing this with the GMPP e67 ECUs, but he did resolve it eventually.

Andrew

I looked, I couldn’t find them plus it’s hard to identify what you exactly need. If someone has a link by all means.

[DT69Cam]

I have heard excellent results with the PCM of NC kit. For me, 95.00 for the PCM of NC kit, Entropy kit is 160.00. Entropy is a little more but no flash is needed and you can change temp settings anytime you want without touching the ECM. . It is plug and play. Just sayin.

[andrewb70]

I looked, I couldn’t find them plus it’s hard to identify what you exactly need. If someone has a link by all means.

Pretty sure the GMPP relay/fuse center is on page 7.19 of the Delphi Global Catalog. The terminals for the relays are MetriPack 280 series "tangless."

http://www.powerandsignal.com/docs/D...%20Catalog.pdf

[dhutton]

I have heard excellent results with the PCM of NC kit. For me, 95.00 for the PCM of NC kit, Entropy kit is 160.00. Entropy is a little more but no flash is needed and you can change temp settings anytime you want without touching the ECM. . It is plug and play. Just sayin.

The Entropy also includes the AC fan bump, which is another $42 from PCM of NC. It also includes heavy gauge power cables for the fan and battery connections.

Don

[badazz81z28]

Pretty sure the GMPP relay/fuse center is on page 7.19 of the Delphi Global Catalog. The terminals for the relays are MetriPack 280 series "tangless."

http://www.powerandsignal.com/docs/D...%20Catalog.pdf

thanks I’ll take a look. All the pins should be tanged to lock into the fuse block.

- - - Updated - - -

Pretty sure the GMPP relay/fuse center is on page 7.19 of the Delphi Global Catalog. The terminals for the relays are MetriPack 280 series "tangless."

http://www.powerandsignal.com/docs/D...%20Catalog.pdf

thanks I’ll take a look. All the pins should be tanged to lock into the fuse block.

[130fe]

I have a NIB pcmofnc fan add kit plus the bump kit I did not use. Let me know if you are interested in it. I ended up using the entropy setup, works great but your charging system better be good. Those Entropy fans draw some current ;-). Those fan definitely draw some air!

[GEARBOXGARAGE]

A lot of good information here. Thanks everybody for the input! Here is also a rough schematic that was sent to me from C&R Racing Tech Support and also confirmed by Vintage Air Tech Support. It uses a 12v+ 5amp fused signal through the trinary and splices in with the blue activation wire from the ECM. They said they have used this set-up multiple times with no issues. I would imaging that it would also work with the Derale pwm in place of the relays if fan noise was an issue or if the charging system wasn't up to a full draw from the fans. We are using the Vintage Air Front Runner with a 170 amp alternator which should be more that enough to take the full hit of dual SPAL fans. Have any of you guys seen something similar to this set-up? The Tech guy at C&R said that his friend works at Detroit Speed and they pretty much do the same set-up, except they just add the relays inside the GM fuse box to keep everything factory looking and a cleaner package.

[dhutton]

It will work but will be loud. I would not do it that way.

Don

[GEARBOXGARAGE]

It will work but will be loud. I would not do it that way.

Don

Don, do you say you would not do it because of the noise issue and fans only running at 100%?

[dhutton]

Don, do you say you would not do it because of the noise issue and fans only running at 100%?

Yes and yes.

Don

[DT69Cam]

Not to mention you will be blasting that alternator with amp draw every time they come on (100% speed) instead of a 2 speed or a pwm controller.