Entropy Fan Issue

[Putzer]

I am having an issue with the entropy LSX radiator/fan setup. When the key is turned to "on" both fans will run on low speed. They should be receiving the trigger from my speartech harness to turn off and on at certain temps and/or when the vintage air AC is on via trinary switch. VA system is set to off and not blowing any air with key on. Any ideas as to why this could be happening?

• Green trigger=PCM Fan 1, connects to yellow wire from Entropy fan controller

• Blue trigger= PCM Fan 2, connects to VA Trinary switch

• PCM Fan 2 and green wire from entropy controller are spliced together and connect to blue wire from trinary switch

[HO455]

Lots of variables in your question. Without more information we are just throwing darts.
Can you provide a wiring diagram of how you connected all of the pieces involved? (Including the entire Vintage Air wiring)
Do you have a multimeter?

[Putzer]

Originally Posted by HO455

Lots of variables in your question. Without more information we are just throwing darts.
Can you provide a wiring diagram of how you connected all of the pieces involved? (Including the entire Vintage Air wiring)
Do you have a multimeter?

Thanks Ho. I attached some more pictures and a very rough sketch. This is my first build so I've tried very hard to make sure I do things right the first time to avoid situations like this that involve problem solving. I do have a multimeter.

Not sure how to rotate pics or why they're posting sideways; they're the correct orientation saved on my PC.

[Andy4639]

I turned the picture so I could read it.

The trigger wires all need to be grounds off of the relays not the fan grounds. The fans need the hot 12 volt source wire ran to both fans that has a rated fuse to handle them from the relays. The trainery switch should over ride the #2 fan any time the head pressure for the AC is reached.

One thing I don't like about all this is when the AC is on the electric fan is on all the time even when your driving down the road at speed. It doesn't need to be on though. It will kill the fan faster by running it all the time.

I fixed this on my 6.0 LS swap in my 71 C 10.

[Putzer]

Originally Posted by Andy4639

I turned the picture so I could read it.

The trigger wires all need to be grounds off of the relays not the fan grounds. The fans need the hot 12 volt source wire ran to both fans that has a rated fuse to handle them from the relays. The trainery switch should over ride the #2 fan any time the head pressure for the AC is reached.

One thing I don't like about all this is when the AC is on the electric fan is on all the time even when your driving down the road at speed. It doesn't need to be on though. It will kill the fan faster by running it all the time.

I fixed this on my 6.0 LS swap in my 71 C 10.

I believe that in my situation there are no relays outside of the fan controller though, right? Attached another picture of the fan controller provided by entropy.

[Andy4639]

Let me look at the new pictures they just showed up.
You need relays to operate the fans. I wouldn't run them with out them. All you instructions show relays. The first sentence on your controller states this also. I assume you should have relays.

[Andy4639]

Looks like it has the relays built in. Do you have the setting inside it right?
These instructions are different from yours????? I wonder why???

[Putzer]

Originally Posted by Andy4639

Looks like it has the relays built in. Do you have the setting inside it right?
These instructions are different from yours????? I wonder why???

The settings come preset and there’s a big sticker on the back that says “unless you’re a rocket scientist, don’t open this cover” haha

It is odd that the diagram you uploaded is different... I attached a picture of the next page showing “series or parallel “ diagram but I think it’s not the diagram I need to be looking at. Just throwing it out there at this point.

[Andy4639]

Originally Posted by Putzer

The settings come preset and there’s a big sticker on the back that says “unless you’re a rocket scientist, don’t open this cover” haha

It is odd that the diagram you uploaded is different... I attached a picture of the next page showing “series or parallel “ diagram but I think it’s not the diagram I need to be looking at. Just throwing it out there at this point.

Looking at the picture it says fan #1 out going to the #1 fan. Then it say's fan #1 in comes from the #2 fan.

Then it says fan #2 out going to fan #1 and has the ground wire grounded to the vehicle. I can't see how this will ever work.

[Putzer]

Originally Posted by Andy4639

Looking at the picture it says fan #1 out going to the #1 fan. Then it say's fan #1 in comes from the #2 fan.

Then it says fan #2 out going to fan #1 and has the ground wire grounded to the vehicle. I can't see how this will ever work.

I emailed frank at entropy this morning and he was confident that by putting a diode in the yellow wire, it would solve my issue.

[Andy4639]

Originally Posted by Putzer

I emailed frank at entropy this morning and he was confident that by putting a diode in the yellow wire, it would solve my issue.

I hope it does but I don't see how by the wiring schematic. Good luck with it.

[HO455]

I am guessing that the yellow wire is expecting to see 12+ DC or an open line coming from the A/C clutch for a factory A/C installation. When hooked up to the LSX PCM it is likely that the fan #1 trigger connection is grounded until the fan is triggered. (Something commonly done to reduce EMF and electrical noise problems) This grounding is being forwarded by the Entropy fan controller and the result is the #1 fan runs continuously. This is why installation of a diode solves the problem.
It does appear that there is a problem with their diagram. On the fan wiring harness the color coding makes sense but the labels on the fan controller drawing seem to me to be wrong. Fan 1 in and fan 2 out labels appear to be swapped. I recommend checking with Entropy to be sure. Although in may not be an issue as the wiring appears (from the quick search of the interweb I did) to be in a metripak plug and if the harness is labled correctly you would have it wired correctly. It is likely most folks would never notice it.

[MDPotter]

If I were you, I would throw out that fan controller and use a fuse block setup. A few observations:
-Fans should not be on with just the key on (engine off)
-Vintage Air should be able to override fan functions
-PCM supplies ground triggers. These grounds don't go to the grounds of the fans, but through the relays.

Attached is the GM dual fan wiring schematic with the Vintage Air trinary switch incorporated. More info on this here: http://67-72chevytrucks.com/vboard/s...d.php?t=799417

Dual Fan GM Schematic w trinary switch incorp.pdf

[Andy4639]

Originally Posted by MDPotter

If I were you, I would throw out that fan controller and use a fuse block setup. A few observations:
-Fans should not be on with just the key on (engine off)
-Vintage Air should be able to override fan functions
-PCM supplies ground triggers. These grounds don't go to the grounds of the fans, but through the relays.

Attached is the GM dual fan wiring schematic with the Vintage Air trinary switch incorporated. More info on this here: http://67-72chevytrucks.com/vboard/s...d.php?t=799417

Attachment 1977635

I agree with most of what you say other than the fans should never be on without the motor running. Just about all late model vehicles with electric fans run with the engine shut off until cooled down below a certain temp.
I have my 71 C 10 with 6.0 running relays with my own setup because I don't like the fact that the fans run all the time if the AC is on. I fixed this and it has worked great now for over 4 years. Cost me less than $20.00. My 71 runs 185* no matter what the outside temp is.

[Putzer]

Originally Posted by Andy4639

I hope it does but I don't see how by the wiring schematic. Good luck with it.

I installed the diode; both ways. No luck fixing the issue either way.

Originally Posted by HO455

I am guessing that the yellow wire is expecting to see 12+ DC or an open line coming from the A/C clutch for a factory A/C installation. When hooked up to the LSX PCM it is likely that the fan #1 trigger connection is grounded until the fan is triggered. (Something commonly done to reduce EMF and electrical noise problems) This grounding is being forwarded by the Entropy fan controller and the result is the #1 fan runs continuously. This is why installation of a diode solves the problem.
It does appear that there is a problem with their diagram. On the fan wiring harness the color coding makes sense but the labels on the fan controller drawing seem to me to be wrong. Fan 1 in and fan 2 out labels appear to be swapped. I recommend checking with Entropy to be sure. Although in may not be an issue as the wiring appears (from the quick search of the interweb I did) to be in a metripak plug and if the harness is labled correctly you would have it wired correctly. It is likely most folks would never notice it.

Seems that there have been several iterations of their diagrams which leads me to believe they have had issues in the past. Im thinking I will get rid of the controller. I have 2 systems (pcm & entropy controller) that are attempting to turn the fans on at most likely different temps and theyre not going to communicate correctly.

Originally Posted by MDPotter

If I were you, I would throw out that fan controller and use a fuse block setup. A few observations:
-Fans should not be on with just the key on (engine off)
-Vintage Air should be able to override fan functions
-PCM supplies ground triggers. These grounds don't go to the grounds of the fans, but through the relays.

Attached is the GM dual fan wiring schematic with the Vintage Air trinary switch incorporated. More info on this here: http://67-72chevytrucks.com/vboard/s...d.php?t=799417

Attachment 1977635

thanks, I think I will get rid of the controller.

Originally Posted by Andy4639

I agree with most of what you say other than the fans should never be on without the motor running. Just about all late model vehicles with electric fans run with the engine shut off until cooled down below a certain temp.
I have my 71 C 10 with 6.0 running relays with my own setup because I don't like the fact that the fans run all the time if the AC is on. I fixed this and it has worked great now for over 4 years. Cost me less than $20.00. My 71 runs 185* no matter what the outside temp is.

Can you PM me or post some pictures/diagram of how you wired this?

[Andy4639]

Here is my link to what I do. This shows the Impala but it works the same way.

http://67-72chevytrucks.com/vboard/s...d.php?t=738555