Electric fans worth it?

[L31MaxExpress]

I think I found the unicorn P59 that controls an EV Clutch. Now to find an engine wiring diagram for a 2003 Trailblazer EXT 5.3L. Parts list looks like shares a P59 and EV Clutch.

EDIT- Pulled a stock tune off HP Tuners Tune Repository and it is a P59 with EV Clutch control.

 

[L31MaxExpress]

Found the pinouts for a P59 with an EV clutch. C1-42 is the PWM output for the Trailblazer specific fan relay. C2-30 is the input for the fan rpm signal from the clutch. Then I only have to add 5 volt reference and ground reference. I may mess with this soon and see if I can make the P59 operate the clutch in the same manner as it does on a 2003 Trailblazer. It will be nice to have the clutch vary the fan RPM in response to cooling demand and engine rpm.

 

[GMCTRUCKS]

Guys on eBay I bought a 3 core all aluminum radiator and tanks from radiators4less for or at least around ten years ago for a little over $225.00 and I’m truck has never overheated example I was stuck in traffic on I-10 for a long time the temp went up to 220 but no higher.

 

[kylenautique]

I like electric fans. Its an easy upgrade, and if you have a heavy duty clutch fan, when you will notice the difference is when its 90+ deg outside. You don't get the drag from the clutch fan especially if you have the heavy duty clutch. I also feel it keeps my A/C cooler when idling in traffic or slow around town speeds. Its a very easy install to do. I installed an LS alternator off a 99-2007 Silverado, but your stock alternator is more than fine. It bolts right up, charges better and you use the larger size stock belt for your truck. I only replaced the alternator because mine decided to take a dump on the way home from work. I used a fan off a 2004-2007 Suburban/Tahoe/Silverado Classic. With very little modifications it bolts right up and looks factory.

The next hurdle is wiring. Your 97 Silverado can control the fans via your ECM. You will need programming though. Once you get that dialed, I recommend using heavy duty relays and 12 or 10AWG wiring (I use 10) with a maxi fuse. The maxi fuse is important because they handle power surges better than ATO fuses. Is this overkill...maybe. Do I care? No. Does it work? Absolutely. I use Hella waterproof heavy duty relays too. I think electric fans get a bad rap sometimes because people skimp on this part. Small gauge wire, cheap relays, ATO fuses can cause failure. Call me captain overkill, but I have zero issues with my fans.

The final step... Air Conditioning control... There are a few different ways to tackle this. I used a trinary switch to control the AC pressure fan control. The other way is to use a 3rd relay off the A/C compressor, but the downside of that is its a huge power surge on your engine. The fans will kick on every time the A/C compressor kicks on. Big instant draw. I'm not a fan of this setup. Here is my post on how I install a trinary switch. https://www.gmt400.com/threads/the-best-electric-fan-install-with-a-trinary-switch.54076/

Everyone is going to have an opinion on E-Fans. Some love them, some hate them. I think my truck has more get up and go, runs cooler, and just performs better.

 

[Supercharged111]

I think I found the unicorn P59 that controls an EV Clutch. Now to find an engine wiring diagram for a 2003 Trailblazer EXT 5.3L. Parts list looks like shares a P59 and EV Clutch.

EDIT- Pulled a stock tune off HP Tuners Tune Repository and it is a P59 with EV Clutch control.

Well this claims to fit a 5.3L 2003 Trailblazer.

TrailBlazer EXT 5.3 2003 Engine Computer PCM ECM 12576106 Programmed to your VIN | eBay

GM installed this 12576106 PCM in all of the above applications. This was possible because each of these models received their specific programming from the factory. In other words, you can't simply swap a used PCM from one vehicle to the next.

www.ebay.com

Not sure if that PN is for a Gen 3 or 4 though. The early 5.3 TB may be your Huckleberry.

 

[L31MaxExpress]

Well this claims to fit a 5.3L 2003 Trailblazer.

TrailBlazer EXT 5.3 2003 Engine Computer PCM ECM 12576106 Programmed to your VIN | eBay

GM installed this 12576106 PCM in all of the above applications. This was possible because each of these models received their specific programming from the factory. In other words, you can't simply swap a used PCM from one vehicle to the next.

www.ebay.com

Not sure if that PN is for a Gen 3 or 4 though. The early 5.3 TB may be your Huckleberry.

It is my Huckleberry. I confirmed that a 2003 5.3 Trailblazer file is in fact a P59 calibration and that it uses the EV Clutch. I also found the wiring pinouts for it. PWM output is on the normal fan 1 output pin. The RPM input signal to the PCM goes to C2-30.

 

[Supercharged111]

It is my Huckleberry. I confirmed that a 2003 5.3 Trailblazer file is in fact a P59 calibration and that it uses the EV Clutch. I also found the wiring pinouts for it. PWM output is on the normal fan 1 output pin. The RPM input signal to the PCM goes to C2-30.

If that's the case, a 2002 might just be a P01. . .

 

[Dropped88]

Found the pinouts for a P59 with an EV clutch. C1-42 is the PWM output for the Trailblazer specific fan relay. C2-30 is the input for the fan rpm signal from the clutch. Then I only have to add 5 volt reference and ground reference. I may mess with this soon and see if I can make the P59 operate the clutch in the same manner as it does on a 2003 Trailblazer. It will be nice to have the clutch vary the fan RPM in response to cooling demand and engine rpm.

It should if you have a ac pressure like the 3 wire from the Camaro or 03 + trucks.

That's how I did my 2 fan setup with my p01 pcm. And that's the same way I'm gonna set up my 4200 that way but I'm using the trailblazer pcm in that swap

 

[L31MaxExpress]

If that's the case, a 2002 might just be a P01. . .

No 5.3L option in 2002. LM4 started in 2003 in those.

 

[L31MaxExpress]

It should if you have a ac pressure like the 3 wire from the Camaro or 03 + trucks.

That's how I did my 2 fan setup with my p01 pcm. And that's the same way I'm gonna set up my 4200 that way but I'm using the trailblazer pcm in that swap

I looked at the OE 2003 5.3 trailblazer fan settings. All the normal fan settings are set like a mechanical fan truck. Looks like the EV fan clutch uses engine temp and perhaps only ac status for control. I do not see any reference to ac pressure for fan control.