04 truck Efan problem using pins 33 and 42

[BlackGMC]

Well I finished my efan install today, however the computer is not turning them off and on correctly. I can use the Bi-directional controls to turn them off and on, both High and low speeds but using the modified 05 PCM setting/parameters does not seem to work. The fans just stay on High all the time.... Any advice would be great. Attached is a copy of my tune.

[BlackGMC]

I figured out the problem. I had the display settings on EFI live setup as kPa instead of PSI, and I was inputing PSI values, so the reason they were always on is because my AC enable setting were set to something like 30 psi. So I changed the display units in EFI Live to PSI and kept my same settings and everything works perfectly. The fans don't come on until they are supposed to!!!! So now the AC pressure is in control and the temp is also in control. Oh and my AC is really cold and it is ~97* outside right now.

Here are my settings.
http://i27.photobucket.com/albums/c185/BlackGMC/Truck/EfanSettings.jpg

[kbbrett]

Ok, I have a couple questions regarding this. I am finishing up a 5.3 conversion in a Jeep wrangler. At the last minute we decided to run an electric fan. I programmed the junk yard PCM with the operating system from my wifes 02 Suburban and would like to use the PCM for fan control. I have been looking tonight for the proper pins, but my brain is fried. Does anyone want to share with me wich pins I need ? . I have to finish this thing tomorrow so I can go on a desperatly needed vacation. Thanks. Brett .

[Shupe]

I have been looking tonight for the proper pins, but my brain is fried. Does anyone want to share with me wich pins I need ? .


Not sure but BlackGMC posted the problem using pins 33 and 42 in the subject line. I'd suspect these are the two your looking for if running the same pcm.

[Chevy366]

I figured out the problem. I had the display settings on EFI live setup as kPa instead of PSI, and I was inputing PSI values, so the reason they were always on is because my AC enable setting were set to something like 30 psi. So I changed the display units in EFI Live to PSI and kept my same settings and everything works perfectly. The fans don't come on until they are supposed to!!!! So now the AC pressure is in control and the temp is also in control. Oh and my AC is really cold and it is ~97* outside right now.

Here are my settings.
http://i27.photobucket.com/albums/c185/BlackGMC/Truck/EfanSettings.jpg
Yeah , cool deal isn't it ? A/C does seem to cool down quicker .
I did the 05 fans on mine as well , love them , used factory harness off 1/2 ton pickup .
Yeah , pin 42 and 33 are the right ones , one is on the blue the other the green connector .

[BlackGMC]

I used pin 33 and 42, but if your referring to pins and the actually Hardware you plug into the harness itself, I got those from a member on PerformanceTrucks.net

[kbbrett]

No, I just need to know which pins. I am using a 12200411 PCM, not sure if it uses the same pins or not. I will find out shortly.

[BlackGMC]

I am pretty sure on a 02 the pin 42 is good, but not he pin 33 on a 02 PCM. I will try and find a pin out diagram so you know which one to use instead of pin 33.

[kbbrett]

Actually, if pin 33 is good, that should be all I need. Thanks.

[Chevy366]

http://www.ls2.com/forums/showthread.php?postid=22#post22

[BlackGMC]

Actually, if pin 33 is good, that should be all I need. Thanks.

That is what I am trying to tell you Pin 33 on 99-02 is not the same asn 03+. I believe it is used for something completely different. At least this is what I have been told.

[kbbrett]

It looks to me like C1 42 is not used on an '02 truck. C2 33 is blend door.

[ChipsByAl]

Kbbrett you are correct. The Blue connector C1 terminal 42 is not used on the 2002 truck. On the Red connector C2 terminal 33, that circuit is used to control the recirculation door for the A/C. If you have the automatic climate control, this circuit is not used directly by the PCM. For vehicles with manual A/C controls the PCM will force recirculation mode if the high pressure gets out of range. The user control of the recirculation door will still be functional. In either case the switch at "G0106" needs to be changed to fan #2 control to allow PCM control of both fans.
The primary fan control is at C1-42 and secondary fan control is at C2-33. If using only one fan, use the primary circuit.
Al

[Chevy366]

Part of the problem people will buy a Nelson Harness which is not made for the 05 34" fans (LS1 27") and try to use it , he needs to add a another trigger wire and re-configure the relays .
And another bad thing is most people will do a harness for the larger fans (05 34") and not add any protection (fuses 40 amp min) , oh well .

http://i71.photobucket.com/albums/i138/My-fotos/dscn2341.jpg

http://i71.photobucket.com/albums/i138/My-fotos/dscn2338.jpg
Bottom view


Factory harness and will work for most trucks .
Went up a few dollars now close to 2 , part #15216042 .
See the fuses and large relays , what you need for the larger fans .

[ChipsByAl]

I would recommend the three relay setup if you are planning on using dual fans. For low speed, both fans run at low speed in series. On high speed, both fans run with full voltage in parallel.
AL

[Chevy366]

Factory Diagram :
Yours is close .

[99Silver6.0]

I built my own harness. Made an EXACT copy of the GM harness. Im not paying $200+ for a harness I need that comes with a harness I dont. Im into my harness a whole $40 bucks and some time. And it works the same way as the GM unit.

[Chevy366]

I built my own harness. Made an EXACT copy of the GM harness. Im not paying $200+ for a harness I need that comes with a harness I dont. Im into my harness a whole $40 bucks and some time. And it works the same way as the GM unit.
$40.00 not bad , I got the factory harness when they were 108 to the door .
They must have caught on to what people were doing and raised the price .

Can you give a link to the relays and fuses you used ?

[99Silver6.0]

Id link ya to the relays but I got them local. I didnt skimp it ont he relays. I got 3 70amp Cole Hersee SPDT relays at $8 a pop.

Sockets same deal, got them local. They look kinda like these though. http://www.partsexpress.com/pe/showdetl.cfm?&Partnumber=330-075

Fuse block isnt sealed but I chose it for the heavy wiring it had. Has HUGE power wires on it. $15
http://partimages2.genpt.com/partimages/218080.jpg

But all in all worked well. I hid all of it right under the main fuse panel. Had to remove the big plastic cover that snaps off. Ill get some pics tomorrow.

On a side note, you will need 2 PCM pins!!

[Chevy366]

Id link ya to the relays but I got them local. I didnt skimp it ont he relays. I got 3 70amp Cole Hersee SPDT relays at $8 a pop.

Sockets same deal, got them local. They look kinda like these though. http://www.partsexpress.com/pe/showdetl.cfm?&Partnumber=330-075

Fuse block isnt sealed but I chose it for the heavy wiring it had. Has HUGE power wires on it. $15
http://partimages2.genpt.com/partimages/218080.jpg

But all in all worked well. I hid all of it right under the main fuse panel. Had to remove the big plastic cover that snaps off. Ill get some pics tomorrow.

On a side note, you will need 2 PCM pins!!
Wow 70 amp Single Pole Double Throw (SPDT) relays , should last .
The fuse block , where did you get that at ?
Pics would be nice .
When I made one I used these : http://www.alliedelec.com/Search/ProductDetail.asp?SKU=587-1001&SEARCH=&MPN=BR05%2DFW&DESC=BR05%2DFW&R=587%2D1001&sid=46CCCE003BA7E17F
They worked real nice because you can link them together .
PCM pins , someone else has posted this link but here it is again http://www.eficonnection.com/eficonnection/100w.aspx

Thanks for the info .

[BlackGMC]

I ended up making my own fan shroud, bought some summit efans and made my own harness. I bought my sockets and relays from partsexpress. The summit fans don't pull that many amps, so I am only running 30 amp fuses and relays. The only problem was trying to roll beads into 18 gauge sheet metal by myself, they are not as straight as I would like, but oh well.
I did this all for ~$180.

http://i27.photobucket.com/albums/c185/BlackGMC/Truck/Efan01.jpg
http://i27.photobucket.com/albums/c185/BlackGMC/Truck/Efan02.jpg
http://i27.photobucket.com/albums/c185/BlackGMC/Truck/Efan04.jpg
http://i27.photobucket.com/albums/c185/BlackGMC/Truck/Efan05.jpg

[Chevy366]

Very nice job BlackGMC .
And it looks as if you did your own CAI tube as well .

[BlackGMC]

Very nice job BlackGMC .
And it looks as if you did your own CAI tube as well .

Thanks and yes I made the lid out of fiberglass and the tube out of steel, wrapped in header wrap then fiberglassed over that too.

http://i27.photobucket.com/albums/c185/BlackGMC/lid1.jpg
http://i27.photobucket.com/albums/c185/BlackGMC/IntakeTube1.jpg
http://i27.photobucket.com/albums/c185/BlackGMC/tube2.jpg
http://i27.photobucket.com/albums/c185/BlackGMC/Final2.jpg

[Chevy366]

Man , very inventive , and talented . :cheers:

[BlackGMC]

Man , very inventive , and talented . :cheers:

Thanks, :cheers:

[BlackGMC]

BlackGMC: Very slick fabrication work. I'm planning doing something similar for my 4.3L S-10. I'm guessing you have a Flex-A-Lite 114 and 116 there?

Have you noticed any difference in speed between the two when running in series? I've read posts that some ppl have tried the series / parallel and claim that both fans don't necessarily start and / or run at the same time / speed.

Also, did the little plastic screw bosses come with your fans or did you have to order them?

The fans I purchased were summit brand fans 12" and 14", they were the cheapest and lowest amp draw.

I am not sure what your asking in regards too

"Have you noticed any difference in speed between the two when running in series? I've read posts that some ppl have tried the series / parallel and claim that both fans don't necessarily start and / or run at the same time / speed."

The plastic screw bosses can with the fans.

[joecar]

Nice work... :cheers:

[99Silver6.0]

http://i24.photobucket.com/albums/c26/jtskier11/DSC01495.jpg
http://i24.photobucket.com/albums/c26/jtskier11/DSC01494.jpg
http://i24.photobucket.com/albums/c26/jtskier11/DSC01491.jpg
Relays at right, fuse block at top left, power leads at center. Looks like a mess but its all the other OE wiring that makes it look crappy.
http://i24.photobucket.com/albums/c26/jtskier11/DSC01492.jpg
Wheres the wires now???????????? GONE!!

[Shupe]

BlackGMC - Nice work!

[BlackGMC]

I was just curious if they both seem to turn at approximately the same speed when on low. Of course that question makes the assumption that you have them wired in series for low speed.

They seem to run at the same speed on the low settting, and yes for the low speed trigger they are wired in series.