98 silverado electric fan upgrade - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Greasey Harley · 04-29-2021, 01:44 AM

99 Silverado with a clutch fan.
We found a newer suburban parts truck with dual electric fans.
do I just need an aftermarket wiring harness to make this work?

The harnesses I have found say it plugs into the PCM. Will the PCM recognize this on a truck that never had electric fans?
FWIW, I'm a carburetor guy, this is for a buddy's truck. I have no idea how to wire components into a confuser controlled vehicle. I could wire it completely separate from the PCM, but I ain't sure the truck would like that.

Usually in the old truck section
-Russ

EVRLET · 04-29-2021, 12:34 PM

You have two options for wiring.

Install to where it comes on with temp switch, no pcm control.

Or install with pcm control but you’ll need to get into the pcm with HP Tuners or some other software to set up e-fans. Then the computer will control the fan. The PCM has to be an LS based pcm.

If you have the 411 pcm already controlling your L31 engine, then you can use HP Tuners on that.

I just installed e-fans in a 2003 Denali and went into the PCM to set it up. If you found the e-fans on a factory suburban, grab the relay box and all the wiring for it. The relay box is attached to the main under hood fuse box. With this, you don’t need any aftermarket wiring kit. But you will need to have it pcm controlled.

The factory relay box looks like this:

Greasey Harley · 04-29-2021, 07:53 PM

Excellent, thank you.
Is the harness off the suburban a stand alone harness, or will it have to be separated out of the main harness?
Don't mind spending 50 or 60 bucks on a harness, if it's going to be a cleaner/easier install.

EVRLET · 04-29-2021, 10:41 PM

Yes it’s a stand alone.

Tom · 04-30-2021, 12:27 PM

Blackbear can turn Efans on in 1998 model ECU's, you don't need an 0411 computer swap. Doesn't work on 97 and lower although I don't remember what they said was the reason.

EVRLET · 04-30-2021, 06:37 PM

I’m curious now. What 1998 truck had factory efans that the PCM would have this tab available for turn on? Is this an LS based PCM from a Camaro or Corvette that had an LS1?

Just call me Sean · 05-01-2021, 12:41 AM

Black plug pin 9 dark blue wire is labeled auxiliary electric cooling fan for 98-99. I rewired my 99 to take a 96 computer.

EVRLET · 05-01-2021, 12:11 PM

Groovy. Learn something new

04-29-2021, 01:44 AM	#1
Greasey Harley Registered User Join Date: May 2013 Location: Post Falls, ID Posts: 884	98 silverado electric fan upgrade 99 Silverado with a clutch fan. We found a newer suburban parts truck with dual electric fans. do I just need an aftermarket wiring harness to make this work? The harnesses I have found say it plugs into the PCM. Will the PCM recognize this on a truck that never had electric fans? FWIW, I'm a carburetor guy, this is for a buddy's truck. I have no idea how to wire components into a confuser controlled vehicle. I could wire it completely separate from the PCM, but I ain't sure the truck would like that. Usually in the old truck section -Russ __________________ Insert clever text here:

04-29-2021, 12:34 PM	#2
EVRLET Registered User Join Date: Aug 2015 Location: Las Vegas NV Posts: 354	Re: 98 silverado electric fan upgrade You have two options for wiring. Install to where it comes on with temp switch, no pcm control. Or install with pcm control but you’ll need to get into the pcm with HP Tuners or some other software to set up e-fans. Then the computer will control the fan. The PCM has to be an LS based pcm. If you have the 411 pcm already controlling your L31 engine, then you can use HP Tuners on that. I just installed e-fans in a 2003 Denali and went into the PCM to set it up. If you found the e-fans on a factory suburban, grab the relay box and all the wiring for it. The relay box is attached to the main under hood fuse box. With this, you don’t need any aftermarket wiring kit. But you will need to have it pcm controlled. The factory relay box looks like this: Attached Images __________________ Customization is what you want it to look like -- not what other people think it should look like Last edited by EVRLET; 04-29-2021 at 12:40 PM.

04-29-2021, 07:53 PM	#3
Greasey Harley Registered User Join Date: May 2013 Location: Post Falls, ID Posts: 884	Re: 98 silverado electric fan upgrade Excellent, thank you. Is the harness off the suburban a stand alone harness, or will it have to be separated out of the main harness? Don't mind spending 50 or 60 bucks on a harness, if it's going to be a cleaner/easier install. __________________ Insert clever text here:

04-29-2021, 10:41 PM	#4
EVRLET Registered User Join Date: Aug 2015 Location: Las Vegas NV Posts: 354	Re: 98 silverado electric fan upgrade Yes it’s a stand alone. __________________ Customization is what you want it to look like -- not what other people think it should look like

04-30-2021, 12:27 PM	#5
Tom driving is in my blood Join Date: Dec 1999 Location: Mesa AZ Posts: 5,690	Re: 98 silverado electric fan upgrade Blackbear can turn Efans on in 1998 model ECU's, you don't need an 0411 computer swap. Doesn't work on 97 and lower although I don't remember what they said was the reason. __________________ -78 c10 short/step: 388cid, M20, 5/5 drop, lots more. Playtoy and first vehicle. -98 c1500 x-cab: 5.7L, 17" rims, 5/6 drop, flowmaster, helper bags,NBS rear disk brakes. -02 Suburban 4x4: leveled front -CBR600F4i, CBR600RR, CBR1000RR, and standup skis DISCLAIMER: I cant spell for the life of me.

04-30-2021, 06:37 PM	#6
EVRLET Registered User Join Date: Aug 2015 Location: Las Vegas NV Posts: 354	Re: 98 silverado electric fan upgrade I’m curious now. What 1998 truck had factory efans that the PCM would have this tab available for turn on? Is this an LS based PCM from a Camaro or Corvette that had an LS1? __________________ Customization is what you want it to look like -- not what other people think it should look like

05-01-2021, 12:11 PM	#8
EVRLET Registered User Join Date: Aug 2015 Location: Las Vegas NV Posts: 354	Re: 98 silverado electric fan upgrade Groovy. Learn something new __________________ Customization is what you want it to look like -- not what other people think it should look like



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