Project Viper GTS: Part 5 – Radiator Fan & Wiring Upgrade

Fan CompleteWith the fan complete, it’s ready to be installed.  All of our hard work looks fairly OEM and we are pleased with the result.

Fan Comparison Correct

The new 1998-2002 fan (above) is visually larger in diameter and covers more of the radiator fan face than our original 1996-1997 fan (below).  With our electronics mounted; this is now an easy plug and play install with only the need to connect our wire to a dedicated power and ground source.

Category1996-1997 Fan1998-2002 FanDifference
Fan Diameter15.5″17.5″2″
Fan Sq. In188.69 sq. in240.53 sq. in51.84 sq. in (27.5% larger)
Flap Sq. In67.08 sq. in60.32 sq. in6.76 sq. in (10% smaller)
Total Moving Sq. In255.77 sq. in300.85 sq. in45.08 sq. in (17.6% larger)

The new fan is 27.5% larger which will greatly improve the cooling ability in traffic while the flaps are actually 10% smaller in area, but thanks to a larger fan, the total exit area is 17.6% larger which will also improve the cooling at highway speeds and on track. The new fan is a win-win.

Fan Height

The new fan (left) is also much lower in profile than the original (right).

Fan Mounted

Having removed the center two mounting studs, the new fan slides in and bolts up with ease.

Plugged in

The chassis side connecter plugs right in to the new fan’s plug, which we are using as the trigger for our standalone relays.  If we weren’t aware of the fan relay box issue, or didn’t think it was a problem, the install would be complete and this article would barely be two pages long.

With the fan mounted and ready to go, the last thing to do is to run a dedicated power and ground wire to the fan.


  1. Radiator fan wiring upgrade they auxiliary relays what wires output to the fan either number or color it’s not clear thank you for your help

  2. Have a customer with a 96 wanting to do this upgrade to his cooling system, any idea where the cooling fan may be available?

  3. That’s weird. I’ve always been taught to crimp ring terminals on the cut side, so it forms a B-type crimp that secures the wire. Well, whatever works!

  4. good evening i have a 1999 viper GTS and i just got the radietor from you do u by any chance sale the hole kit for the fan to make it work better please let me know so i can buy ti thanks

    1. What temp does the fan kick on? Did you change the low or high speed fan temp threshold by flashing your ECU? If you’re tripping the 60A circuit breaker, then you need to troubleshoot and find what is causing the excessive amp draw.

  5. Is the Bosch relay with the 332 209 151 number the same relay? Stats look similar to the one you have installed

    1. Those appear to be 30A relays vs the 50A relay that I used. I would recommend using the part number for the 50A relay.

  6. can u send me more detail about the wires evething look nice but i can not see every cable where they go to make shure i conected right i need the order or a better pictures can u send me a diagram i got all the parts thanks

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