Purpose:
The radiator fan kit serves two functions. It acts as a way to make your fan come on earlier than the stock setting and acts to cool the engine after the key has been turned off.
When you shut your viper’s engine off, the radiator fan stops running, no matter how hot the engine may be. Our kit combats overheating and heat soak by cycling the radiator fan on as needed. The fan ‘on time’ will be a direct result of the temperature the engine was at when turned off. The hotter the engine is, the longer the fan kit will run to cool it. A natural flow is created when the cooler water in the radiator sinks and is replaced by hot water through the upper radiator hose. Helps protect your investment by having a cooler running engine in traffic or after a run on the track!
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SKU: RR-RFCG2
Tools required:
- 15mm wrench or socket
- 13 mm wrench or socket
- 8 mm or 5/16” wrench or socket
- Pliers
- Straight slot screwdriver
Installation steps:
1. Leaning over the driver side front wheel, take the relay end of the supplied wiring harness and carefully run it along the larger factory wiring harness back toward the windshield under the brake lines and all the way to the forward side of the PCM (Powertrain Control Module) cover that is near the washer fluid reservoir. Place the box with adjuster screw directly behind the drivers’ headlight.
2. Remove the forward top bolt on the PCM cover, just below the fuse box. Install the relay on this bolt. Do not over tighten. [Figure 1]
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Figure 1
3. Remove the 40-amp fuse from the fuse holder during installation. Connect the wire with in-line fuse holder and eyelet to the power supply post at the top of the power distribution center using the 15mm wrench or socket. [Figure 2]
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Figure 2
4. Route the ground wire with eyelet to the grounding post that is located directly behind the drivers’ front wheel, at the top of the frame and below the washer reservoir. Using the 13mm wrench or socket, attach the ground wire to the grounding post. [Figure 1]
5. Leaning over the driver side wheel, open the ¾” factory wire harness loom mounted on the engine side of the driver side fender well across from the power steering reservoir. Locate the 12 gauge dark green wire in the loom. Using the green wire from the fan kit as a guide, note the location that the quick tap should be installed on the dark green wire. Install the yellow quick tap connector to the dark green wire by folding the connector over the wire and clamping it shut with the pliers. Plug the fan kit green wire male terminal end into the yellow quick tap connector. [Figure 3]
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Figure 3
6. Run the fan switch temperature probe forward, under the upper radiator hose and toward the top corner of the radiator, between the hose and air filter housing.
[Figure 4]
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Figure 4
7. At the top corner on the driver side of the radiator, there’s a small gap between the radiator fan housing and side tank of the radiator, where you can see the fins of the radiator (with adequate lighting). This is where the temperature probe will be installed. Insert the temperature probe between the fins and push it all the way forward until the probe stops (a pair of needle nose pliers, gently gripping the probe, not the tube connected to it, is helpful during installation). Approximately ½” of the probe will stick out from the back of the radiator after you install it.
[Figure 5] If the gap here is too small, loosen the fan to install.
[I didn’t have access to the radiator fins through the gap, so I had to remove the radiator fan shroud to insert the temperature probe into the radiator fins, Figure 6].
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Figure 5
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Figure 6
8. The temperature control box will be mounted to the back side of the headlight housing. Clean the area thoroughly and use the supplied Dual Lock to secure the box. We suggest mounting the adjustment knob for ease of adjustment. [Figure 3]
9. Turn the post on the control box fully clockwise (it may already be set at full clockwise).
10. Install the 40-amp fuse into the fuse holder. Note: If you ever want your fan to be disabled you can remove this fuse.
11. Test your installation by turning the post on the control box counter clockwise. Without the engine running, the fan should turn on before you reach the full counter clockwise position. If the fan activates, you’ve installed everything correctly and you can turn it back to full clockwise.
12. With the temperature probe securely inserted into the radiator, use a single tie wrap to hold the tube from it to the upper radiator hose, near the probe (to keep it from sliding out). [Figure 4] Check all connections and use the supplied tie wraps to secure the new harness to the existing harness.
13. Now it’s time to set the desired fan activation temperature. Start your viper and allow it to idle with the A/C off in a well ventilated area until it reaches full temperature (needle into the 190 range). When the needle gets midway between the second and third line in the 190 range [Figure 7] slowly turn the adjuster counter clockwise until you see/hear the fan come on (or feel the air movement). Your goal is to have the fan come on when the needle gets to the third line over 190. If you turn the adjuster too quickly you may pass the desired temperature turn on point (setting it too cold). If this happens, reset the temperature adjuster by turning it clockwise until the fan shuts off and adjust again.
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Figure 7
14. After the desired turn on/off fan temperature is achieved, operate the viper as usual.
We recommend 70% distilled water, 30% antifreeze and 1 bottle of Red Line brand Water Wetter as a coolant fluid mix which will produce good heat transfer characteristics.
Note: We suggest the turn on temperature be set when the temperature gauge needle matches the supplied diagram. This temperature setting should allow for lower cruising temperatures and fan cycling during normal driving, and reduced temperatures during spirited driving conditions without excessive fan run time when the viper is shut off. Use caution when setting the fan turn on temperature. If it is set too low, the fan will continue running long after you have shut the engine off which may result in a dead battery.
