2000 RT 10 Cooling Fan Module or Cooling Fan Issue

[Citrus080]

Hello,

Our Dodge Viper was leaking antifreeze. Took it to the Dodge dealership.Dodge said it was the radiator. Turns out we did not have the factory radiator. We had a fluidyne aftermarket radiator. So we ordered a roe racing aluminum radiator. And Dodge put it in. 15 minutes after getting the Viper back. The temperature gauge when sitting still would climb over 225 degrees. It will not go back down to 180 degrees unless we were driving over 20 miles an hour or on the freeway. Then the check engine light came on.

Took it back to the Dodge dealership the same day. They said the check engine light code was. "Cooling fan module" . Dodge said they can fix it. However, they did not make that part anymore. And we would have to track down the cooling fan module and bring the car back and they could put it in.

Got the Viper back home and open the hood and noticed that the cooling fan was not running while the engine was on with the temperature steadily climbing. Per the manual, the cooling fan module is located in the cooling fan motor. Located a cooling fan motor from a salvage yard. Bought it. Decided to install it ourself since it seemed like an easy job. But when I looked at the cooling fan motor that was on there, one of the wires was melted and frayed. When I took that cooling fan motor out and plugged in the used salvage motor and put everything back together. Cooling fan motor did not run and check engine light is still on.

The check engine light has never came on before. Car has never ran hot before. Even sitting in rush hour traffic on hot summer day.

Any ideas or help. I've included pictures or the bad cooling fan motor.

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[dave6666]

Sharf sells an OEM style replacement motor for the OEM fan assembly. I bought one to see what they look like and it fit perfectly on a spare fan I have laying around.

You should also look inside the chassis side harness connector for melting as well as pull the 2 fan relays and look for melting in the PDC as well as the relay bases themselves. There are plenty of improvements that can be made to the Gen 2 fan electrical system. I run all 3 of my fans straight from the battery, switched by the PCM/PDC, with SSRs. That system has been bulletproof in the Texas heat for 5 years now.

BTW, I tried a Roe radiator as well. Maybe your luck will be better than mine. It lasted less than 6 months. Their warranty repair lasted less than 1 month. This is on a car that gets driven mind you. Not a trailered show queen that never even gets hot.

[Citrus080]

Sharf sells an OEM style replacement motor for the OEM fan assembly. I bought one to see what they look like and it fit perfectly on a spare fan I have laying around.

You should also look inside the chassis side harness connector for melting as well as pull the 2 fan relays and look for melting in the PDC as well as the relay bases themselves. There are plenty of improvements that can be made to the Gen 2 fan electrical system. I run all 3 of my fans straight from the battery, switched by the PCM/PDC, with SSRs. That system has been bulletproof in the Texas heat for 5 years now.

BTW, I tried a Roe radiator as well. Maybe your luck will be better than mine. It lasted less than 6 months. Their warranty repair lasted less than 1 month. This is on a car that gets driven mind you. Not a trailered show queen that never even gets hot.

Hello,

Thanks so much for the reply. This kept me up all night thinking what it could be. I checked inside the chassis side harness and no melting. But when I checked the 2 fan relays.. One was melted. Pulled the melted relay off and the harness that the melted relay pluged into was melted.

I've included pictures.

What system did you go with that has lasted these 5 years to keep your fans running and temp down.

Also the Viper is leaking antifreeze again after I let the Viper run to see if the fan would cut on. Gonna get it up on a jack stands and look under it soon. I think it might be the hoses as I believe they are the original hoses.. But I'm gonna get this fan working first.. Thanks for the help20200216_090230.jpg
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[Fatboy 18]

That relay should clean up just fine with a little emery paper

Mmmm, thats FUBAR!

Check out these old threads

https://driveviper.com/forums/thread...oming-On-96-RT

[dave6666]

I designed my own system. It tucks in under the air box. The SSRs are on the bottom side and are not visible. The circuit breaker and supply cable from the battery are on top however. A vast improvement over the PDC located cube relays, and even the cube relay relocation projects that don't address the root cause of the cube relay failure.

A word about hoses and clamps. And check to see if the shop that did the work on your car removed the superior OEM design constant tension hose clamps and replaced them with inferior worm drive clamps. As hoses age they get softer and loose their resilience to compression at the clamp. The factory constant tension clamps are designed to self tighten as the hoses age. When the factory clamps will no longer seal the hose it's likely not the fault of the clamp. The hoses are aged. Many people, including shop mechanics, love to think that anything the engineers that design cars use from the factory instantly qualifies to be replaced with aftermarket so you can say you've upgraded. Putting worm drive clamps on factory rubber hoses is instead a downgrade.

Most of the factory hoses are still available but can take a while to source. Many people use the aftermarket silicone hoses which yes, require worm drive clamps as the silicone is too hard of durometer to seal with OEM style constant tension clamps. And, guess what, the worm drive clamps will require retightening after a few months as the silicone takes a slight set.

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[MH60M]

Search for "MotoIQ". They did a pretty good write up on this. It's similar to Dave's setup.

It actually a pretty common Viper issue. Don Scharf Auto and Jones Auto should have used fuse boxes foe sale.

[dave6666]

I've never paid attention to those write ups because I design all my own stuff, but I do recall it being mentioned that write up simply relocates the factory relays outside the PDC. Which as mentioned by me, the factory style relays are one of the root causes of the problem. So if that is the case, there is very little similar about mine versus theirs.

[ellowviper]

Personally, I check mine periodically. One would think it would be easy to just use the existing high/low fan power wires as a low amp 12v trigger for a separate hi amp relay to provide power to the fans. Maybe someday I'll do that....before any melting wires force me to....

[Dan Cragin]

Ive seen the whole fan wiring harness and the fuse box melt numerous times. The fan starts drawing too much current.
Ive had to rewire numerous cars, change the fan and add a fan controller.

Make sure your fan is not rubbing on that aftermarket radiator, that will cause the fan to burn up like that.

[Nofire]

I've never paid attention to those write ups because I design all my own stuff, but I do recall it being mentioned that write up simply relocates the factory relays outside the PDC. Which as mentioned by me, the factory style relays are one of the root causes of the problem. So if that is the case, there is very little similar about mine versus theirs.

Any chance you have a write up or maybe even have a kit to sell for the whole fan relay system you have? I've been looking at something similar for my car and would love a bulletproof system like you're describing.

[Dan Cragin]

SPAL sells a relay kit for their fans which works well. You can use two of these to control the high and low speed fans. They are rated at 60 amps. You can hook these up to the factory computer fan control or use temp switches
to turn the fans on earlier if you desire.