Can a weak battery cause the cooling fan to not operate?

AaronFL · May 26, 2013

My radiator fan has been working intermittently for a few weeks. I replaced the relays and checked the connectors and I thought I had fixed it. However today I went to the grocery store and my car would not turn over when I came out. I jump started it and it would not idle unless I had my foot on the throttle. I managed to get it back home and by the time I was close to my house the idle was fine but the cooling fan was not working and I was about to puke coolant. I have noticed the past couple of weeks that the starter was not turning over as easily as it used to and I only drive it a couple of times a week for short trips. I put a new battery in it in March. Could all this cooling fan hoop be related to the pcm being grumpy from low juice? Thanks for the help! I have been chasing this fan issue for a few weeks. I guess I better dig out the battery tender.

AaronFL · May 26, 2013

Just a quick update....I let her sit on the battery tender for a couple of hours and then took her out for a 50 mile cruise, trying to keep the RPMS between 2-3k. The radiator fan is running like a champ. I guess she will be kept sippin on the battery tender for the future.

Fatboy 18 · May 27, 2013

Good to hear, I did read your first post earlier, but did not know the answer

I have had trouble in the past with a fan relay on my 2000 GTS, I now carry a spare in the car (just in case). But being as you said you had already checked the relays I figured you had it covered.

Battery tender is a must have item on a Viper

AaronFL · May 27, 2013

Thanks for the reply! The issue is, I don't have a readily available AC outlet to plug my battery tender in where my car is. I ended up going out and buying a large deep cycle battery and inverter to keep her juiced up. I only had it on the tender for 2 hours yesterday via the built in inverter of a power jumper pack. When I drove to walmart today to get the battery, the fan worked fine...however, on the way to Harbor Freight the fan stopped working...but then it started to work again about 5 minutes later. So, I wonder if I am hovering around the voltage needed to run the fan +/- enough for it to work only intermittently. I have the car hooked up right now to my battery tender rig and I will let it run until fully charged and then report back. I hope I won't have to buy a new car battery.

Fatboy_18...on a side note, are you the gentleman in the videos I have seen on Youtube (FgearTV channel) de-catted in a revving match? If so...praise to you!

Fatboy 18 · May 27, 2013

He He, Yep that's me

AaronFL · May 27, 2013

Nice! I thought it was you! I bet you and your son have a blast with it!

Fatboy 18 · May 27, 2013

How to exit the car show
http://www.youtube.com/watch?v=EG4o97sQS1Y

@2.40

AaronFL · May 27, 2013

Nice! Now that is some torque! I also think that is the first time I have seen an F40 do a burnout, haha. Thanks for the link.

jdeft1 · May 27, 2013

Good show sir! I like.

Fatboy 18 · May 28, 2013

Thanks guys

AronFL, Sorry for the slight thread Hi jack, Please keep us posted if your problem persists, you really do not want to be putting very hot temperatures through the engine

AaronFL · Jun 1, 2013

Update:
I had the battery tender on the Viper for a couple of days and got the "green" light. The fan still seems to only work sometimes. I drove around and the temperature increased to 220...no fan. I parked it and came back 5 minutes later and started it up temp at 180 and the fan came on. I don't have the A/C on, but is it possible that low freon could cause the fan to not come on, even with the A/C off? I have been looking through my service manuals, but I can't find anything definitive.

My car does have the old style Roe fan timer installed. I removed the fuse from it to take it out of the mix, but that didn't seem to solve the problem.

I think I have to check a few more things, but my list of possible causes:
-loose wire somewhere
-possible damaged wire from the Roe fan control kit (I noticed this has those clip on wire tappers that seem to cut into the original wires...possibly damaging OEM wire?)
-faulty PCM
-something with the low/high pressure a/c switch or low freon
-failing fan motor

I have my multi-meter with me in the car. I need to probe the relay socket contacts in the PDC when the system is not working to see if power is being sent to the relay when it is supposed to. That will narrow down the problem.

xvenomx · Jun 1, 2019

I have had similar problems with my 2000 GTS. I have replaced the relay fuse multiple times. I took it in to the dealer to have them investigate the problem, and was told that the fan motor was the problem. Well know one on this planet seems to have a replacement motor. I was also told that if I do find one it will have to include the shroud. "NEWS FLASH!", I found a motor and was able to replace it without replacing the shroud. I tested it on the bench first, and I thought to test the old motor as well, and it worked fine as well. But when I connected it back up neither would. There appears to be a short in the relay box which I am not sure how to approach yet. So I did make a bypass for the fan system with an on and off switch!

Steve-Indy · Jun 1, 2019

Look at the back side of the relay socket...corrosion seems common there. Also, some have rewired the fan relay to the blank socket in that "box".

Look up a post by dave6666 where he describes in detail a fix for the aging relays.

Can a weak battery cause the cooling fan to not operate?

AaronFL

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AaronFL

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Fatboy 18

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AaronFL

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Fatboy 18

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jdeft1

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