Radiator cooling fans not working

KATHLEEN ADAMS

MEMBER
2003 BUICK RENDEZVOUS
3.0L
V6
2WD
AUTOMATIC
90,000 MILES

Mechanic turned sensors off on my car so the cooling fans would continuously run. I was in a wheelchair recovering from surgery for a broken leg and had to rely on someone else to drive me to appts and PT. It was her boy friend who took car to this particular shop. They had replaced the thermostat but fans wouldn’t kick in when they were supposed to, so mechanic talked to me and suggested he could turn sensors off to keep fans running. I just found out car won’t pass smog as long as “service engine soon” light is on which came on after sensors were turned off. I think vehicle check light has also come on a few times. I cannot take car back to same place and need to find someone who can turn them back on so I can get it smogged and overdue registration taken care of. I called a few places and they literally hung up on me when I asked if they could turn the sensors back on. A friend is checking it out for me now and said one of the fuses is missing and another one needs to be replaced. I can’t remember which one was missing off the top of my head right now but I am wondering if this can be turned back on manually so I can get it smogged and registration updated or if it has to be turned back on with the same computer app he used on his iPad? Can I reset and clear the “service engine soon” message to go ahead and smog it? I need to get transmission serviced, find oil leak and get a tune-up and check radiator. It is scary that the temperature gauge no longer worked once he turned sensors off and I would like to have it back on again now that I am able to drive again and maybe explore options about the cooling fans not coming on like they are supposed to. I see several others on here have had similar issues with theirs. If someone could please point me in the right direction, I would be so very thankful.

Wednesday, March 31st, 2021 AT 12:06 AM

3 Replies

ASEMASTER6371

MECHANIC
52,796 POSTS

Good morning,

First, you cannot turn off the sensors for the cooling fan. That is why you got the response you did from the shop you called. That is not possible.

It sounds like he jumped a relay to run the fans all the time for you. I attached a wiring diagram of the fans for you to view. Tests will need to be done to find the reason for them not coming on.

https://www.2carpros.com/articles/how-to-check-wiring

https://www.2carpros.com/articles/how-to-use-a-voltmeter

https://www.2carpros.com/articles/how-to-check-a-car-fuse

https://www.2carpros.com/articles/how-to-check-an-electrical-relay-and-wiring-control-circuit

I need the code that is set to prevent the emissions from passing. Can you post it here for me?

Roy

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Wednesday, March 31st, 2021 AT 7:53 AM

KATHLEEN ADAMS

MEMBER
18 POSTS

Thanks for replying Roy! OMG I did was so P.O'd about those two shops hanging up on me! They must have thought I was trying to prank them or something. I kind of wondered how this could be possible, since everything I've been looking up about the cooling system didn't mention anything like the guy had said, but I was trying to make sure I said it exactly the way the guy told me. The smog shop didn't test my car to get any codes because he didn't want me to waste my money knowing it wouldn't pass smog and told me to take it to a smog shop that also did repairs. I never trust taking my cars to shops mostly because I used to be married to a mechanic who taught me a lot and he may have been a lousy husband but he was an excellent mechanic so I always relied on him to at least ask about my cars and our son was pretty handy and mechanical also, but he died of a drug overdose 3 1/2 years ago just after his 32 birthday so his dad and I don't talk much anymore, plus he switched from auto engines to boat engines as he found them a lot easier. I believe that what makes a good mechanic beyond training is having a good touch along with experience kind of similar to a massage therapist. They can have all kinds of training/education but it takes having a good touch to be a really good massage therapist. Anyway, a friend of mine was here today checking the fuses and relays and reset things to get that light off and said I need to drive another 30 miles or more to see if it comes back on. Last time I had it smogged 2 1/2 years ago, it failed the first time and they told me to drive it 500 miles and come back to retest it. I drove 250 miles and then put that guaranteed to pass smog stuff in it and went back in and it passed. They no longer sell that around here at any of the parts places. I hadn't thought beyond the getting the light off so I can get the smog and registration taken care of but I guess that will be the next step and I hope to find a mechanic around me here that I feel I can trust to do good work at a decent price. I will report back once I see if I can get past the smog. Thank you very much for replying and I believe you quickly resolved this sensor off with the iPad thing. Boy do I feel like a knucklehead, especially since I was acting like little miss auto techy herself! Heheh

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Wednesday, March 31st, 2021 AT 11:59 PM

ASEMASTER6371