95 cooling fans not working
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8th Gear
Joined: May 2018
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95 cooling fans not working
Hello all,
I know different fan issues have been discussed but unfortunately I can't find exactly what's happening to me and my electrical knowledge is quite limited so here goes:
The car seemed to be running hot last fall. If I was in traffic, the guage basically wouldn't stop climbing until I started driving. I think turning the heat on helped but can't remember for sure. I replaced the coolant temp sensor and ran the car up to temp in the driveway - both fans worked as advertised. They just didn't keep up with the heat. So upon revisiting this issue now that winter actually appears to be over in my area, neither fan is working at all. I turned the AC on - no fan. I ran the car up to temp and neither fan turned on.
All of the fuses are fine. One interesting thing tho is that the fuse for the relays is listed as a 5A but there was a 10A installed in mine. I've had the car for a couple of years and the fans had been turning on until now. What I think I know about electrical is that if it's wrong, it usually shorts something out pretty much immediately so I'm not sure if this 10A vs 5A fuse really hurt anything.
When I bought the car a few years ago, the owner said that the owner before him had wired the fan to run constantly. He said he disconnected that and replaced a relay and the fans worked fine.
I know different fan issues have been discussed but unfortunately I can't find exactly what's happening to me and my electrical knowledge is quite limited so here goes:
The car seemed to be running hot last fall. If I was in traffic, the guage basically wouldn't stop climbing until I started driving. I think turning the heat on helped but can't remember for sure. I replaced the coolant temp sensor and ran the car up to temp in the driveway - both fans worked as advertised. They just didn't keep up with the heat. So upon revisiting this issue now that winter actually appears to be over in my area, neither fan is working at all. I turned the AC on - no fan. I ran the car up to temp and neither fan turned on.
All of the fuses are fine. One interesting thing tho is that the fuse for the relays is listed as a 5A but there was a 10A installed in mine. I've had the car for a couple of years and the fans had been turning on until now. What I think I know about electrical is that if it's wrong, it usually shorts something out pretty much immediately so I'm not sure if this 10A vs 5A fuse really hurt anything.
When I bought the car a few years ago, the owner said that the owner before him had wired the fan to run constantly. He said he disconnected that and replaced a relay and the fans worked fine.
Thread Starter
8th Gear
Joined: May 2018
Posts: 8
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Is there a likely cause of neither fan working either at temp or with the AC on?
How would I test the relays and the fans to eliminate one or both of those as the problem(s)?
Thanks in advance for any advice.
How would I test the relays and the fans to eliminate one or both of those as the problem(s)?
Thanks in advance for any advice.
Le Mans Master
Joined: Oct 2004
Posts: 7,706
Likes: 485
From: Everett WA
C4 of Year Finalist (appearance mods) 2019
The odds that both fan motors are bad is very low. The odds that one of the 3 relays on a 95 are bad is much higher.
The odds that the PO rewiring job is screwed up are even higher.
There is no need for the fan to run all the time if the radiator is working properly. Do NOT use the analog gauge to determine water or oil temp always use the digital gauges.
Do you have the FSM for your 95?
The odds that the PO rewiring job is screwed up are even higher.
There is no need for the fan to run all the time if the radiator is working properly. Do NOT use the analog gauge to determine water or oil temp always use the digital gauges.
Do you have the FSM for your 95?
Thread Starter
8th Gear
Joined: May 2018
Posts: 8
Likes: 0
The odds that both fan motors are bad is very low. The odds that one of the 3 relays on a 95 are bad is much higher.
The odds that the PO rewiring job is screwed up are even higher.
There is no need for the fan to run all the time if the radiator is working properly. Do NOT use the analog gauge to determine water or oil temp always use the digital gauges.
Do you have the FSM for your 95?
The odds that the PO rewiring job is screwed up are even higher.
There is no need for the fan to run all the time if the radiator is working properly. Do NOT use the analog gauge to determine water or oil temp always use the digital gauges.
Do you have the FSM for your 95?
Unfortunately, no. I don't have the FSM.
As far as I know, the old wiring to have it run constantly was removed. I'm not 100% cuz I don't know exactly what was done. But the fans had been running normally for me for about 2 years since I bought it so I took that to mean it was fine. Obviously, I could be wrong.
Do you happen to have instructions on how to test the relays? Would 1 bad relay cause both fans to fail or would that require 2-3 relays to have died?
Thread Starter
8th Gear
Joined: May 2018
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Maybe a dumb question but the 3 fan relays - all 3 in my car are 5 prong. Only 1 harness is a 5 point connector while the other 2 harnesses are 4 point connectors. Is all of this correct? I have seen 4 prong relays for sale and now I'm wondering if I should have 2 of those instead of all 5s. Once again, the fans have been working for 2 years so that doesn't seem like a likely issue but I just wanted to verify.
Thread Starter
8th Gear
Joined: May 2018
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Update:
I've tested all 3 cooling fan relays and all test good.
I ran power to each fan and both of them ran.
All fuses are good, coolant temp sensor is new and the fans won't run either at temperature OR with the AC on.
I feel like the field of what's wrong should be pretty narrow but I don't have a clue what is left to test. Any suggestions would be much appreciated.
I've tested all 3 cooling fan relays and all test good.
I ran power to each fan and both of them ran.
All fuses are good, coolant temp sensor is new and the fans won't run either at temperature OR with the AC on.
I feel like the field of what's wrong should be pretty narrow but I don't have a clue what is left to test. Any suggestions would be much appreciated.
Last edited by 95vetteproblems; May 11, 2018 at 03:54 PM. Reason: Accidentally posted before finished
Advanced
Joined: Jun 2006
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Update:
I've tested all 3 cooling fan relays and all test good.
I ran power to each fan and both of them ran.
All fuses are good, coolant temp sensor is new and the fans won't run either at temperature OR with the AC on.
I feel like the field of what's wrong should be pretty narrow but I don't have a clue what is left to test. Any suggestions would be much appreciated.
I've tested all 3 cooling fan relays and all test good.
I ran power to each fan and both of them ran.
All fuses are good, coolant temp sensor is new and the fans won't run either at temperature OR with the AC on.
I feel like the field of what's wrong should be pretty narrow but I don't have a clue what is left to test. Any suggestions would be much appreciated.
Thread Starter
8th Gear
Joined: May 2018
Posts: 8
Likes: 0
I'm having similar problems with my 96 Collectors Edition. I took it to the dealer and they said there is a lot of debris in the condenser. I find it hard to believe that would be the issue since the temp climbs while at a stand still. I guess the debris could impinge the airflow from the electric fans. Anyway they wanted $500 just to clean the condenser. I though I'd take a stab at that myself.
If your issue is the same as mine, that'd be an interesting cause, like you said. My AC works, does yours? It just doesn't activate the fan like it should. I actually noticed last summer that the fan had a hard time keeping up with the heat if I was in traffic for a while. I suppose the condenser being clogged could've caused that so maybe I'll clean mine as well. I don't understand why it would prevent either of my fans from turning on though.
If you can report your results after cleaning the condenser, I'd appreciate it. If I happen to find anything, I'll do the same.
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Thread Starter
8th Gear
Joined: May 2018
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Since testing all of the relays and the fans and plugging everything back in, I was running the car again and something new happened. The SES light came on pretty much right away. Both fans came on at the same time. A few minutes later, the SES light and the fans shut off... few minutes after that, they all came back on.
With the light on, I tried to check the code. I have a simple scan tool that works with an app... it wouldn't read anything. I have a new question now. Did 95 corvettes have ODBII ports? Bc mine is shaped that way and my code reader plugs in but can't read the data.
So, without having been able to pull the code yet, anyone know what would cause the SES light to come on that would turn both fans on when they have no reason to be on? And does my car have the wrong ODB port somehow?
With the light on, I tried to check the code. I have a simple scan tool that works with an app... it wouldn't read anything. I have a new question now. Did 95 corvettes have ODBII ports? Bc mine is shaped that way and my code reader plugs in but can't read the data.
So, without having been able to pull the code yet, anyone know what would cause the SES light to come on that would turn both fans on when they have no reason to be on? And does my car have the wrong ODB port somehow?
Le Mans Master
Joined: Oct 2004
Posts: 7,706
Likes: 485
From: Everett WA
C4 of Year Finalist (appearance mods) 2019
Yes, your 95 has a obd-2 port but only obd-1 software.
Perhaps this will be of some help to you in pulling codes:
https://www.corvetteforum.com/forums...ies-video.html
Perhaps this will be of some help to you in pulling codes:
https://www.corvetteforum.com/forums...ies-video.html
Thread Starter
8th Gear
Joined: May 2018
Posts: 8
Likes: 0
Thanks!
Yes, your 95 has a obd-2 port but only obd-1 software.
Perhaps this will be of some help to you in pulling codes:
https://www.corvetteforum.com/forums...ies-video.html
Perhaps this will be of some help to you in pulling codes:
https://www.corvetteforum.com/forums...ies-video.html
