Question: Electric Radiator fans

[Enricor99]

Hi,

Wondering if you can help

Here are the pictures of the thermostat( for the electric fan) and the fan itself for my 81 vette. The fans do not come on even though the temp goes over 200 Fahrenheit ‎. I did turn the switch on the thermostat and they did come on (once) but they don't come on consistently. The thinking is that maybe a new thermostat for the fan is required. ( I included a picture of it). I also included a picture of the actual fan which has a model number.
Any help would be appreciated

 

[Antz81]

Looks like you've installed your own thermostat for the electric fans.
how did you wire this?
Is is on the + side of the fans or the negative?
the stock thermostat doesn't switch then fan on until around 230degrees. This is wired on the negative side of the fan. If you've left this connected that may explain your problem

 

[6880 Mike]

I'm confused. All 81s had an electric auxiliary fan from the factory. It used a temperature sensor on the rear of the passenger's head and required no thermostat.

 

[kpic]

As 6880 Mike is confused and he isn't confused easily, I'll ask a dumb question; is it a GM fan or an aftermarket one? I did a search for "y704-9 electric fan" which is what Flex-a-lite uses.

Hits:
About 1,830 results (0.38 seconds)
Search Results
Flex-a-Lite Automotive Home page www.flex-a-lite.com/ Flex‑a‑lite Consolidated Flex-a-lite invented the Flex Fan and holds the patent for the first electric fan for the automotive ... 03-07 Super Duty Flex-a-lite Radiator and Fan Combo ...
[SOLD] Flex-a-Lite 15" electric radiator fan - Mopar Mechanical ...

www.forabodiesonly.com › ... › Mopar Mechanical Parts For Sale
Jan 20, 2012 - 7 posts - ‎2 authors
I have a nice used Flex-a-lite electric radiator cooling fan for sale. ... the housing or anywhere, just on the electric motor itself - Model Y-704-9.

 

[Enricor99]

As 6880 Mike is confused and he isn't confused easily, I'll ask a dumb question; is it a GM fan or an aftermarket one? I did a search for "y704-9 electric fan" which is what Flex-a-lite uses.

Hits:
About 1,830 results (0.38 seconds)
Search Results
Flex-a-Lite Automotive Home page www.flex-a-lite.com/ Flex‑a‑lite Consolidated Flex-a-lite invented the Flex Fan and holds the patent for the first electric fan for the automotive ... 03-07 Super Duty Flex-a-lite Radiator and Fan Combo ...
[SOLD] Flex-a-Lite 15" electric radiator fan - Mopar Mechanical ...

www.forabodiesonly.com › ... › Mopar Mechanical Parts For Sale
Jan 20, 2012 - 7 posts - ‎2 authors
I have a nice used Flex-a-lite electric radiator cooling fan for sale. ... the housing or anywhere, just on the electric motor itself - Model Y-704-9.

It is a aftermarket fan

 

[Enricor99]

Looks like you've installed your own thermostat for the electric fans.
how did you wire this?
Is is on the + side of the fans or the negative?
the stock thermostat doesn't switch then fan on until around 230degrees. This is wired on the negative side of the fan. If you've left this connected that may explain your problem

I really appreciate you taking the time to answer

I never installed this myself and don't know how it was wired. I don't even know much about wiring to even answer it. All I know is that it worked before and now it doesn't. All that happen was that I recently got the car thermostat change at the garage by a mechanic. And Like I said, when I realized they were coming on, I tested it by leaving the engine idling, getting the engine temp up to 200 Fahrenheit and I turned the switch on the thermostat(for the fans) and the fans did come on once and once only. It leads me to believe that the thermostat for the fans is bad which is depicted in the picture

Your answer leads me to believe that you think that the wiring was done incorrectly...am I understanding that correctly?

 

[Antz81]

I am assuming that this is an aftermarket replacement for the original electric fan.
the original thermostat is where 6880 mike described, it will have a black wire and a blue wire going to it. If you short these two wires (either at the thermostat or the 6pin connector the the starter extension harness if its easier) as well as checking your thermostat as you did before and it works then the original thermostat is still connected. (From what you described it still is). If this works then i would remove the added thermostat.
just be aware that the original comes in at a higher temp and is based on the engine temp, not coolant temp.

 

[Enricor99]

I am assuming that this is an aftermarket replacement for the original electric fan.
the original thermostat is where 6880 mike described, it will have a black wire and a blue wire going to it. If you short these two wires (either at the thermostat or the 6pin connector the the starter extension harness if its easier) as well as checking your thermostat as you did before and it works then the original thermostat is still connected. (From what you described it still is). If this works then i would remove the added thermostat.
just be aware that the original comes in at a higher temp and is based on the engine temp, not coolant temp.

Does the engine thermostat work in conjunction with the thermostat for the electric fan. When I say the thermostat was replaced, I mean the thermostat for the engine and not the coolant thermostat associated with the electric fans .

 

[Antz81]

Does the engine thermostat work in conjunction with the thermostat for the electric fan. When I say the thermostat was replaced, I mean the thermostat for the engine and not the coolant thermostat associated with the electric fans .

The thermostat for the electric fan is totally independent.

 

[Enricor99]

The thermostat for the electric fan is totally independent.

I am have narrowed it down to thinking it is a faulty thermostat for the electric fan. My question now is ....can I just purchase any type of thermostat( not knowing what brand/type my electric fan is..... or are there different types of thermostats that are proprietary?

 

[Antz81]

Just checked the specs of the stock thermostat for the electric fan. The switch closes at ~238 degrees, and opens at ~201 degrees.

Which thermostat are you replacing?
If its the stock thermostat on the engine block you'll be fairly limited in your options i think.
It shouldn't mater what thermostat you end up with as long as it works and can carry the current of the fan.
You'll also want to be sure that it will switch the fan on at the same temp (or a lower temp) than stock.

 

[Peer81]

I changed my coolant water thermostat tp 180F and the electric fan thermostat to 190F. Works perfect for me!

And yes there are some different types so just buy a good one from a corvetteparts guy

Greetings Peter

 

[Vettehead Mikey]

Hi,

Wondering if you can help

Here are the pictures of the thermostat( for the electric fan) and the fan itself for my 81 vette. The fans do not come on even though the temp goes over 200 Fahrenheit ‎. I did turn the switch on the thermostat and they did come on (once) but they don't come on consistently. The thinking is that maybe a new thermostat for the fan is required. ( I included a picture of it). I also included a picture of the actual fan which has a model number.
Any help would be appreciated

The factory setting for the fan to come on is 238*F, so I think you're trying to fix something that's not broken.