Installing electric fan with Vintage Air

[7tredmach]

I would like to install a electric fan on a restored 72 C-10 with Vintage Air. I am going with the 16" straight blade fan from Be Cool. Do I need a controller that connects to the AC, so the fan runs the entire time the AC is on? Or do I use a controller that comes on and goes off at a set temperature?
Great pics of Chevy Trucks on this site.
Thanks for the info.
Paul

[theyammieguy]

Originally Posted by 7tredmach

I would like to install a electric fan on a restored 72 C-10 with Vintage Air. I am going with the 16" straight blade fan from Be Cool. Do I need a controller that connects to the AC, so the fan runs the entire time the AC is on? Or do I use a controller that comes on and goes off at a set temperature?
Great pics of Chevy Trucks on this site.
Thanks for the info.
Paul

The fan should never run the entire time the a/c is on. High pressure kicks the fan on.

[Kid]

per vintage air instructions, you should run a trinary switch in place of the binary switch (pressure safety switch). I believe it turns on your fan when pressure starts to build

[1tigers]

You can tap off compressor hot wire to a relay. Fans will run when compressor is cycling.Fans run during entire compressor cycle

[bigsnookmaster]

I'm running the trinary switch with no problems.Fans come on as soon as you turn the a/c on.

[big_al_71]

I am running flexlites and they come with a thermostat that goes in the radiator fins, they come on as soon as the coolant reaches a certain temperature that you set. Truck so far runs at 160 degrees all day long and the a/c blows at 37degrees, in the hot florida weather.

[jaros44sr]

Originally Posted by big_al_71

I am running flexlites and they come with a thermostat that goes in the radiator fins, they come on as soon as the coolant reaches a certain temperature that you set. Truck so far runs at 160 degrees all day long and the a/c blows at 37degrees, in the hot florida weather.

Any more info on the thermostat in the rad, also on the controller

Nice engine, big al

[project1971]

you should have your fans running all the time with a/c on. if they waited for high pressure to kick on your a/c wouldn't cool worth a poop.

[theyammieguy]

Umm, your wrong on that. The system is designed to build high pressure on the high side usually around 250psi. Then the high pressure switch sends the signal to the fan to turn on.

If they designed it to be on all the time, there would be no need for a high side in the system thus you wouldn't create the pressures needed to condense the refrigerant back into a liquid.

[project1971]

I don't mean to be an a$$ but no im not wrong. it should kick in a high speed or secondary fan too cool it back down from the high pressures. you don't want the condensor running that hot all the time your a/c will not perform properly. The less heat it has to transer the better it will cool. the orfice or expansion valve is what changes the gas state to liquid. NOT saying you can't running that way but would be more efficent especially if running 2 fans or 1 fan with 2 speeds to run the 1 fan or low speed when a/c kicks on and 2nd fan or high speed when a/c pressures get high or engine temp gets too hot.

[theyammieguy]

Originally Posted by project1971

I don't mean to be an a$$ but no im not wrong. it should kick in a high speed or secondary fan too cool it back down from the high pressures. you don't want the condensor running that hot all the time your a/c will not perform properly. The less heat it has to transer the better it will cool. the orfice or expansion valve is what changes the gas state to liquid. NOT saying you can't running that way but would be more efficent especially if running 2 fans or 1 fan with 2 speeds to run the 1 fan or low speed when a/c kicks on and 2nd fan or high speed when a/c pressures get high or engine temp gets too hot.

Im not trying to be rude but do you know anything about an a/c system?
The purpose of the expansion valve or orfice tube is to meter the flow of the refrigerant. The evaporator is what changes the liguid to gas(hence the word evaporate). The freon leaves the compressor as a high pressure gas and hot, goes through the reciever/drier, then passes through the condensor where it is condensed into a liquid still under high pressure. It's now warm not hot. It then goes through the expansion valve or orifice tube still a liquid, passing through the expansion valve the freon suddenly drops in temp from warm to cold. Then it passes through the evaporator core where the blower fan passes cold air through the fins. The evaporator turns the liquid into a gas so it can re-enter the compressor because we all know liquids can't be compressed.

Now with that said, if you wire the fan to constantly run while the compressor is on, you will shorten the life of the compressor and more than likely the fan. When the refrigerant reaches a high enough pressure the high pressure switch sends a signal to the fan to turn on but it also cuts the clutch off on the compressor. This cycling of the compressor is what the system needs to do to run properly and effecient If your fan is constantly running, the compressor in return will constantly run.

To the original poster of this thread, I suggest running the system like the highly paid engineers designed it run.

[see ten]

I'm running Flex-a-lite 295 electric fans on two of my trucks. The controller for the fans has a provision for A/C. A wire is piggybacked off of the wire that engages the clutch on the compressor. Here's a link to Flex-a-lites page with instructions. Skim down to the 295 and it will pull up the instructions detailing the install. http://www.flex-a-lite.com/auto/html/instructions.html The fans run when the engine reaches the predetermined engine temp and they also run when the clutch is engaged. All the piggybacked wire does is send a signal to the controller so the fans kick on. I see no way that having them wired this way would cause one or the other to wear out quicker. Of course what the heck do I know?? I work on an assembly line building ranges not servicing A/C systems. I do know that I've got two trucks that I've been running like this for years and they've both got cold A/C and they don't run hot. If you two want to keep arguing, come on over! I've got some beer in the shop fridge ya'll are welcome to it! I'll just sit and watch! Peace guys!

[PipsC10]

Thanks guys for your detailed lesson on how an ac system works. Honestly, I learned a lot from this thread. If I was in Georgia I would come over to see ten's house and drink his beer!

[67ChevyRedneck]

Originally Posted by see ten

I'm running Flex-a-lite 295 electric fans on two of my trucks. The controller for the fans has a provision for A/C. A wire is piggybacked off of the wire that engages the clutch on the compressor. Here's a link to Flex-a-lites page with instructions. Skim down to the 295 and it will pull up the instructions detailing the install. http://www.flex-a-lite.com/auto/html/instructions.html The fans run when the engine reaches the predetermined engine temp and they also run when the clutch is engaged. All the piggybacked wire does is send a signal to the controller so the fans kick on. I see no way that having them wired this way would cause one or the other to wear out quicker. Of course what the heck do I know?? I work on an assembly line building ranges not servicing A/C systems. I do know that I've got two trucks that I've been running like this for years and they've both got cold A/C and they don't run hot. If you two want to keep arguing, come on over! I've got some beer in the shop fridge ya'll are welcome to it! I'll just sit and watch! Peace guys!

This is how I did my S-10. Works well.

I want to do the "Jeep" fan upgrade to my 67 soon, and I will purchase the same kit again to use with my V/A kit.

[1tigers]

Project1971 is right .I've been working on hvac for 30 years and a high pressure switch [high limit switch] cuts the system off when there is a problem .The thermostat cuts the compressor on and off. Not the high limit switch.Fans run the entire compressor cycle.

[theyammieguy]

Well hell guess I'm wrong. Oh well, no strife here. I'm on my way to seetens to bs about trucks. Lmao

[acl]

I don't know highside from lowside, inside from outside on an a/c system. I have vintage air with dual flexlite fans. Use the trinary switch from v.a as they suggest and have had no probs. My fans come on when my a/c compressor is on as well as temp control when not using a/c. I also have a manuel switch under the dash where I can run fans anytime I want to cool it. Have no Idea if this is right or wrong, it works flawlessly and kinda makes sense to me. (scary huh). My 2¢. Gary

[theyammieguy]

Hey guys, I just wanted to apologize if I gave out misleading information. I was basing my information on the trucks I work on and I assumed they pretty much ran the same way.

On tractors(macks and peterbilts and such) the fan does not come on with the compressor is engaged but waits for a signal from the high pressure switch.

Again I apologize for any confusion on my part.

[cparman]

I had a 16 Spal on my Chevelle, and hated it. It was too noisy, and would not keep up with the zz502 in the Florida summer. Went to a dual 11" setup. Much Quieter, and did the job here in NE Fl. As far as the controller? Trinary switch will work, but Spal make a sweet controller that you can program to do what you want.

[7tredmach]

Ok guys, Thanks for all the great info. Looks like I'll be installing the fan with a controller that uses a trinary switch.
Thanks, Paul

[Sammy]

Sounds like beer time to me.