Cooling AC condenser at idle

[1970 CST Short Wide]

What are you guys using to cool the AC condenser at idle when running electric fans. I can put another fan in front of condenser and wire it in but only have room for a small 10" fan so it would only cool the center
Any input would be appreciated
Thanks
Steve

[knomadd]

You typically don't have a separate fan or anything for the A/C condenser. The condenser is intended to be close enough to the radiator that the fans pull air through both the radiator and the condenser. I'm not sure on the spacing, but I believe it's around a half inch or less. Also, your electric fan should have a shroud around it for maximum cooling, instead of just open all the way around the fan.

here's an example of the fan/shroud setup I'll be running in my 71.

[1970 CST Short Wide]

Originally Posted by knomadd

You typically don't have a separate fan or anything for the A/C condenser. The condenser is intended to be close enough to the radiator that the fans pull air through both the radiator and the condenser. I'm not sure on the spacing, but I believe it's around a half inch or less. Also, your electric fan should have a shroud around it for maximum cooling, instead of just open all the way around the fan.

here's an example of the fan/shroud setup I'll be running in my 71.

I have that basic setup already but my fan doesn't come on until ~195 and keeps the engine temp between 195 - 205. Thinking this is to hot at idle for condenser???? I'm I over thinking????

[dayj1]

Originally Posted by 1970 CST Short Wide

I have that basic setup already but my fan doesn't come on until ~195 and keeps the engine temp between 195 - 205. Thinking this is to hot at idle for condenser???? I'm I over thinking????

Google "ac trinary switch". It sounds like maybe you don't have one. It turns on the cooling fans based on the pressure in the AC system and, without it, you'll likely split one of the soft lines.

[Overdriven]

Another option is to have one of the fans turn on when the ac comes on regardless of engine temp. Many more modern vehicles do this, turning on one of the dual fans or in the case of a single two speed fan turning the fan on to low. They do this to get some airflow through the condenser at all times, limiting heat soak and keeping the air coming out of the vents cool. Then, if and when engine temp gets hotter the second fan turns on or kicks the single two speed fan into high.

I wouldn't bother with a 3rd pusher fan if you already have a dual fan setup with a shroud. Instead install a trinary switch or wire up a fan to come on with the ac. Also try to make sure the condenser has a decent seal around the edges to the radiator. This way air being pulled through the radiator goes through the condenser instead of sneaking in between the condenser and radiator.

[knomadd]

yep, what they said! Trinary switch is a must. As for 195-205 temps, that's nothing to worry about. Since at least the 90's engines have been designed to run about 210 all the time. Older engines can do it too, but I've been told by the older generation hot rodders that it's ideal to be between 185-200 for normal operating temps on older engines. I don't worry about the temps until they creep up above 225.

[1970 CST Short Wide]

Originally Posted by dayj1

Google "ac trinary switch". It sounds like maybe you don't have one. It turns on the cooling fans based on the pressure in the AC system and, without it, you'll likely split one of the soft lines.

I have the Trinary switch just didn't want one of the Rad fans on all the time, I want the 195-200 eng temp. The thought was to run a fan in front of the condenser off the trinary so it comes on at idle
I guess my ? Is - Is this to much

[dayj1]

Originally Posted by 1970 CST Short Wide

I have the Trinary switch just didn't want one of the Rad fans on all the time, I want the 195-200 eng temp. The thought was to run a fan in front of the condenser off the trinary so it comes on at idle
I guess my ? Is - Is this to much

I think it's too much. There's no need to add a third fan. I get what you're saying about not wanting to cool your engine temp below 195, but the stock thermostat is 190* and no amount of airflow is going to make it run cooler than that.

[clemsonteg]

I have a trinary switch which engages both fans when the pressure in the system triggers the switch. I have considered wiring one fan to the switch and the second fan to run when the compressor engages, but I haven't done anything with it to date. Mine seems to work fine at idle, but it could always be better.

[1970 CST Short Wide]

Originally Posted by clemsonteg

I have a trinary switch which engages both fans when the pressure in the system triggers the switch. I have considered wiring one fan to the switch and the second fan to run when the compressor engages, but I haven't done anything with it to date. Mine seems to work fine at idle, but it could always be better.

How do you wire it to have the trinary kick on the fans AND the ecm kick on the fans ?.

[davepl]

I put a slim 12" fan between the radiator and AC condenser. This was more to help with cooling at idle, but of course benefits the AC as well. I wired mine to a temp sender for coolant, not the AC.

[ls1nova71]

Originally Posted by 1970 CST Short Wide

How do you wire it to have the trinary kick on the fans AND the ecm kick on the fans ?.

The ECM sends a ground to the fan relay to turn the fan on, so you just ground one side of the trinary switch and wire the other to the ground for the fan relay that way either ground will turn the relay on. You may get a check engine light though because the ECM sees the relay grounded but it didn't command it. You can have the error reporting for it turned off in the tune though.

[1970 CST Short Wide]

Originally Posted by ls1nova71

The ECM sends a ground to the fan relay to turn the fan on, so you just ground one side of the trinary switch and wire the other to the ground for the fan relay that way either ground will turn the relay on. You may get a check engine light though because the ECM sees the relay grounded but it didn't command it. You can have the error reporting for it turned off in the tune though.

Cool, thank you. Think I'll give this a shot
Thanks again
Steve

[1970 CST Short Wide]

Originally Posted by ls1nova71

The ECM sends a ground to the fan relay to turn the fan on, so you just ground one side of the trinary switch and wire the other to the ground for the fan relay that way either ground will turn the relay on. You may get a check engine light though because the ECM sees the relay grounded but it didn't command it. You can have the error reporting for it turned off in the tune though.

All Done. This worked perfect. I now have Ice Cold AC. Love it
Thanks for the input