Trans cooler with fans, what's the best way to wire them.

[industrialfish]

I have a small 5"x10" transmission cooler (12k gvwr) that I plan on running in line with the factory one and want to mount in the fender wall because it has 4 5x5 fans so I won't need airflow, and that I want to keep out of the elements (1.44amps total, so about 20watts, won't need a relay).

IIRC from the radio install, the 04+ doesn't have a switched 12V line for accessories right? Should I wire them to come on with the radiator fans, or is there a switched 12V line under the hood that I can tap into, such as the running lights, that won't bother anything?

[BillBoost37]

Seems that you don't want them on in the middle of the winter, so ... I'd tap into the fans as a trigger and use a relay even though they take no power.

[industrialfish]

Thanks Bill, that is what I was thinking. I have a quartet of 500mA micro relays I can use. The radiator fans are just 12V on/off fans right? Not variable speed or anything funny?

[BillBoost37]

I am unsure in 05

[91parkave]

If you don't have airflow in the first place a fan on your trans cooler isn't going to help anything... You could just go buy the proper sized cooler and install it stand alone and make it more efficient than having a cooler in line with no airflow drawing unnecessary electricity

[Scottydoggs]

if you really think you need the fans id use a relay. cause your battery will take a strain if you dont. wire them up like fog lights to a on off switch thats powered when the car is on only. this way you can turn the fans off in the winter time. ( how i did my gmc trucks electric cooling fans after the clutch fan took a 3 rd dump on me.)

you will need some air flow where you mount the cooler or it will just be a hot box with hot air and do very little for cooling.

[blueguy]

I would think mounting the cooler down on the bottom of the radiator, behind the lower grille/valance would be ideal, or behind the upper grilles...those would be the only places I'd consider with decent airflow to them.

[industrialfish]

The fender wall should have adequate ventilation to prevent it from being a hotbox, or people wouldn't put intakes there. Although I may mount it where the stock intake/pcm was, there is plenty of open air there and away from the elements. I'm more concerned with stop&go traffic where I'm not seeing any sort of airflow anyway which is why I'd like to have fans running when the car is, cooling when not moving.

Wiring to the radiator fans seems like the best bet since if those are on the transmission is probably getting warm too and nothing to have to change over come winter.

[Russosaur]

That sounds like a good idea unless you have stock fan turn on temps/tstat because its still gonna be 210+ temps leaving the rad and I doubt that fans will cool off the oil that much on the cooler but I could be underestimating the cooling abilities greatly. I say just run a relay with a switch hidden in the console or something you can flick on when temps start rising. Any specific reason not to just mount it like a regular trans cooler? The fans are nice but even if you get in traffic and the rad fans kick on it should still pull air through it no?

Sent from the Milky Way

[91parkave]

I had the biggest cooler I could fit in the fender well area back when I got the car. But you will only get 20% surface area coverage of air to actually pass over the radiator. Very inefficient. With that being said you should seriously consider what you're doing if you're trans cooler was mounted like most cars with it in front of the ac condenser you would then have airflow from the huge opening in from plusyour cooling fans drawing air through them.

As an example here's my old setup which later got a fan mounted but did me no good. This is for a rv BTW.




But it has nothing on my new setup which is stupid simple cheap and 100x more efficient

[industrialfish]

That sounds like a good idea unless you have stock fan turn on temps/tstat because its still gonna be 210+ temps leaving the rad and I doubt that fans will cool off the oil that much on the cooler but I could be underestimating the cooling abilities greatly. I say just run a relay with a switch hidden in the console or something you can flick on when temps start rising. Any specific reason not to just mount it like a regular trans cooler? The fans are nice but even if you get in traffic and the rad fans kick on it should still pull air through it no?

Sent from the Milky Way

Mostly my reason for mounting it remotely is that I want to avoid the fans getting wet/dirty. When my air dam was broken my car ran hot until I replaced it so I don't want anything in front of the radiator that could impede it's airflow again either. Also this cooler isn't meant to be a stand alone replacement for cars that already have coolers. Since it's new, I already have it and all the hardware to mount it and the fans, so I'm not trying to go buy different one.

I figured that with a stock 195* thermostat my transmission shouldn't be running at 215* ALL the time, but I didn't know our fans don't come on until 210*. So I think I will relay the fans off an unused switched fuse location and just remember to disconnect it during the winter.