Questions about dealer-installed aux. transmission cooler

[Firstgenfanantic]

How many 1st gen owners out there have them?

What are your opinions about them? These auxilary coolers were installed under the driver's side bed and were wired to come on when a thermal switch closed.



I have one on my 93' W250 and want to know how to properly wire in a manual toggle switch to control the cooler fan. What kinda wire gauge can be used, type of relay, and toggle switch?

 

[Tippin Spotted Cow]

Had one. Worked intermittenly. Fell off while offroading. Bungee strapped it up. Fell off again when ramming through snowbanks and severed the transmission lines. Poured out more fluid in 10 seconds than I've ever seen before or since. Bypassed the cooler and ripped it out.

 

[Shadrach]

I know a salesman at the local Dodge dealership who has one on his 93 D350 Dually. It is used only " on highway" for towing his RV trailer and he told me he likes it. Shadrach

 

[boatpuller]

I'm of the KISS mentality(keep it simple stupid) so I didn't bother with relays, just ran some heavy wire(guessing it was 6 or 8 gauge) to a heavy duty switch I mounted in the seat frame of the drivers seat to keep the wire runs short. Just conected the wires in to the wires that go to the temp switch, there is always 12 volts at the cooler, it is controled by the temp switch, it will run with the ignition off. The cooler I added on the passenger side that gets the hot fluid first I left thermastatically controlled.

 

["Mad Max"]

Have one on the tug boat, and I'm installing one on my trail rig (6BT/518 Ramcharger). Good stuff. The dealer installs are a bit crude but they definitely work.

 

[Greenleaf]

I **JUST** installed one.



I removed that thermo switch and installed a pipe nipple there. I plugged the back port. The lines run into/out of the front of the cooler now as opposed to one line running all the way a round the back side.



I installed a 30 amp relay next to the other three. I control the relay via a dash mount switch. I ran a 10 gauge "positive" wire back to the fan motor and use a ground wire from motor to frame rail.



Everything is tied up and covered with split loom.



The factory heat exchanger is MIA. I still use the factory radiator mouted ATF cooler.



I don't use it. It is only for bragging rights that I have mounted a factory cooler. I don't tow.

 

[Firstgenfanantic]

I'm of the KISS mentality(keep it simple stupid) so I didn't bother with relays, just ran some heavy wire(guessing it was 6 or 8 gauge) to a heavy duty switch I mounted in the seat frame of the drivers seat to keep the wire runs short. Just conected the wires in to the wires that go to the temp switch, there is always 12 volts at the cooler, it is controled by the temp switch, it will run with the ignition off. The cooler I added on the passenger side that gets the hot fluid first I left thermastatically controlled.

Caleb,



I was thinking about doing the same thing. I was only worried because some 1st gen folks have warned me that the fan draws some decent amperage. I really believe this fan will help lower my trans temp while pulling. I plan to pull my new 5th wheeler in just 3 weeks over the Cascades. I want to make sure I get maximum cooling. The new converter/shift kit worked wonders... ... . but it still remains hot during stop & go driving.

 

[Greenleaf]

That stop and go is when my trans temp really climbs. If I move down the highway, it will remain cool. When I stop, it climbs right up to 170 or 180 w/o the under bed cooler.

 

[PToombs]

I got a cooler and switch from Summit for my buddies F550. I put the cooler behind the cab, in front of the rear wheels. (Where it would go on a pickup). I put the switch in the cooler hot line just before it goes in the radiator. When the temp starts to climb, the fan kicks on, and the transmission is getting cooler oil before the hot stuff even gets to the aux cooler. It works great. His temps used to get to 210 and 220, now it barely goes over 190 when he's towing heavy.

I just wired in a relay to run the fan, direct thru a fuse from the battery.

 

[Firstgenfanantic]

I installed a manual toggle switch for my aux. cooler fan last weekend. It did not take very long and the results were great! The only thing I noticed is that the voltmeter jumps and dash lights slightly flash when the fan gets switched on. Once the fan is running, the lights stay normal brightness and the voltmeter stays still at a normal range. I think this should be a good setup.

 

[PToombs]

Do you have a relay in there someplace? If not, I would strongly suggest adding one in, since the lights flicker.



Although on 2nd thought, it could just be the alternator taking up the extra load.