cooling fan
 

has anyone ever added a second cooling fan beside the original one? i was thinking i might add my spare one to run on a temp switch to further cool the condesor. has anyone ever attempted this? i noticed the newer 300ds and 300e's have 2. anyone wanna chime in and tell me if i shoud or shouldnt. i also plan to do the 120a alt. upgrade before doing this.

I was just going to mention a stronger alternator... make sure you upgrade the wiring too. With dual fans 134A may work a bit better...

im not planning to use 134 though. im still running r12. i just wanna make things cool even better. now ideally a parallel flow condensor and two fans would make for some cold vent temps.

I'm suprised there aren't any direct swap parallel flow condensors yet for these cars, it's make a potential conversion a lot better.

there are parallel flow condesors for these cars. but the lines running to them will need to mods. there are a few forum members that have done this mod.

But they're still not a "turn key" sort of kit... having to find parts to be made slows you down and makes you not want to deal with it.

I can only imagine a parallel flow with R12. :D

Before going to the effort and expense of adding the second cooling fan, consider replacing your existing electric fan and the viscous clutch on the engine fan. I recently replaced both on my 300SDL and I've been pleased with the cooling results. My car ran close to 90 before, but now runs almost at 80, even on warm days.

The electric fan in front, which is triggered by the refrigerant temperature, goes bad over time. I connected both the old one and the replacement to a 12V supply and was amazed at the difference! The old one ran like the cabin fan at low, while the new one ran like the cabin fan at high!

The viscous fan clutch on the engine fan tends to leak toward the end of its life. If you check the front of your fan and see a lot of dirt and grease, it's a sure bet that clutch is going.

The only problem with this is that the clutch and fan cost a lot of $$, even on FastLane. Since they are mission-critical, I would not buy them from eBay sellers. The electric fan is easy to replace. The viscous fan clutch either requires removal of the radiator, or a special stubby 8mm allen socket. I know this applies to the OM603 and M103 engines, and I believe the OM617 has something similar.

Also, make sure your cooling system is up to snuff. Not only does it remove heat from the engine, but it also removes heat from your refrigerant. When I replaced the radiator in my old 240D, I noticed a significant drop in the AC temperature to where it almost cooled the cabin. I really encourage you to ensure all the factory systems are working as designed before adding additional items.

ccooper is right about making other stuff work well first. However, I've also thought of doubling up on those fans. There's certainly enough room there - I've held up another to it and convinced myself that the original only needs to move over and down maybe 2".

my fan clutch is good,and so is my old electric fan. it runs just as good as a new one. as for the expense,i already have a spare fan just like it and i could get a temp switch for very little. this isnt to pick up the slack where the rest of the system isnt working,its to help get things even cooler(mainly the condesnsor) the cooling system works great,i have a 3month old radiator in it and i have flushed the whole system

i dont know
 

what the fans draw but the above post regarding upgrading your alternator may be worth looking into before doing the conversion. or perhaps you could just put it on a switch so you could turn it off and on.

tom w

thats the plan.

I figure 1A per 1" of diamter...

FWIW, my wife's car has a mod where the recirc is always on for the AC. I cannot imagine needing a cooler AC. On the hiway at 97 and muggy last week, I had to turn the fan on low manually it got so cold. Even in heavy traffic the same day I was comfortable.

Maybe that mod would be easier than an extra fan.