Newer MB 600 watt electrical fan in a m103
 

So I am close to having this project completed. I did a test to run the fan on the stock connectors and I need to beef everything up. I'm thinking of wiring it up on it's own circuit and just attaching it to the temp switch. Does anyone happen to have a wiring diagram for the fan for a w203 or I guess any of the models that have the Temic fan controller?

M4/7
http://benzbits.com/w203/FrontSAMWiring.pdf

Not cheap but installation looks easy - https://www.amazon.com/Derale-16795-PWM-Fan-Controller/dp/B00N0N75TI

How about a simpler Volvo two-relay controller with low speed for AC (existing aux fan trigger) and high speed over a coolant setpoint?

Is your alternator up for an extra 20 amps while idling?

Sixto
98 E320s sedan and wagon
02 C320 wagon

I've had this fa for a good 2 years already and it's output seems comparable to a viscous fan that is engaged at about 2500 - 3000 rpm. I actually don't care so much about settings and controllers or whatnot, just want the fan to turn on when temp gets to a certain point. If I knew a bit more about how this fan functioned I'd just cut off the controller and wire it in so that it comes on when temp is 91C (existing temp switch) and when the ac turns on, that's it.

So just do that. It's not complicated.

Was wandering about the Volvo two relay controller for our cars, that's what I installed in my Volvo 780 when I converted to an electric fan. I hooked it up directly to the radiator as that's where the switch is. Worked like a charm.

Volvo 240 owners use the switch from a Saab 900, that's installed by cutting the upper coolant hose. Some Jaguar XJ owners use the same switch.

That specific fan isn't easy to control. It has 8 speeds and is controlled by a 3volt plusewidth signal. 10% PWM = off, 20% = first speed, 30% 2nd speed, ect until 90% =100 % fan speed.


I built this fan into a 124 fan shroud and use my PCS trans controller to provide the PWM signal v/s coolant temp. It works really, really well. The temp needle never uncovers the top of the 8 on the 80C marking.

Buying a PWM standalone fan controller would be worth it to use the 600W fan. The viscous fan clutch setup on these cars is absolute crap.

How did you do your set up? Also, is it possible to just wire in the fan to temp switch and a/c pressure switch and ditching the control unit? Do you know what the 4 wires are for? I know + is red and orange or brown is negative, but what is the black and white one and the blue and yellow one used for?

I am unsure if I can or if it would render the fan useless. Also, I need to figure out what I can wire it to. It has so much power I cooked a 12 gauge wire and had a 10 gauge smoldering on the negative side. I tested it with different fuses starting at 10 amps and worked my way up. It blew every fuse within a few seconds up to a massive 50 AMP fuse I had which seemed to do ok. So I think I may need to get a large 100 amp relay and some thick wires. I think the + and - wires on the fan are maybe 4 or 6 AWG

Grab the starter relay from an old Ford truck.

From what little I remember, p = i^2 r = v i. 600 Watts / 12V = 50 amps so your fuse experiment is right. Better get a 60 amp fuse in case the alternator can’t keep up on a hot day.

Bulk quality wire is available from any MB with the battery in the trunk or under the rear seat. The W140 has a variety of lengths with terminals from the distribution center in the passenger footwell.

Sixto
98 E320s sedan and wagon
02 C320 wagon

I've been wanting to do this for a while and have been researching the options. The following thread has some good info:
Monster electric cooling fan upgrade. long. w/photos. | Moparts Question and Answer | Moparts Forums

And there has been a controller made for this fan: http://ma-uav.com/FanControllerv3.html.
The discussion about the controller: http://board.moparts.org/ubbthreads/ubbthreads.php/topics/1128594/1.html

This is it. So the thick + red wire and the thick - brown wire don't function unless 12v is put to the smaller black/white wire. That's what I needed to know. That makes it a little easier, now I believe I can wire that smaller one to the stock set up and wire the larger ones to thicker +/- posts.

I may be the first person that has fitted the newer my fan to a m103 engine. I will post pictures later.

Another iteration of the electric fan install on your 190E? I'm also still working on increasing cooling capacity, adding an oil cooler (stock 190D 2.5/300D 2.5) and trans cooler (Sienna) on my mom's car before I figure out something for mine.

Yes, but this time I was able to get the real deal. 600 watt MB from a w203.

I think I have one of those in my garage. Definitely show how to get it in there if you can!

The w203 fan is a monster. Does it fit between the 2.6 engine and radiator?

Yes, I made it fit. Its not crazy hot outside today. We are only at 105F with about 34% humidity. So far the temp remains about 85C with ac in stop and go traffic. I need to see how it will work once we hit around 115 dry heat. I did notice that without the 2 front aux fans, the temp is lower. Obviously because the condenser and radiator aren't blocked. But even when the 203 fan is off, the temps still seems to climb a lot slower than with the aux fans in front. Oh....and if you thought the 2 small aux fans were loud at high speed, the car now sounds like a plane idling on the runway. It's probably about 10 times louder than the 2 small aux fans.

Nice, got any pics? What alternator are using? What's your voltage at idle with the fan going? The C320 has a 120a or 150a alternative depending on options. And yes at full tilt that thing sounds like a cfm56 at ground idle.

Please share the wiring scheme you used?

I have wired up a very slim spal branded puller fan in a W124 300E, I used a standalone controller which was pushed into the radiator fins with a plastic tooth thing.

It was a variable speed that way and had a bypass to go full speed once the A/C starts - it really kept the temps down - but sounded like a banshee.

the big MB fan from a later model is not supposed to be run at full power for more than a few minutes I think, the motor heats up very badly.

I'm very interested in seeing the W203 fan mounted between the W201 radiator and the M103 engine.

Does anyone know what this blue/green wire is for? It's the connector that goes into the fan controller so it is part of the w203 wiring harness?

I believe the green/blue wire is the trigger, though I can't tell you how it operates.

Which green wire? the one in the plug or the one bundled up? Or are those the same wire I'm looking at? Picture is dark.

Here is a pinout of the connector

http://www.peachparts.com/shopforum/...=1&d=153143600

Its the PWM signal wire. The other smaller wire is the circuit 15 connection. When circuit 15 has power and there is no PWM signal the fan defaults to 100% on. A 10% PWM signal is needed to hold the fan off when circuit 15 is present.

Ok, got it. It's the speed controller.

600 watt MB fan in a m103 is a beast!
 

Ok guys here's a video of the fan in action. I am still cleaning up the wiring and what not. Since this video, I have added a second battery in the trunk just to manage the starter and added a 500 amp battery isolator. This video just shows the fan in action on a 117 degree day, sitting idle, with a/c on. The needle never moves past the 90C mark. To save you all some time, I turn the a/c on at about 2:05 and record the remaining footage monitoring the needle. Several minutes pass and the needle actually drops the temp down a bit. I was considering adding or finding a pwm to control fan speed, but I actually think I'm going to just leave it as is. It is on the same set up as the stock fans. However, I did wire it in to the thermoswitch so that it turns on at about 91C. I also still have the manual in-cabin switch as well. Quite honestly, removing the 2 aux fans from the front, I have noticed the engine runs a lot cooler, even without the 600 watt running. So far, the only issue that I did notice (which caused me to add the second battery) was that when I shut the engine off, once the engine temp began to rise, the aux water pump and fan would both turn on to bring the temp back down. This caused a bit of an issue with battery drain, nothing major because I am running a Bosch AGM, but the semi-slow crank on start up made me realize that It would be a good idea to isolate a second battery and starter so I wouldn't ever be left stranded. So that was about the only issue, which has been pretty much fixed to my satisfaction. I still may take an additional precaution and add a diode inline to the secondary + battery terminal to prevent drain at low idle speed and also a secondary + cable going to the starter with another inline diode so that the 2 are completely isolated from the rest of the system. So only power going to the secondary battery while engine is running or KOEO, and power only leaving secondary battery during cranking.
https://photos.app.goo.gl/4GB3WM9Bx9ao2u3g8