6.3

Hi.

I have a switch at drier in parallel with switch in thermostat housing too. I have never seen electrical fan running as the engine driven fan is enough to do the job. I'm in central Europe so our average summer temperatures are ~25C. California or Florida may be a different story.

The most important is to have your visco clutch working correctly as this is the main fan rpm regulator.

As mpmorris stated already early 6.3s were shipped without any aux electrical fan and it was OK too. One of my cars (#1285) was one of them, but it got aux fan with engine swap some time ago.

i believe that European cars were not equipped with emergency hood open switch (I hope you mean this one). There is no overpressure switch either.

Filip

300SEL 6.3 #1285 (1969 EURO version)
300SEL 6.3 #5346 (1971 US version project)

So, I need some advice. I had this very thing done. My car is 353 and I had the assembly from a later car They installed the switch on the drier and no switch in the thermostat housing. They also did not install the safety switch.
They insist that the one in the thermostat housing is just for back up to cool the engine A
and that the drier has to get very hot and then the fan comes on. This makes no sense to me. Located at the front of everything how will it get very hot?
Do I keep badgering them? I probably would need irrefutable documentation.
Am I wrong?
Do I fix it myself and if so,how? It’s a 400 mile round trip.


Jim

MP,

Thank you so very much! You are absolutely correct. My car is not equipped with wiring or anything. I have a parts car 280sel 4.5. It might just be easier to go the aftermarket route. 

I will keep everyone informed. 

Roland --the aux fan split was in '69 and was about the time they reversed the shifter to forward park. Early 6.3 cars with a/c did not come with aux fan nor is there any wiring for them.

You have two options --pop in an after market fan and wire accordingly and keep your original condenser/drier -or update it to late 6.3. If you chose 2nd option here are some tips:

Find a six cylinder '70/71 108 280 as that car has the compressor mounted on the right side so the condenser is designed to accept a high pressure hose coming from the right (left hand drive car). The second option is a 280 or 300 4.5/33.5 as they will have everything you need --but the high pressure hose to the condenser will have to be routed to the left side (DRIVER'S (LH drive)) because the 4.5 mounts the compressor to the left side of engine --the 6.3 compressor is right side of engine. You need the complete fan assembly, drier, brackets with condenser. Note: cars that came without a aux fan grill were designed with a cutout switch at the left hood hinge area --lift the hood and fan don't run--.

So -from a parts car, steel complete wire harness with fuse box & relay  -there is a temperature switch on the receiver drier --this prevents the fan from running all the time. There is a port on the thermostat housing near the front of the right cylinder head to accept the 212 degree switch so the aux fan will come on when engine gets to 212 degrees regardless whether the a/c is on or not. You need a wire schematic to do this right.

Good Luck!

mpm

Just get the fan from a 70 or 71, they should have the safety grill.  If your car did not come with a fan then you will also need to buy the mounting frame.  You will need to pull the power line from a power source that is controlled by the ignition switch, else your fan will be running all the time, more over that is how it is wired from the factory.  These cars have a tendency to lock heat in the engine compartment, to get around it you can install a time delay switch which runs the fan for a few minutes even when you have switched the motor off, cooling the engine and avoiding the temp. lock.

There should be a seperate AC condenser fan, the old/new difference is on early cars there was no grille to cover the fan but a lockout switch to stop the fan when the hood was opened.
The later cars had a grille over it.
Both were mounted at the front and were exposed when to hood was opened. 

300SEL 6.3 #2723, my first classic Benz 3.5 #8659, my second. 2 to go...

Team 6.3. 

On my 69 300SEL 6.3 there is no condensor/cooling system fan. It appears that they were not on AC equipped vehicles until 1970/71. Has anyone installed the aforementioned fan assembly? If so, what is needed to accomplish the goal? 

Being that I am in Georgia.... thought it would be a good idea as it can be very swampy here in the summer. 


Please advise any and all thoughts/suggestions.