PeachParts Mercedes-Benz Forum - View Single Post

cphilip · #20 12-30-2008, 08:38 PM

Comment and provide any details you might have to accomplish this procedure you were recommending way back in 1999 Arthur... If you will...

For those interested in the manual over-ride cabin sw, ..the main reason for using the low fan circuit vs high fan is b/c you just have to hook your toggle ACROSS the high side pressure sw to make it work. This is as simple as it gets and there are 2 distinct advantages to using this point in that circuit for the switch ...the first being that you are still using the entire factory circuit
for fan activation [ minus the high side sw], meaning you still have a relay circuit and the protection of both the relays coil side fuse and the fans load side fuse...they are already there , plus the R15 Dropping resistor .... so this jumper/toggle uses the stuff that is already there ......you just add the switch....... The other nice about this is that when you are NOT using the manual switch, your fan circuit is right back to STOCK FACTORY confiquration..no change at all...that is why I refer to it as a low fan system OVER-RIDE vs just a manual low fan circuit. You are simply over-riding the pressure switch b/c you are in parrallel with it. The rest of the circuit could care less....

This is of great interest too. Particularly in conjunction with the resistor to have High speed cut in a tad early too.