Please help me kick my servo to the moon

[Harv]

I'm ready to unleash the power of a 1,000 hells on my servo. It looks like the damn thing is leaking (it has been for years) and I can't get it to spit out any heat on the DEF setting at all. Earlier this fall it would work randomly but now I have nothing. When I say randomly, I mean I would start the car and drive for 30 minutes with full heat, shut off the car to run in the store, come back out and turn it back on only to be greeted with the vents shooting ice cubes. It is not the aux waterpump, it seems like the servo isn't pumping coolant.

I'm willing the rip the entire thing out and replace it with copper piping since I already have a shutoff valve installed. (See pic 2 under the air filter housing). Problem is, I can't figure out what needs to be connected with what. Does anyone have pointers about what hose needs to connect to what hose when removing the servo? All the help would help me from freezing to death on my drive home from work.

[daantjie]

The ACC headache strikes again !  Well if you are willing to go midieval on the thing why not open up the top cover and see if you can get the gear mechanism to park?  You should hear it whirring when you turn the ignition off, normally they run for about 5 seconds.  Soak the gears in some PB Blaster or electrical contact cleaner coupled with some compressed air blasts just for kicks and see if you maybe free things up?  There is one pipe into the cab and one pipe out, so if you can bridge the right pipes and install a tap then as you said you can at least have heat on and off.  Check out the EPC, you might be able to tell where to pick up the hot water from the engine, I think it is on the passenger side but not 100%.  Squiggle Dog is the expert on this sucker BTW

[daantjie]

This post might save you from the bottle

https://forum.w116.org/mechanicals/i-begin-tackling-the-acc/30/

[Diesel 617]

I see I am not the only one with ACC woes this winter. I borrowed these instructions from the mercedesfix guide

Looking at the servo. The ports where the Aux. Water pump connects into is the shut off valve side, goes straight across. bridge those hoses (if you want put a shut off valve here for summer time) Then bridge the hoses to the left of the water pump those are the return lines. Leave the line the connects to the bottom of the Aux pump alone.

I just received my Mercedesfix ACC system and report back (it is beautiful). Either Thursday 36F or Saturday 51F will be install day (and a block heater)

MercedesFix thread here (327$ out the door code on the 2nd page) https://forum.w116.org/mechanicals/1st-gen-mercedes-accii-climate-control-servo-less-expensive-replacement-option/

[UTn_boy]

Andrew, did you check your amplifier, and did you check the fuse? 

[Harv]

Andrew, did you check your amplifier, and did you check the fuse?

I was under the impression that the inline fuse in the fuse box was only to ''park'' the servo after it was turned off. And I thought the amp was working because of the intermittent working of the servo. If the amp was dead, I wouldn't get anything at all.

You can see that someone did install a shutoff hardline under the airbox already in the second photo. I can flip that lever and it'll totally kill all heat. So adding a second valve wouldn't be needed. 

[Diesel 617]

Oh yeah, I see that now. Well in that case your set to just remove the servo, plug the vac lines, tape up the electrical connectors for corrosion prevention and put two pieces of pipe in between the hoses.(straight across)

[Squiggle Dog]

Squiggle Dog is the expert on this sucker BTW

Very true! My expert advice is to rip it out and drop-kick it across the yard.

[daantjie]

Squiggle Dog is the expert on this sucker BTW

Very true! My expert advice is to rip it out and drop-kick it across the yard.

Ha-ha too funny !

[Harv]

Oh yeah, I see that now. Well in that case your set to just remove the servo, plug the vac lines, tape up the electrical connectors for corrosion prevention and put two pieces of pipe in between the hoses.(straight across)

This seems like the best option since the AC has never worked. What other purpose does the servo have then if I can just bridge the lines.

I'm guessing copper or brass pipe is the best material for this?

[UTn_boy]

Andrew, did you check your amplifier, and did you check the fuse?

I was under the impression that the inline fuse in the fuse box was only to ''park'' the servo after it was turned off. And I thought the amp was working because of the intermittent working of the servo. If the amp was dead, I wouldn't get anything at all.

You can see that someone did install a shutoff hardline under the airbox already in the second photo. I can flip that lever and it'll totally kill all heat. So adding a second valve wouldn't be needed.

Ok,  I was only trying to help.