Unwired Tools AccII Upgrade kit

[thorsen]

The climate servo in my 1980 280SE stuck in the open position and killed the battery - there is a constant .5 amp drain when the servo is plugged in, even with the key off. It looks like it's time to upgrade to the Unwired Tools kit. if you have one - what are your thoughts about it?

[alabbasi]

I've known a couple of people who installed them but they ran into issues which required some efforts to put right. I found a replacement aluminum housed acc unit when my first 6.9 experienced the same problem and installed it. I bought it used on eBay for $100 and it worked perfectly.

[thorsen]

If I could fine something for $100 I'd do that too! Unfortunately all the rebuilt servos I see are in the $350 - $400 range. Seeing as how I'm not sure if the servo cooked the amp I could see myself rapidly approaching a point where I would say "I should have just bought the UT kit".

Thanks for the thoughts.

[thorsen]

The UT kit came in today and 30 minutes later everything was installed. Of course I had a week of down time to prep and replaced heater hoses, cleaned underneath the old servo, etc. The kit seems well designed and I'm happy enough with it.

[diametricalbenz]

Do keep us posted on its performance. I too am considering the conversion when my servo eventually decides to throw in the towel if I don't find an aluminum housing servo before then.

[alabbasi]

That's good news, the people that i spoke with struggled so I suspect that UT made some improvements or your more technical. I do know that they added LED test functionality in later versions that was not available in the earlier styles.

[Benzman53]

I installed and Unwired unit on my 1980 300SD 2 years ago. Initial installation did not work and I was forced to use a manual heat valve until spring. Surfing their website, I found a later revision of their installation manual which showed an entirely different schematic for hook-up. VOILA! It began working correctly and has not malfunctioned since.

[thorsen]

The only shortcoming of the system I see is that the heater valve needs vacuum to stay closed. If you are out running errands and shut the car off, as the vacuum bleeds down the hot water valve opens - opening the heater core to hot water. This is not an issue in the winter but during the summer it's an extra load the AC has to try to cool off.

My solution was to put a 1/4 turn valve after the hot water valve to positively close off the heater core during the summer.

Other than that single issue (which is actually a safety factor) I am still happy with the kit.

[Emmerich]

You can pull the inline fuse in the fuse box to kill the servo. I did that before i got the UT kit. Mine had vacuum issues at first, not sealing properly on the plastic manifold where the little lines plug in. They have updated the kit and made it better I hear.