Hello!

Overall, my ACC's working properly. However, a couple of times now, I've noticed this. When in "EC" mode, occasionally, it gets stuck on full heat, regardless of where the temp control wheel is (it does respond to the fan setting, but if on AUTO will go to high speed). If I turn the unit off or turn it to AC, things go back to normal, and I can go back to EC mode and everything will work properly.

Again, this has only happened once or twice. Should I be concerned? It's a minor annoyance, but if it isn't an indication of something being wrong, I don't have a problem with it.

Thanks in advance!

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2001 VW Jetta TDI, 5 speed, daily driver
1991 Ford F-350, work in progress
1984 Ford F-250 4x4, 6.9l turbo diesel, 5 speed manual
Previous oilburners: 1980 IH Scout, 1984 E-350, 1985 M-B 300D, 1979 M-B 300SD, 1983 M-B 300D
Spark-free since 1999

I would suspect either a fuse or more likely the push-button unit is starting to go (cracked electrical joint or bad capacitor). Full heat defrost with full fan is the default mode for the unit. There might be a cracked solder joint in the unit which will only get worse with time. If you haven't already, replace the fuse ( nice and cheap), then if it persists, take apart the ACC push-button unit and resolder and/or replace any electrolytic capacitors. If that doesn't fix it, you can get a replacement ACC pushbutton for about $200.

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D. Blake
86 300SDL 340K (for sale)
83 300SD 205K (gone)
06 Chevy K3500 LBZ CCLB 50K
94 Chevy K2500 6.5L TD 250K (gone)

It's that new fan you put up front. It has upset the electrical balance of the car!

(kidding)

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Rick Miley
2014 Tesla Model S
2018 Tesla Model 3
2017 Nissan LEAF
Former MB: 99 E300, 86 190E 2.3, 87 300E, 80 240D, 82 204D Euro
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