Re: [MBZ] another oddball experience with W123 heat - update

2015-03-24 Thread G. M. Brown via Mercedes
An update for those who may be interested: 1) Installed my acetone + DeOxit cleaned multi-purpose stalk in my '84 300D and all is OK (Yipeee!), and 2) The interior fan problem I was having in my '85 300TD has also been resolved via thoroughly cleaning the pins of the fan speed resistor cage

Re: [MBZ] another oddball experience with W123 heat - update

2015-03-24 Thread wiltonw--- via Mercedes
ATTABOY! Wilton G. M. Brown via Mercedes mercedes@okiebenz.com wrote: An update for those who may be interested: 1) Installed my acetone + DeOxit cleaned multi-purpose stalk in my '84 300D and all is OK (Yipeee!), and 2) The interior fan problem I was having in my '85 300TD has also

Re: [MBZ] another oddball experience with W123 heat - update

2015-03-13 Thread Andrew Strasfogel via Mercedes
I'm going to check the coolant level this weekend to see if it went down again. I had good heat today, with temps in the 30s and 40s (DC area). If the coolant level is still normal then I guess I don't need a monovalve after all. On Fri, Mar 13, 2015 at 6:50 PM, Jon Agne via Mercedes

Re: [MBZ] another oddball experience with W123 heat - update

2015-03-13 Thread Jon Agne via Mercedes
I’ll say it again. Chinese monovalves are crap. If your monovalve has a minuscule tear in the rubber diaphragm, it’ll work great for a awhile, and the return to it’s unpredictable and errant ways. IIRC, you also had an issue with low coolant, so hopefully, your present (old) monovalve is

Re: [MBZ] another oddball experience with W123 heat

2015-03-12 Thread Jim Cathey via Mercedes
The signal to the monovalve is 12V PWM, and a slow rate. 1 second on to several seconds off, for example. I have a red LED mounted behind the defroster PB on the SEL, so I can see when it's trying to heat versus not doing it. I clearly have a monovalve problem there, but so far its its inability

[MBZ] another oddball experience with W123 heat - update

2015-03-12 Thread G. M. Brown via Mercedes
Guys, I changed the new mono valve insert, which I had obtained from the PartsGeek, back to the one I had in there previously where one could not regulate the temperature via the PBU thumbwheel . . . it would be max heat at the MAX position or almost no heat at any other temp setting. The old

Re: [MBZ] another oddball experience with W123 heat

2015-03-12 Thread Jon Agne via Mercedes
If the monovalve is OK, and it passes the diagnostic test, then it’s probably one to both of these two things: 1. Your temp sensor is bad (under that little grill on the dash, the grill is actually part of it) and/or 2. the tube that supplies the suction to carry the air past the sensor has

Re: [MBZ] another oddball experience with W123 heat

2015-03-12 Thread archer75--- via Mercedes
AFAIK When you switch to max you are stopping all current flowing to the valve. If the heat stops after you switch to any setting other than max, it sounds like the coil might be shorted out. I would check the voltage across the leads going to the valve while someone moves the control back and

[MBZ] another oddball experience with W123 heat

2015-03-11 Thread G. M. Brown via Mercedes
Since both my '84 300D '85 300TD have trouble maintaining heat as chosen via the thumbwheel on the left of the PBU and I've been through (including resoldering) the troubleshooting guide numerous times for both units and not found a definitive problem. To explain about the problem of not

Re: [MBZ] another oddball experience with W123 heat

2015-03-11 Thread Andrew Strasfogel via Mercedes
It could be the monovalve assembly itself. On Wed, Mar 11, 2015 at 11:28 PM, Curly McLain via Mercedes mercedes@okiebenz.com wrote: Since both my '84 300D '85 300TD have trouble maintaining heat as chosen via the thumbwheel on the left of the PBU and I've been through (including

Re: [MBZ] another oddball experience with W123 heat

2015-03-11 Thread Peter Frederick via Mercedes
Check to see if the valve moves when you apply voltage to the coil, and that you get full heat if you unplug the valve. The coils do fail, especially if the valve leaks coolant into the coil housing, which can happen when the rubber splits. If the valve is stuck shut by a corroded coil,

Re: [MBZ] another oddball experience with W123 heat

2015-03-11 Thread Curly McLain via Mercedes
Since both my '84 300D '85 300TD have trouble maintaining heat as chosen via the thumbwheel on the left of the PBU and I've been through (including resoldering) the troubleshooting guide numerous times for both units and not found a definitive problem. To explain about the problem of not