heating problem

[chriSTi]

hello again, this is only my 2nd post so apologies for diving straight in looking for advice but its not nice driving my merc in the cold...
so any help is appreciated...
ok I have no hot or cold air from my vents at the mo... Ive opened up to where the blower motor is and it seems to be working tho not sure if at right RPMs.. so not sure if its the heater valve thats gone or the black resistor thingy on the blower motor.. so can someone tell me the symptoms of each please as they are both pricey parts to take a chance on..... its a w140 1992 S500.. cheers in advance Chris...:wink: oh and windscreen will clear when its on but only with cold air...

 

[television]

The fan motor has 4 ranges of speed I think, the output from the control box is 0-5volts and this feeds the regulator that drives the motor.

If it is the reg pack,,they do come up on Ebay and worth a look

Sorry that you got cold feet when driving your MB

 

[chriSTi]

ok so If I'm gettin no cold or hot air from the vents at all,could it be the control unit?

 

[chriSTi]

hello again folks, happy new year to you all.. just a quick one please ... after sorting the previous problem(duo valve and blower reg) yesterday when I switched the car off the blower kept going, and I've disconnected the battery and gave the reg a few taps to get it working but no joy, so just wondering is it DEFO the regulator or could it be the control unit as the blower speed changes when unit is in off position??? thanx in a advance Chris

 

[television]

I think that water has got into the box and shorted out the reg pack again, with an ohmmeter set to the diode test, the reg pack can be checked and no terminal should short circuit to another I do have a document that you can have for clearing the drains, there is a separate fuse in the box that driver the blower motor

 

[chriSTi]

thanx for reply Malcolm.. I had to disconnect the blower itself just there so it doesn't drain the battery, it seems dry in that area.. I also pulled the few obvious fuses but no joy there... so if its shorted itself I obviously need a new one yes?? and are the ones on EBAY as reliable as a genuine part, that one only lasted a few months??? p.s. the girlfriend is always putting the heat up to full heat straight away from cold would this take an extra toll on the unit??? thanx again

 

[chriSTi]

oh and yes I would appreciate that document if its ok... cheers

 

[television]

I need an Email address please you can PM it

 

[television]

You should have it

 

[chriSTi]

yes I got that ... thanx Malcolm.. much appreciated