1992 300D Climate control issues
 

None of the posts are exactly describing my problem.

I have no blower (just hot air when driving)....no compressor engage...no aux fan
I can jumper pressure switch on receiver drier and engage compressor
I had local electronic shop re-solder climate control
All fuses seem good
I just dont know where to start...

If jumping the pressure switch turns on the compressor, it a good bet the system is low on refrigerant.

If the blower isn't working then you must evaluate the blower regulator circuit. There are multiple threads in the archives showing simple techniques for this.

Strip Fuse..
 

you said you have no blower motor functions ?? from clim control?

my two 300 2.5's have a strip fuse located in a black plastic compartment

its like a piece of aluminum sorta like a fuseable link that can blow and result in now blower...

just a thought ,, its located right near the drivers side strut..

there are two eyelets the connect to the fuse and it goes dir to the blower on the clim control unit, if fuse is shot you wont get ANY blower function

hope it helps.. :rolleyes2

Attached
 

jpg of the fuse can be found here

http://catalog.eautopartscatalog.com/buymb/wizard.jsp?partner=buymb&clientid=buymbparts&baseurl=http://www.***************/&cookieid=1GX13ALEP1HK11A6JF&year=1990&make=MB&model=300-DT-003&category=All&part=Strip+Fuse

blower motor fuse has power on both sides....
what else could it be...
I'll ck the blower regulator next....any hints on how I start that

blower motor
 

wayne I had to replace my blower motor on my 1992..

let me ask you this... is your tachometer working?

the tach sends a reading to the KILMA via a sending unit..

i also had to replace my altenator and over voltage protector and my tach sending unit/ sensor //

i didnt do the work myself... the ovp went thus burned out the altenator ..
so i first replaced the volt regulator.. then 2 days later the voltage regulator went,
my suggestion is to take the blower motor out and see if you can get it to run via hokking it up thru the battery..

hope this helps

Ok...thanks for all the help so far.....

The blower motor is bad!
Now how di I check the regulator?
Is there a chance that the regulator is bad and thats what caused the blower to fail?

If the blower went bad shoul it have blown the fuse?



Wayne

new blower motor installed......
But still no air blowing......

Do I assume its the regulator....all fuses are good

tach sending unit - more info pls McDiesel
 

Mc Diesel

I have a tacho that is mal functioning and zero cold air from A/C. I also have bad running when engine cold and an intermittent cruise control for good measure. I've just spent the last few days investigating the OVP reading stuff on this forum however it checked out perfectly so I'm back to square 1.

Can you explain more about this tach sending unit and its relationship to the KLIMA unit. Where would I start my diagnosis?
:confused:
thanks
Keith
1995 E300 Diesel

latest update....

-blower motor removed....lots of dust from brushes, and armature really worn down...I grounded blue wire to fan motor body and still no fan. If I supply power to fan directly from the battery it works. Given the condition of the armature I might change it out any way.

-I had the new fan installed and thought before I had it all together I would test it. I made sure all connections were made and turned on economy setting setting and fan on high...still no fan. While I was trouble shooting I heard a relay clinking in the fuse box area closest to the firewall.

-Im afraid to change blower regulator if the relay is bad there is too much money involved

Please help!

circuit diagram?
 

I find it really helpful to get the full circuit diagram off the CD and spend an hour or two with a coffee following it through. Helps to stand back from the problem and isolate possible suspect relays etc. Just managed to resolve an a/c control problem in this way so maybe it helps you also.

Keith

thanks for everyones suggestions !

I was fortunate enough to find a Climate Control unit that I could borrow and that was the problem...
Now I just need a good deal on a CCU