Heater Fuse
 

Where is the heater blower motor fuse located, 1993 M-B 300D 2.5 Turbo with automatic heater / AC?

Thanks, Lgriffi

Should be over near the drivers side strut tower ..in a little box,
F-15 fuse link.

Thanks Art
Found the fuse, it is OK, have voltage both sides, still no blower.
Lgriffi

Jumper the fuse to make sure ...they open under load, so they can read good w/meter, but bad with blower draw....

If OK , then check the 3 wire plug on the firewall behind booster. That is blower/regulator feed;
!2 across red/blk... variable 2-9v across yl/blk

Thanks Art, I tested the fuse, OK, I went ahead and installed a new fuse, still no heater blower and winter is setting in.
Lgriffi

Then do the next test I posted...

Thanks Art, I will do the second test latter today.
Thanks again for your help.
Lgriffi

OK
Your main concern on that test is that the Control Panel is giving you the variable V at that yl wire b/c that is the blower speed trigger signal for the blower regulator..if you have no trigger sig to the regulator, you have no blower.
And no trigger is upsteam from that connector, not down-stream [ meaning down at the blower/regulator.]
You must meet those two voltage checks before going down into the blower/reg end.
If you have no V sig from CP, then it could be as simple as a bad feed fuse for CP. [ fuse #7 on your chassis]
If both test are YES at that 3 wire plug, then you have a problem down at the blower/reguator compartment.
In that case , you would jumper a wire from the BLU wire to ground..if that gets you High Blower , you have a bad regulator... see many guys change the reg only to find out later that the reg was fine and was simply not getting trigger V from CP... a costly mis-diagnosis.......

Hi Art
Have preformed the second test, have 12.9 V across the black and red terminals and 1.9 V across the black and yellow terminals. I guess this indicates a problem with the blower / regulator. Where will I find the blower regulator compartment? Is it behind the wiper assy.?
Regards, Lgriffi

Put the CP on defrost to see if you can get that trigger V up some..
B/R and down under wiper assem...

Hi Art
Voltage between black and yellow wire with push buttons in defrost position is 2,7 V.
Thanks for the help.
Lgriffi

That means ya gotta go diggin...

When you get in there , ground the blu wire and also try to turn the fan by hand to see if it is bound up...........ATF works sometimes.

Hi Art
Thanks for sharing your knowledge and information with me. I will go diggin latter in the week.
Thanks again. Lgriffi

There is a DIY, step by step, w/pics on the Forum
Use the Resources section on top of the page and you will find Blower Replace..

ive got the same goin on my 1990 300e are these bolth 124s? because i need to do the same tests thanks