intermittent W124 blower fan
 

95-F; 83% humidity.

No acceleration, just a nice smooth drive.

HVAC Blower fan just stops working.

Turn-off HVAC by pressing the ZERO (0)/off button for 1-minute.

HVAC blower fan comes back on.

What's the proper diagnostic ?

FWIW, the fan will run for a 45-minute commute, but just die intermittently after a 1-2 hour heatsoak.

:-( neil
1988 300TE

Check the tensioner and belt. If it slips the system will cutout the climate control.

Good luck,

I don't know the history of your particular car, but as most owners of the 124 (at least the ones in the '80s which are in their mid to late teens now) know that there is a blower fan problem witch literally destroys the fuse holder. There is a variety of ways to correct the problem, one of which is to bypass the fuse and install a circuit breaker, along with a new blower motor. This is the route I took over a year ago. When the weather here in NM gets very warm like during the past month, the fan run on high speed with the AC keeps up for about what you said, 45 minutes to an hour, then the circuit breaker starts cutting in and out. On low speed it isn't an issue. My guess is that you have a circuit breaker installed rather than a fuse.

Plink49, how much did the labor cost to have the new blower installed.

Vincec....the labor cost to replace the blower motor (with cages) was $165 which unless you really enjoy doing the work, is money well spent. I think it amounted to an R&R of 2.2 hrs.

Plink49, thank you ...!!

I don't have a circuit-breaker replacing the 30Amp strip-fuse.

However, I did clean the blower-fan connector behind the yellow vacuum check-valves on the driver's side, and I took apart the push-button controller to see if thee were any cold solder joints.

I re-soldered each pin just to make sure.

We shall see . . .

:-) neil

What I have noticed is that my blower works in the mornings, (becos its cooler? ) and not during the rest of the day when it gets hot and when I REALLY need the air conditioning. Also, even when my blower is not working, I can feel the very cold airconditioned air seeping thru the vents, which points to a blower failure or the blower relay. My mechanic could not take me in today becos he is busy. Maybe tomorrow he tells me....

Ok, so I went to Fletcher Jones, a large local MB dealership to buy a new 30 amp metal strip fuse and aslo check their prices and check their return policy on a few potential culprits of my blower failure; a new ignition switch, a new fan blower, and a new a/c relay.
The strip fuse that 'looked ' perfectly fine ( not only to me but to a few more knowledgeable fellow MB enthusiasts at the Encinitas MB GTG, and again in my garage when I rechecked it) was the culprit. Replacing it got the a/c working right up............!!!!!!
Funny thing is that when I drove up, a few techs and dealer employees at Fletcher Jones ( they were probably getting off work, +/- 6pm) started to mill around my car, checking it out and those that knew started telling those unaware what they knew about the car. I was at that point a very proud owner plus already very happy that it was a blown fuse and nothing else. I left Fletcher Jones with a great impression cos on top of the free strip fuse and install, I also got a 3rd brake light bulb, also on the house. Not that these were expensive or anything, but these were good gestures
Thanks all for the advice, for getting me started as to where I should be looking.........!!!
__________________

Finally you are getting the recognition you've always deserved.
:D

Paul, yes, need to wallow in it and savor, for it might be a long time be4 it occurs again. BTW, going to make it for the Carlsbad meet this Thursday?