texterted

Anyone have a clue where this is located?

My rear booster blower has taken on a life of its own! It blows air when switched off, I've had to pull the fuse to disable it.

Many thanks.

Maj. Dundee

What is the fuse # and in what location?

texterted

Drivers Door Pillar (Cabin Location)
Fuse - f10
Clamping Device - 30,
Cable I.D.- 1.0 RD 10
Function - Booster Blower electronic controller (N29/2), Rating 10 amp.

Thanks MD

Maj. Dundee

The N29/2 is located at the rear of the center console. It is controlled by the AAC Control Module.

Key out of ign. and with a test light or DVOM, check both contacts at fuse #10 for 12v; also check fuse #12 for 12v.

. Post back with results.

Maj. Dundee

Please UPDATE YOUR PROFILE IN USER CP to include the year of your ML.

texterted

I shall investigate, thanks MD.

texterted

Well, the fuses both check out ok and both have power, ignition on for #12.

The booster blower controller, sits on top of the unit and is accessed by removing the centre cup holders. It's a solid state unit with an integral heat sink.

There's not much I could do except check the wiring, as best I could. I may price up a replacement, although, I don't sit in the back so I may leave it if it's expensive!

Thanks again for your help MD.

texterted

Thinking about it some more, both of those fuses shouldn't have power with the ignition off. Seems I have a short somewhere?

Maj. Dundee

Correct. Fuses 10-15 should be on circuit 30, hot at all times.

flybd5

Did something get spilled in there? This isn't hard core digital technology, it might just be corrosion from a spill that's shorting contacts in a connector or something like that.

texterted

Aye, that's what I was hoping for, a crusty connector from a spilled coke. I didn't even find any lost french fries!

flybd5

Ah. No kids. Got it.

texterted

I got the car used, so you never know what's happened.

I've had the radio and glove box off today, to check the wiring looms. I can't find anything amiss.

I was wondering if a relay controls this booster blower? I didn't get a wiring diagram with the vehicle. Anyone got an idea where to get a vehicle specific one?

flybd5

While Maj Dundee answers that one, this is a bit out there, but you might want to try disconnecting the battery, then reconnecting it to see if that resets things. Note you will need to reset windows and others things after that as per the owner's manual.

texterted

Aye, I did that already, thanks.

The thing works correctly, all the functions are as normal. It just continues to run when you remove the key and lock up. Weird!

Fingers crossed MD can find something in his vast libraries!

Maj. Dundee

Post your full vin#.

Do you have a scanner? Either way, the codes must be read in the AAC Cont. Mod.

texterted

I'll pm you my VIN.

Yes, I've found a code....

9607 Booster blower : There is a short circuit to ground or the line for the readback voltage has an open circuit. DTC Status : Current and stored.

Thanks MD.

flybd5

1. VINs are not like bank account numbers. If you only send them in PMs only one person can help. Far as I know no one does that around here.
2. That is a generic code, not a Mercedes code. You need to read the computer with Star Diagnostics system or a scanner that understands Mercedes codes and can query all subsystems, .

Maj. Dundee

The code 9607 concerns the Booster Blower Motor and not the Booster Controller, N29/2.

Do you still have access to the N29/2?

texterted

It's pretty easy to get to, it sits on top of the motor under the cup holders.

Maj. Dundee

Look at the diag.. M2/1 is the rear blower motor. Test the two wires, with the ign. off and with the eng. running and A/C selected.

texterted

Got this issue solved.... with a new N29/2 booster blower controller.

I got one, made from chinesium, from a seller on Amazon, cost was about $25 posted. I was expecting it to come on a slow boat but I got it within a week.

It seems that quite a few merc's have this resistor. Which is all that it is, a PWM Generator on the earth to the motor.

beanieBenz

Is there a part number for the booster blower controller? I can't find it on Amazon or eBay.