W124 electrical issue - PeachParts Mercedes-Benz Forum

jake12tech · #1 01-02-2018, 09:24 PM

It's one problem after another with this POS w124.

So I took apart the headliner and removed that panel that the rear view and courtesy lights clip into. I went to go plug back in the tempetature sensor, sunroof switch snd courtesty lights and it blew fuse 5,6,9. Then the instrument cluster started making a weird buzzing noise. The fuses that blew were for the cluster. Lost turn signals and hazards as well as the oil pressure, fuel and coolant gauge.

Is there a certain orientation this is supposed to be plugged in? I see there's numbers on the connectors but they don't match the numbers that light and sunroof switch.

vstech · #2 01-02-2018, 09:39 PM

I am certain the orientation is needing correct orientation. Every mb socket I have seen has a plastic alignment pin...

jake12tech · #3 01-02-2018, 10:02 PM

Quote:

Originally Posted by vstech

I am certain the orientation is needing correct orientation. Every mb socket I have seen has a plastic alignment pin...

What's weird is I used that alignment pin And it just started blowing fuses which tells me something is shorted but I have next to no idea how. I've never had so many issues until I got this w124. Everything on it has been messed with electrically at some point. The hack job on the radio harness is a sight to see.

torsionbar · #4 01-02-2018, 11:15 PM

Quote:

Originally Posted by jake12tech

The hack job on the radio harness is a sight to see.

The sad thing is it was probably a professional installation. I've seen some real garbage wiring jobs come out of local car stereo shops.

dieselbenz1 · #5 01-03-2018, 12:09 AM

Are you working on electrical that is still energized? Even just unplugging and plugging in multi pin connectors can can cause problems as not all pins will be electrically connected at the same time.

Bengoshi2000 · #6 01-03-2018, 07:15 AM

Please tell us you disconnected the battery prior to surgery...

jake12tech · #7 01-03-2018, 08:07 AM

Quote:

Originally Posted by Bengoshi2000

Please tell us you disconnected the battery prior to surgery...

Yes, I learned the less the hard way in the past without doing that

jake12tech · #8 01-03-2018, 08:08 AM

Quote:

Originally Posted by dieselbenz1

Are you working on electrical that is still energized? Even just unplugging and plugging in multi pin connectors can can cause problems as not all pins will be electrically connected at the same time.

No everything is plugged in the correct orientation. I used the alignment pins plug it in a bam goes 3 fuses blown. I've been working on these w124s long enough that this to me isn't normal and something must've got shorted somewhere

spock505 · #9 01-03-2018, 09:20 AM

I have been trying to track down a wiring fault from the oil level sender to cluster, no joy despite most of the wiring being replaced along with sender itself.

Fuel gauge caught me out the other day moving slowly down, should have known better as it ran out of fuel reversing off drive.

My approach now is to live with some of these 'endearing..ahhmmm..' foibles, unless of course it's a customers car.

Yours has multiple faults which may get worse, probably needs fault finding to at least eliminate some of the issues, sorry I couldn't be of more help - empathy support only : )

funola · #10 01-03-2018, 09:51 AM

If this is the same car that you left the key on while working on the cluster and smoked it, you need to find and fix that damage first! It will not fix itself so stop throwing money awat and burn up more clusters and fuses. All you need is a wiring diagram and a volt/ohm meter.

jake12tech · #11 01-03-2018, 09:59 AM

Quote:

Originally Posted by funola

If this is the same car that you left the key on while working on the cluster and smoked it, you need to find and fix that damage first! It will not fix itself so stop throwing money awat and burn up more clusters and fuses. All you need is a wiring diagram and a volt/ohm meter.

I was able to resolve that issue. Thanks funola.