Hello,

My 89 300E has windows that randomly failed on me. They were working earlier in the week, but now they do not go down, nor do I hear noises when I press up. My first suspicion were the fuses (G & H) so I replaced them, but they still don't work.

Is there another common location that all 4 window motors go through to check? No window buttons on center console work (mirror adjust , fader), rear window switches on door panel do not work either (tried child safety lock in both switch positions). Thanks in advanced.

A new interesting issue which might be related. I notice my power memory seats do not work either. They only work when the door is open, but if the door is closed, the seats do not move even with key on position.

Windows still do not work with doors open or closed.

Which windows, all, back front?

__________________
1987 300TD 309, xxx 2.8.2014 10,000 mile OCI


Be careful of the toes you step on today, as they may be connected to the ass you have to kiss tomorrow. anonymous

“Be who you are and say what you feel, because those who mind don’t matter, and those who matter won’t mind.” Dr. Seuss

All windows do not work currently. Rear windows do not even work with their own switch on the rear door panels with child safety switch in both positions. It's as if all 4 motors died at the same time, but I highly doubt this happened.

Convenience control unit could be bad. I think it is in the back of the fuse box. Depending on the year there might be one that control the seats and the windows. I think the newer 124s had 2 relays.

__________________
1987 300TD 309, xxx 2.8.2014 10,000 mile OCI


Be careful of the toes you step on today, as they may be connected to the ass you have to kiss tomorrow. anonymous

“Be who you are and say what you feel, because those who mind don’t matter, and those who matter won’t mind.” Dr. Seuss

Never heard of this part before. Does an 89 W124 have this?

See if post #5 of this thread helps.

__________________
1987 300TD 309, xxx 2.8.2014 10,000 mile OCI


Be careful of the toes you step on today, as they may be connected to the ass you have to kiss tomorrow. anonymous

“Be who you are and say what you feel, because those who mind don’t matter, and those who matter won’t mind.” Dr. Seuss

Thanks for the information. I ended up replacing relay F from this diagram:



This is what F looks like:



Replacing this brought control back to windows and power seats.

So this problem came back after a couple of weeks and has been repeating itself. I keep replacing the relay with a different unit and the windows/seats start working again, but fail after a while.

Also to note, the power seats have completely failed, they do not even operate when the door is open. Windshield wiper does not operate as well.

Is there something else to check that might be causing this? The fuses are fine, they don't blow out. I've tried moving the relay around while holding the window controls up to find a loose terminal, but found nothing.

Is there a way to test the relay itself to find out if the relays are going bad or something else in the circuit is going bad?

I took the relays that "failed" and they seem to work correctly when tested on the bench with 12V and a continuity tester.

Is there a wiring diagram available for this part of the car?

I believe I have found the diagram:



Does anyone know which terminals are which on K24? The relay itself only has 5 connections but the diagram shows 6? I can see that it connects to E and something else on the fuse box (F1)

I looked at the diagram on the fuse box label and 86 was listed on fuse 2. This looks to be the unreadable print on the diagram for F1 connecting to the diode on K24. I replace fuse 2 (16A red fuse) and the windows seem to be working again.

Hi I am so glad I found this forum, I am having the exact same problem with my car all four of the windows work intermittently and the seats will only work if I open the door and the windshield wiper does not work. What part did you say would fix this.