Jeremy Bolz

Hello,
hope everyone is having a less confusing day then me.
So ill try to give as much details as possible but hopefully this could be a simple fix. Ever since ive bought my 1995 SL 500 ive had problems with the windows and soft top operation. Recently my issue consists of my driver window staying locked in the up position above the frame of the door (when you open the door the window does not lower). The hard top/ soft top operation works perfectly fine until it gets to the part where it needs to lock into place on the top of the wind shield. So after i did some research within the forms I came to a conclusion that it deals with my controller module and more specifically my relays.

Reference Thread:
https://www.benzworld.org/forums/r12...t-working.html
https://mbworld.org/forums/sl-class-...ble-top-2.html
Relays Thread: https://mbworld.org/forums/sl-class-...ble-top-4.html

So now in my journey I decided to buy the relays off ebay. While waiting until I had time to switch them out I happen to stumble upon a 1999 SL 500 that was being parted out down the street for me. The lowest price for a pulled controller off ebay is around 250$-300$. The guy offered it to me for 100$ so I decided to try it out and just switch the controller module. So now we are in this current position. Ive taken out the original controller and installed the new controller, connected the battery and turned on the car and it worked..... Kinda. So I did a reset on the windows (holding them both down for 5 second then up for 5 seconds until they clicked). Now both my windows work perfectly fine. Now this is where is run into a new issue. The roll bar works perfectly fine but when its in the down position the red warning light on the roll bar switch blinks. The second issue is when I try to unlatch the hardtop with the switch it will not move. When I activate it forward the actuators sound and latch correctly. Other weird feature is as soon as I turn on the car and try to remove the top it starts and the windows start to roll down but it only operates for a second then it pauses and the back latches do not unlatch. So for now I leave the top as is. 3rd confusing issue that I discovered is that after i lock the car from the outside the windows roll down all the way. Im mostly confused by this. So for the time being I just hold the door in the locked position and raise the windows from the outside.

If anyone knows a way for me to basically synchronize everything together that would be very helpful. The only other option I have is to replace the relays in the original control module and hope that fixes my original issue, then just sell the module I have now. Im wondering since its a different year could that be causing issues within the system. Im at a confusing cross way and would appreciate any help. I love to drive this car but I have alot to fix until its back to 100%

bobterry99

I'm surprised you got any functionality at all from the '99 car's controller. You need a controller from a car produced in calendar year 1994 or model-year 1995.

Jeremy Bolz

well thats not good, I guess ill try to change out the relay on the original controller module

bobterry99

Actually, prior to changing the relays I would check to see if they energize when you press the window control switches. You can determine this by listening for a "click" from the controller. If you hear a click consider cleaning the contacts of the existing relays or soldering-in replacements. If you hear no click, then I would read diagnostic codes from socket #21.

Jeremy Bolz

The right side window works fine, The driver window clicks if you roll it up but does not work going down.

bobterry99

With the windows closed and you use the top switch to open/close the top what do the windows do?

Jeremy Bolz

The passenger window will roll down but the driver window will not move at all. The top tries to operate but it stops halfway.

Lee Wireless

Been there, done that. Change both Tyco relays in the RST controller.

Jeremy Bolz

In the process of doing that tomorrow. Ill update it after we switch it out.

Jeremy Bolz

Well we changed both relays but still have the same issue. Driver window does not want to operate.

bobterry99

When you operate the window switch to lower the driver-side window, if there is no audible click, then it would seem your roof controller is faulty.

Jeremy Bolz

I hear a click going up but not down

bobterry99

There are two relays in each "Tyco" package. In parallel with the coil of each relay is a diode used as a "freewheeling" diode. I'd guess the Tyco units incorporate diodes, but they may in fact be on the controller circuit board.

I'd determine where the diodes are. If they are on the circuit board, then I would locate the one for the window down relay and see if it is faulty. If you arrive at the point of doing that and need assistance, then post a close-up photo of the Tycos.

You can google the Tyco part number and find a datasheet that will show whether the diodes exist in the package.