HELP Another 300SL Roof Problem (FOUND SOME CODES)

[pdevlin]

Hi i have reacently bought a 300SL 24v 1990 G reg, when i got the car the roof was in good working order. Now the roof isn't working at all. one night i decided to put the hard top on. I placed on the hard top and it wouldnt go down in one corner, the red roof operation switch was flashing a pinging everytime we drove the car. We decided to leave the car parked up and have another look the morning after, we then had the roof up down on and off for several times not realising that your not meant to operate the roof more than ten times we then heard a loud grinding sound and stopped everything. we later realised that one of the switches had fallen of on the rear right roof clip. We then manually put the hard top on and it has been into Mercedes Dealership garages several times but all they seem to want to do is change every component of the roof system equaling to the value of £3000. I have tried the code Diagnostic check (thanks to bobterry99) and the codes that i got out of it were 6, 10, 11, and 25.

Any help at all would be gratefully appreciated

[bobterry99]

Codes 6. 10, and 11 indicate the top is not latched properly at the left front and rear and the right front corners. Code 25 means that the controller is receiving inputs which contradict each other...Does the soft top go up and down still or is that having problems as well?

[pdevlin]

Hi ,thanks bobterry for replying (I am in a sorry situation) the softop roof is not working at all. When the hardtop is removed and we operate the roof, the softtop cover (housing) tries to lift to open but just clicks shut again, as if it trying it's best and just gives in. Even when the hardtop is removed the red light is still on and alarm sounds when driven. Also the diagnostic check is giving code 20 even when roof is off. Gratefull for any further help

thanks Peter Devlin

[bobterry99]

I suggest checking operation of all the switches in the system, Peter. When a switch closes to signal the controller, it does so by completing a circuit from the controller to chassis ground. All of the switches are wired to the "Y" connector of the soft top controller. You'll need a basic multimeter or other device for measuring continuity between the inputs and ground.

To access, open the storage compartment behind the passenger seat. Remove the plastic cover that protects the soft top controller by loosening three 10mm plastic nuts. The "Y" connector is the long black one (there are two others as well -- the "X" and "Z" connectors). Now remove the two 10mm nuts that are securing the controller and lift it off of its mounting studs. Now you should be able to easily separate the "X" connector from the controller.

Looking at the connector you will see two rows of sockets numbered sequentially. Nearly all of these are inputs from the switches, though some are not used. You proceed by putting the top in "Position 1" and checking all the switches and then repeating the same for "Position 2". The info below shows which inputs should be open and which should be closed for each position. Have the ignition off while you perform your checks. Note that you only need to check 17 inputs.

Position 1 (Top closed, windows up, roll bar up)
Open: 10, 22, 27, 29, 30, 31
Closed: 16, 17, 18, 19, 20, 21, 23, 24, 25, 26, 28

Position 2 (Top open but storage compartment cover open, windows and roll bar down)
Open: 16, 17, 18, 19, 20, 21, 23, 24, 25, 26, 28
Closed: 10, 22, 27, 29, 30, 31

[pdevlin]

hi thanks bobterry99 thats great i will try these checks and get back to you with the outcomes. very much appreciated thank you peter

[Gilly]

Quite often the problem is one of the rear latches in need of replacement or at least resetting. If you remove the hard top and check the rear latches, you may likely find one of the latches in in the up position (ready to receive the hard top) and the other will be down as though it has already captured the hard top and pulled it down.

Gilly