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

[pdevlin]

thanks for the reply, wer'e in the process of checking the car today, while wer'e there we will check the latches are in the correct posistion. wel will post back later today, thanks once again peter & son

[pdevlin]

hi bobterry99 i have followed the instructions as posted, looking at the connector there are no numbers. There are 18 sockets on the top row and 17 sockets on the bottom row.
In position 1 we had a reading on the 13th socket along on the top row of 18 sockets.
In position 2 we had a reading on the 13th and the 15th socket also on the top row of sockets. we had no readings from any other sockets.
I assume we have done this correctly looking forward to your reply.

[bobterry99]

I should have mentioned that the actual numbers appear on the male side of the Y-connector, Peter. Looking at it the female end the way you are -- that is, with the row of 18 being on top -- they number 1 to 18 left-to-right across the top and 19 to 35 from left-to-right across the bottom.

Regarding the measurements, were you measuring resistance between the sockets on the female connector and a good chassis ground? Because according to what you reported, your controller is receiving no signals from any switches! And remember, you are only concerned with sockets 10 and 16-31.

[pdevlin]

hi bobterry99, we measured the output from the female end (Y connector)with a good chassie ground, top row reading left to right (18 pins).Doesn't sound so good no other signals received??? we can repeat the process if needed. thanks peter

[bobterry99]

Peter, I suggest checking one of the input circuits in detail. With the soft top closed and the rear bow raised, locate the switch pictured below. Remove the electrical connector to the switch. Verify that one of the two wires on the connector is wired to ground and the other is wired to socket #27 on the Y-connector. Verify the operation of the switch as follows: when you push down on the plunger the contacts close, and when you release the plunger it opens.

[Gilly]

Codes 6. 10, and 11 indicate the top is not latched properly at the left front and rear and the right front corners

I am still curious, since there seemed to be a fault in the right rear latch, is the right rear latch pawl (the part that the hard top tab latches on to) in the "up" position or "down"? Compare the appearance to the left rear. Most of the time that I have seen these become out-of-sequence it seems like it's the right rear. Maybe the codes are wrong, and instead of all of the latches except the right rear being incorrect, maybe just the right rear is incorrect. Can you post a picture of both of the rear latches from viewed on top?
Gilly

[pdevlin]

hi guys thanks for reply very much appreciated. it will be weekend before we can look at the car as it gets very dark early over here. will post back asap thanks peter

[poloplayer]

Hi Guys, Seems like many of you have a great deal of useful technical knowledge to spare. I have owned a 1990 300SL (129 UK delivery 12 valve ) for the past five years. For the most part it has given me a great deal of pleasure until my convertible roof started acting up last year. First all the hydraulic seals on the rams gave way, which after a great deal of difficulty i managed to replace through a long drawn out DIY repair.

Yesterday, after a couple of months of using the hardtop i decided to use the softop again, and to my dismay, the hood struggled to clim out of its compartment and stopped midway several times without completely closing, before finally stopping for good on about the 6th attempt. The Rollover bar does not move either now wheh i try to actuate it.

I have since closed the roof manually, and the warning light is off. When i use the convertible top swithch the light comes on, but all that happens is some clicking noises of solenoids in the back, but the pump doesnt seem to actuate to move anything. Hydraulic oil level in reservoir is adequate, and there are no leaks. Fuses are all OK as well.

Any suggestions? My local mechanic has suggested that the electronic roof controller unit may have packed it in?

Not sure if this is related, but last week prior to this, my dashboard was lit up like christmas lights apparently due to bad earthing somewhere in one of the door sensors, but is now fixed after a local electrician sorted it out.