roll bar control unit
 

HI all......

i've recently purchased a 1996 320sl and the orange rollbar warning light is lit on the dash and the led in the roll bar button is flashing....

everything works fine...windows roof and roll bar all operate from the switches

I took it to the dealer who read the codes and said it needs a replacement soft top control unit

i bought a replacement unit from someone breaking the same car, put this in but now nothing works, soft top or roll bar, the orange warning light is still on, the led in the roll bar button is now permanantly lit, and also the soft top switch is now lit red?????????

I've read through lots of previous posts but cant find anything similar..

can anyone help

thanks in advance

I was hoping you'd get a response, my 90 SL has the same issue (before).

I thought there was a roll bar control unit unit.

I haven't debugged it much either, other than the blinking dash lights. And I believe the roll bar will not pop up in an emergency.

If you find out what it is, let me know.
When I decide to attack the issue, I'll post it here too.

The roll bar controller for a 90 is different then the controller for a 96. The system evolved over the years. The 90 is much simpler and easier to reset without going to a dealer. You can build a simple home made tool from radio shack parts for the 90 which can scan and reset the error codes. It's possible in either case that you have a tripped or bad rollover switch. There are a pair on the rear axle. Much has been written on the roll bar controller and how to build the tool. Use the forum search feature.

Thanks tecqboy.
I did not know there was a difference between the years.

I have gone through those tests, and checked the rear switches.
The answer was the controller is bad, but I wanted to rerun everything and double check. Haven't had the time.

Also being pretty handy etc, I also planned to remove the unit, check it, and check and clean all the connectors.
Unfortunately I have the rear seat option (aftermarket) so it's a pain to remove and get to the controller. Not difficult, just a pain.

Thanks

With the original controller, did you push and hold the rollover bar switch for 10 sec until you hear it click for a reset? Then raise and lower the bar with that same switch and see if the lights go out.

Why did they say you need a new controller? The first thing I would have done would be to take it to an Indy who has an advanced diagnostic tool like the STAR Diagnostic Scan tool and read and erase any/all codes for about $50.00 in the US.

There are 3 different p/n's for a 1996 R129 RST controller. You probably need the same p/n. Did you match the p/n with your cars p/n?

p/n 129820 3126

p/n 129820 3226

p/n 129820 3926

For a good review and a $375.00 rebuilt RST controller w/ a lifetime warranty check out http://www.bba-reman.com/catalogue/Products.aspx?category=633