Keyless in an 86 300SDL....actuator or not?
 

I'd like to put a keyless entry unit into an 86 300SDL and I'm coming to my fellow MB brethren for help. So far I haven't found a solid-state unit behind the back seat like I thought I would, nor can I find one in the trunk. Is another actuator needed in the door or is there a solid-state unit hiding somewhere I can splice into? TIA

What solid state unit are you looking for? The central locking system of the SDL runs off a pneumatic pump. Check the archives for fitting a remote keyless entry system to such a system. You need a system that can be configured to provide a pulse for something like 2 seconds. Many but not all RKE systems have such a feature.

Sixto
95 S420
87 300SDL
83 300SD ... $1100, see cars forum

I searched already but didn't find any definitive answers. I remember seeing something about a unit down behind the rear pass/side wheel but I didn't see anything like that. The only thing I saw was the actuator for the fuel door. I'll search again. Re: solid-state unit, I meant some type of controller circuit that I could splice into for the keyless receiver. Thanks.

There's no such circuit, it's all mechanical. The door and trunk lock switches send a 12V or ground signal to the pneumatic pump depending on switch position. The pneumatic pump has internal mechanisms to to await a lock signal when it's unlocked and an unlock signal when it's locked.

I seem to remember the name of B. Greer associated with finding the simplest solution to RKE in these cars. Expand your search to find solutions for 300E or W124. Same central locking system.

Oh, and if your factory alarm is still active, you'll really need those instructions since there's a separate switch in the door and trunk locks that activate the alarm.

Sixto
95 S420
87 300SDL
83 300SD

Thanks, Sixto. It's practically pitch-black dark out now so I'm calling it quits for today but I think I just found the unit. If this is it, it's sitting right next to the spare in the trunk. It's encased in foam rubber with a bunch of vacuum lines emenating from it. I'll search around on the board again. Thanks again.

That's the central locking unit.

This is the thread and the fellow's handle is bstreep, not B. Greer (sorry, Bill) - http://www.peachparts.com/shopforum/tech-help/11777-i-did-keyless-entry-your-124-made-easy-less-than-%24100.html?highlight=300e+remote+keyless

FWIW, I don't think Crutchfield sells the relay pack anymore. It's easy to make your own, though.

Sixto
95 S420
87 300SDL
83 300SD ... $1100, see cars forum

OK, I found the info. Thanks, Sixto. This'll be next weekend's project. :cool: