W169 Towbar

[Biggles1957]

Further to my last question about fitting a tower to my 2006 A Class, I've established that it is labelled for towing and have found a couple of what look like decent tower kits. The supplier also sells a relay but can you simply tag into the relevant wires at the back of the car or does it throw a wobbly because of things like CANBUS etc? Anyone know if you have to get a special kit or something (no doubt at great expense!)? Many thanks as always!

 

[Jim2]

I have recently transferred a towbar from my 2010 E class W212, where I used an external relay which worked perfectly in that car....you took trigger wires from each of the connections at the tail lamps, connected them to the Relay, and then out to the actual lights. In the 2010, all worked perfectly. In your 2006 A class, it should work out fine. Just check if there is a two filiment Brake / Park bulb with two wires feeding it in the taillamp. Dont worry, if you want to try it, its completely isolated from the CANBUS in any way that would affect it. Keep us informed how you get on, or if you have further questions.

Personally,fast forward to a few mths ago, and I upgraded to a 2014 MB 220 E class..The fitting was no problem..identical to the 2010 model. Then while the l+R indicators worked fine, I had a problem with the Brake / Park lights...this is because power is supplied by a single wire, which feeds a singe bulb / led, and when you press the brake, it sends more power to the bulb, causing it to glow brighter. So I made some enquiries , and was told that I would need a "Smart" Relay, which I got and installed per instructions. Still did not work for me. Having said that, its very possible that the mistake is on my side ( would not be the first time...) So at this point, its still a work in progress, and hoping that some one here on the forum will have successfully installed a relay system to their car.

 

[Biggles1957]

I have recently transferred a towbar from my 2010 E class W212, where I used an external relay which worked perfectly in that car....you took trigger wires from each of the connections at the tail lamps, connected them to the Relay, and then out to the actual lights. In the 2010, all worked perfectly. In your 2006 A class, it should work out fine. Just check if there is a two filiment Brake / Park bulb with two wires feeding it in the taillamp. Dont worry, if you want to try it, its completely isolated from the CANBUS in any way that would affect it. Keep us informed how you get on, or if you have further questions.

Personally,fast forward to a few mths ago, and I upgraded to a 2014 MB 220 E class..The fitting was no problem..identical to the 2010 model. Then while the l+R indicators worked fine, I had a problem with the Brake / Park lights...this is because power is supplied by a single wire, which feeds a singe bulb / led, and when you press the brake, it sends more power to the bulb, causing it to glow brighter. So I made some enquiries , and was told that I would need a "Smart" Relay, which I got and installed per instructions. Still did not work for me. Having said that, its very possible that the mistake is on my side ( would not be the first time...) So at this point, its still a work in progress, and hoping that some one here on the forum will have successfully installed a relay system to their car.

Many thanks Jim. I was thinking that as I'll only occasionally use a small trailer with my bobabout the simple relay system would probably be fine. My car does use filament bulbs as you say - good to know its isolated from the CANBUS though! My 1934 Morris Oxford is soooo much easier to work on - unless you're a young garage mechanic in which case they don't have a clue! Regards, Bob

 

[Jim2]

Many thanks Jim. I was thinking that as I'll only occasionally use a small trailer with my bobabout the simple relay system would probably be fine. My car does use filament bulbs as you say - good to know its isolated from the CANBUS though! My 1934 Morris Oxford is soooo much easier to work on - unless you're a young garage mechanic in which case they don't have a clue! Regards, Bob

In my ( misspent ) youth and prime, I worked for main a Morris Dealership,so I know exactly what you are talking about..when you could pull a plug lead off a running engine, and lived to tell the tale..good luck with the towbar electrics,,, you will be fine

 

[Jim2]

Back again after a 2 year absence, when I went back to my VW roots, before returning to the fold! And again, same Towbar issue, this time with a 2018 E class w213 so I presume that it will have its own headaches!! Ditto changing the transmission fluid, which will be much different from the last two changes I did in my two previous MB's all w212's 7 speed transmission, but this one is completely different, according to the U tube videos anyway,