Fourdiesel

Keep checking ebay for wheels in the size you are looking for. They come and go.

IridiumRoad

I have the same vehicle with the towing package, and yes, I had to have the rear SAM reprogrammed (1 hr labor). Before re-programming it would not power the brake controller correctly.

Fourdiesel

Did the dealer charge for the reprogramming? If they did I'm very surprised since you already paid for the towing package in the OEM price. All brands of proportional controllers (and M-B DOESN'T offer one) work on the same signal so the programming should not be dependent on the controller used.

nkole

No reprogramming is necessary.

danstl

I finally got around to doing this. Got the plug/pins from the dealer (who initially told me there was no such thing) and then bought a Prodigy controller. Took about 15 minutes to solder the pins and put the plug together, and about the same time to install it. I am not happy with where it is installed....can't really hang in under the dash due to the airbag, but it is not much in the way on the side of the console. All in all, I'm a happy camper.

Fourdiesel

I presume it works correctly WITHOUT any reprogramming issues??
I was wondering about the airbag thing - I'd read about that interference problem before but forgot to mention it.

Newbie_2_MB

I agree with STP...that is sad! My 3 Labs love the back of my 2007 450 and their dog snot/slobber has not hurt anything in the car. I take one of my Labs in the car every week when we go to the local hospital to do our therapy dog visits with patients.

I don't have kids, but honestly, I've seen cars that kids have been in & I'll take my doggy mobile over a kid mobile any day!

danstl

Fourdiesel...yes it works properly without reprogramming, but I have a 2009. Don't know about earlier models.

danstl

IridumRoad....I have a trailer with LED lights and the GL320 does not recognize it. I called ETrailer, and they had no idea what I was talking about. The Uhaul connector is for a 4-wire. My trailer is a 7-pin round with electric brakes. I don't think there is a 7-7 connector available. Anyone have any ideas on what to do to fabricate a harness? Now much resistance needs to be added? Where?

Thanks.

nkole

I think you need this:

http://www.etrailer.com/p-V39010.htm

Neil

danstl

nkole....that looks like the right thing. I ordered one. It won't get here quickly enough for my needs for this trip, but I do appreciate it. When I spoke with them on the phone, they didn't know what I was talking about. I was in their "showroom" a couple of years ago. It was smaller than my garage. They must warehouse everything somewhere else.

Thanks.

danstl

Received the cable from etrailer....works perfectly with my trailer with LED lights. Without the cable, the GL320 doesn't know the trailer is there.

IridiumRoad

FYI ... if anyone else needs the same LED adapter cable mentioned in previous posts, I happen to have a spare. Long story, but I ended up with two of them. The second one is new in box. First person to contact me and send $30 via PayPal can have it.

IridiumRoad

Update: I no longer have a spare cable to sell.

Texas993

Thanks to everyone who contributed to this post (including the links to other posts). This helped me to decide on the GL350 instead of the GL450.

We placed our order today!

Oh, and I tow my Porsche for weekends and Colorado summers.

awx1144

I am buying a certified preowned 2007 GL450 with tow package so that I can tow my 7500 lb. 3 horse trailer. The dealer says I do not need one - that the 7 point rear plug takes care of the brake signalling. The shop foreman says not to add one because all wiring is fiber optic.

Do I need to add an electric brake controller under the dash? Is it safe to tow without it? How do I install the brake controller? I am getting very nervous about towing with this vehicle. Please help!

IridiumRoad

The dealer is wrong: the GL does not have an integrated brake controller. It does have a 7-way plug if you get the towing package, but that only controls the trailer lights. It does not control the trailer brakes. You need a brake controller for that.

It is not safe to tow a 7500 lb trailer without brakes, nor is it legal in most states.

Ask for a copy of Star Bulletin T-B-31.19/07d. Don't believe anything the dealer or service manager tell you that contradicts that Bulletin.

Also, if your trailer's tongue weight is approaching 600 lbs (the placarded limit), you are at risk of breaking the OEM receiver hitch. It may need reinforcement.

mdadgar

Speaking of the 600 lb tongue weight limit, that is presumably for dead weight. Does anyone know what the load distributing limit is?

For example, my Escalade has a Class IV hitch which is marked with a sticker that indicates that the dead tongue weight is 600 lbs and the weight distributing limit is 1000 lbs.

What's the weight distributing limit for the GLs? It does not appear to be in the GL manual that I found online.

- Mark, contemplating a GL350

awx1144

Thanks for the information. I just bought the 2007 GL450 yesterday and now I am worried sick if I made an expensive mistake. The trailer tongue weight is 1,050 pounds. Loaded GVWR is 7,000 loaded, 3180 unloaded. What should I do to make this SUV safe for towing my trailer since I'll be hauling horses?

mdadgar

You definitely want to start with a weight distributing hitch.

The one I use is expensive compared to more common units, but it is AMAZING. I would not tow without it anymore.

www.propridehitch.com

Here's hoping we can get an answer to my post above.

- Mark

awx1144

I called my trailer manufacturer. He said the posted tongue weight on the jack is the load the jack can support, in my case 1050 pounds. He said that the weight resting on the hitch is 10% of the trailer weight - so if I am towing 6000 lbs, the weight on the hitch is 600 lbs. Hope this helps.

IridiumRoad

Mercedes doesn't publish that limit. Be advised, numerous owners have seen the receiver hitch on the Mercedes break when approaching or exceeding the 600 lb limit. Given the design of the receiver, my guess would be that the practical weight distribution limit would be lower than 600 lbs. The "torquing" effect of weight distribution concentrates stress on the weakest pair of welds on the receiver, and the welds fail.

BKR

Anybody have the part number for the brake controller plug/pins?

bselph

This was for my 2008 GL320

1ea green female connector housing-- A039 545 35 28
1ea pin 0.75 mm-- A046 545 40 28
3ea pin 2.5 mm-- A035 545 74 28

You will also need 4ea lengths of wire to run from the controller to the plug under the dash above the parking brake pedal.

shysmom

Does anyone know a good link to this product now? This one no longer works. I don't even know the name of it so that I could call and ask.