Buying an R350 - Question regarding towing
01-03-2012, 01:53 AM
#1
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Thread Starter
Buying an R350 - Question regarding towing
Just finalized purchase of a new 2012 R350 BlueTEC today. It should arrive late March. We are new to MB, but have been considering one for quite a while. My wife and I really liked the car on the test drive; fits two dog crates in the back. 
I understand from the sales representative that the factory installed trailer hitch package we ordered will include a standard seven pin connector for the trailer. He mentioned a brake controller is not included in the package.
Has anyone any experience with adding a controller to the R-Class? I have looked thru the archive posts quite a bit, and only see references to the GL, M, & GLK regarding controllers and towing.
Really hoping the R is at least now pre-wired now for a brake controller at the driver's position? Any instructions / technical info available to install? Hoping I can do this myself?
thx
Stu
Calgary AB Canada
I understand from the sales representative that the factory installed trailer hitch package we ordered will include a standard seven pin connector for the trailer. He mentioned a brake controller is not included in the package.
Has anyone any experience with adding a controller to the R-Class? I have looked thru the archive posts quite a bit, and only see references to the GL, M, & GLK regarding controllers and towing.
Really hoping the R is at least now pre-wired now for a brake controller at the driver's position? Any instructions / technical info available to install? Hoping I can do this myself?
thx
Stu
Calgary AB Canada
01-17-2012, 07:48 AM
#2
Member
What are you going to TOW?
For you to need an electric brake "Really hoping the R is at least now pre-wired now for a brake controller at the driver's position?" what in the world are you planning to tow? It's a car not a pick -up with the 5th wheel kind of thing. I've never heard of needing one, I think you would be over the design limits if you did.
01-18-2012, 01:18 PM
#3
Junior Member
Thread Starter
Thx for the reply.
The trailer I have in mind is equipped with electric brakes rather than surge brakes, hence the need for a controller to be able to use it as configured. Expect the weight of the trailer and load will be within 3,500 lb NA towing limit of the vehicle. The weight of the trailer without load is ~1300 lb. I understand the towing limit on the R class overseas is 4,600 lb, so pretty sure no issues with what I have in mind.
In my area, trailer brakes are required if the trailer weight exceeds 2004 lb, well within the towing limit of the R. A common weight limit for brakes in other areas is 3,000 lb, again within the towing capacity.
I take it you don't know if the car is pre-wired? Apparently the GL & ML are now pre-wired, but unsure about the R-Class. Have attached the TSB regarding the wiring configuration, which is quite involved if not pre-wired.
Think I may have found a solution with the Prodigy RF if not pre-wired, but it is a bit spendy.
http://www.etrailer.com/Brake-Contro...sha/90250.html
thx
The trailer I have in mind is equipped with electric brakes rather than surge brakes, hence the need for a controller to be able to use it as configured. Expect the weight of the trailer and load will be within 3,500 lb NA towing limit of the vehicle. The weight of the trailer without load is ~1300 lb. I understand the towing limit on the R class overseas is 4,600 lb, so pretty sure no issues with what I have in mind.
In my area, trailer brakes are required if the trailer weight exceeds 2004 lb, well within the towing limit of the R. A common weight limit for brakes in other areas is 3,000 lb, again within the towing capacity.
I take it you don't know if the car is pre-wired? Apparently the GL & ML are now pre-wired, but unsure about the R-Class. Have attached the TSB regarding the wiring configuration, which is quite involved if not pre-wired.
Think I may have found a solution with the Prodigy RF if not pre-wired, but it is a bit spendy.
http://www.etrailer.com/Brake-Contro...sha/90250.html
thx
Last edited by stugilmour; 01-18-2012 at 01:32 PM.
01-19-2012, 10:11 PM
#4
Super Member
Thx for the reply.
The trailer I have in mind is equipped with electric brakes rather than surge brakes, hence the need for a controller to be able to use it as configured. Expect the weight of the trailer and load will be within 3,500 lb NA towing limit of the vehicle. The weight of the trailer without load is ~1300 lb. I understand the towing limit on the R class overseas is 4,600 lb, so pretty sure no issues with what I have in mind.
In my area, trailer brakes are required if the trailer weight exceeds 2004 lb, well within the towing limit of the R. A common weight limit for brakes in other areas is 3,000 lb, again within the towing capacity.
I take it you don't know if the car is pre-wired? Apparently the GL & ML are now pre-wired, but unsure about the R-Class. Have attached the TSB regarding the wiring configuration, which is quite involved if not pre-wired.
Think I may have found a solution with the Prodigy RF if not pre-wired, but it is a bit spendy.
http://www.etrailer.com/Brake-Contro...sha/90250.html
thx
The trailer I have in mind is equipped with electric brakes rather than surge brakes, hence the need for a controller to be able to use it as configured. Expect the weight of the trailer and load will be within 3,500 lb NA towing limit of the vehicle. The weight of the trailer without load is ~1300 lb. I understand the towing limit on the R class overseas is 4,600 lb, so pretty sure no issues with what I have in mind.
In my area, trailer brakes are required if the trailer weight exceeds 2004 lb, well within the towing limit of the R. A common weight limit for brakes in other areas is 3,000 lb, again within the towing capacity.
I take it you don't know if the car is pre-wired? Apparently the GL & ML are now pre-wired, but unsure about the R-Class. Have attached the TSB regarding the wiring configuration, which is quite involved if not pre-wired.
Think I may have found a solution with the Prodigy RF if not pre-wired, but it is a bit spendy.
http://www.etrailer.com/Brake-Contro...sha/90250.html
thx
Its not just your area that needs brakes on big trailers. anything over a couple thousand pounds need brakes. Its not rocket science to install. As your PDF suggested, all you need is a 30 amp circuit and a break signal.
01-23-2012, 02:14 PM
#5
Junior Member
Thread Starter
Thx for the reply.
I see for PQ the weight limit is similar to AB:
Agree it looks pretty straight forward schematically, but hoping I don't have to fish the wires thru the interior to the driver's position and the existing R-Class wiring / equipment provides the correct updated SAM and an easy connector that is not disrupted by the controller addition. Several years ago when I was considering a GL there was a ton of discussion on guys trying to get things to work correctly, so curious to see if the R-Class got the same updates. Looks like I will have to wait until I get the car end of March prior to purchasing a trailer.
I see for PQ the weight limit is similar to AB:
Independent RV braking system is required in each weight bearing wheel where gross weight exceeds 1,300 kg (2,867 Lbs). Breakaway brakes are required on all trailers 1,360 kg (3,000 Lbs) and over.
02-26-2012, 03:14 PM
#6
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R350
The wiring harness for the R-class is not set up for electric trailer brakes. The ML and GL class are the only ones ready for a brake controller, but you can easily buy one of those to replace the factory harness as the plug socket and rear SAM are the same on the ML, GL, and R.
The part numbers for the wiring harness that have a plug for the brake controller are:
ML - A 164 440 15 39
GL - A 164 440 64 34
Note: the wiring harnesses that are set up for the electric brake will have an additional +12V line that connects to position 71 of the fuse box and should be fused at 30A. The factory harness for the R-class only has a single +12V line (battery power to the plug socket), which connects to position 70 on the fuse box and is fused at 20A.
The part numbers for the wiring harness that have a plug for the brake controller are:
ML - A 164 440 15 39
GL - A 164 440 64 34
Note: the wiring harnesses that are set up for the electric brake will have an additional +12V line that connects to position 71 of the fuse box and should be fused at 30A. The factory harness for the R-class only has a single +12V line (battery power to the plug socket), which connects to position 70 on the fuse box and is fused at 20A.
11-19-2013, 08:48 PM
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2011 Mercedes ML350 BlueTec
164 440 15 39 Glad to hear this is all ready for a brake controller. However, a concern is the brake switch lead. My 2011 MB ML350 BlueTec has a CAN-BUS system. If it has a brake switch in which I can connect the Prodigy P3 brake switch lead, the electrical load (although very little) may conflict with the CAN-BUS and not work or cause errors. Do you know if this is a concern? Thanks.
Alan
Alan
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11-19-2013, 09:20 PM
#8
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164 440 15 39 Glad to hear this is all ready for a brake controller. However, a concern is the brake switch lead. My 2011 MB ML350 BlueTec has a CAN-BUS system. If it has a brake switch in which I can connect the Prodigy P3 brake switch lead, the electrical load (although very little) may conflict with the CAN-BUS and not work or cause errors. Do you know if this is a concern? Thanks.
Alan
Alan
Actually, since the R, ML, and GL use the same SAM, the only differences in the wiring harnesses are the wire lengths and the R-class doesn't have the connector for a brake controller.
The 4-pin plug (for the brake controller) from the hitch wiring harness has the +12V, Gnd, stop light from the SAM and the trailer brake to the trailer hitch plug.
