ND4SPED

New here just pulled the trigger on a 09 GL320 can you guys help me with a recommendation on a brake controller. I have been using a Draw Tite Intella Stop Ultra controller on the my old Escalade wanted to know what you guys are using. Towing my car trailer and track car about 5500 lb. total towing.
Thanks for the advice

Brocktoon

I have a tekonsha Primus, but I should have spent the extra two bucks on a Prodigy...

ND4SPED

Thank you for the info were you able to plug & play with a wiring harness for the GL and if so do you have the information on the harness.
Thanks again

nkole

I have the Prodigy.

Bought a plug and four pins at the dealer. Was able to solder the the cable that came with the Prodigy to the pins and it pluged right into the cable that's taped up under the dash. Everything works great. I tow a 16 foot flatbed trailer.

scottybdiving

There is a topic here somewhere that includes up close detailed photos of the plug.

ND4SPED

Thanks for all the advice will do the same
Thanks again

scottybdiving

Found it HERE. 3rd Post. A PDF file.

nkole

Yup, that's the PDF I used to purchase the plug and pins and to figure out which wire from the Prodigy goes to which pins.

Neil

ND4SPED

You are the best thank you for all your advice

Danno4x4

Yep, that is exactly what I did... Its actually pretty easy to do...

I currently have a Tekonsha Prodigy. Nice controller... It does everything that I need it to...

However, after I bought the Prodigy, Tekonsha came out with their new P3. This is a really fancy controller, it is their new top of the line and while it does everything that the Prodigy does, it does it in a way cooler fashion.

While you are assembling the wiring harness, be sure to include a 20 to 30 AMP auto reset circuit breaker as shown in the wiring instructions for the Brake Controller. The Mercedes PDF does not show this, but the Tekonsha instructions do... It is pretty simple to do... Just get a blade style fuse holder... Take a look at this earlier post to see a bit more detail:

https://mbworld.org/forums/gl-class-...ntrollers.html

ND4SPED

Just got the Tekonsha P3 Brake Controller installed hooked up the toy hauler and it worked perfect. Thanks for the advice. For information if anyone with a '09 320 GL they had to install it under the parking brake as pictured due to the air bag was to the right.

On another note having issue with the coupler for some reason hitch ball is moving forward and backward inside the coupler. 2 5/16 ball which is the correct size for the standard 2 5/16" a-frame coupler. Is their any way to adjust the coupler?
Thanks again

scottybdiving

One time I loaned a trailer to a friend who had his 2 5/16 ball that he uses for his travel trailer. My coupler (bull dog style) would not close on his ball hitch, which was clearly marked 2 5/16. He ended up using my receiver hitch and ball, which is also clearly marked 2 5/16, to tow the trailer, so there might be some slight variations. This goes against reason and there should be very stringent tolerences but that is what we found.

ND4SPED

Great point I had to put another hitch I had in my garage of parts on the GL because I had a 10" Drop adjustable with a 2 5/16" ball on my Escalade ( former ) it worked great. I could not put it on because it hit the ground on the GL. I will try another ball. Thank you

kerlyb

Why the need for the circuit breaker?

Danno4x4

Without the circuit breaker, in a momentary overload situation, the fuse will blow for this circuit... Then you are completely out of trailer brakes until you replace the fuse... With an auto-reset circuit breaker, it will auto reset itself... and you will still have trailer brakes...

Manufacturers use the same setup for headlights... In a temporary overload, the lights will simply blink off and then back on when the breaker resets itself...

BETO

I had the stealer installed me a brake controller when I bought the truck, they got the cheapest controller from checkers, and have worked just fine towing my open trailer and race car for two years.
I hate car wiring, specially in a Mercedes. I had to go thru a lot of trouble for a Land Rover before so this time I got the stealer doing it for me.

Stoneseller

Any new info on installing a controller?
I have a new 2010 on order, due end of April.
Any / all recommendations on controller brand/models & install tips greatly appreciated.

David in MD

ND4SPED

Check this link out. Went with the Tekonsha P3 Brake Controller no issues with it to date
https://mbworld.org/forums/gl-class-...ce-please.html

awx1144

How do I install a brake controller on a GL450? Dealer says not needed - I'm not so sure. I will be towing a 7500 pound 3 horse trailer. Thanks!

ND4SPED

You do need a controller my dealer installed mine. It is a plug & play you should have the plub already in the truck.

awx1144

Thanks for the quick reply? Where is the plug located? This is for a 2007 model.

ND4SPED

Not sure thought is was newer may not have the plug. I would call MB.
I will see what I can find out for you as well

Stoneseller

All vehicles produced after Dec 06 have the plug under the dash.
The early production 07's had the plug in the back.

awx1144

Thanks. I think this is the case here. From the carfax, it looks like the car was originally sold in Dec '06 so it may have the plug in the back. Where in the back would it be located? Does the wiring have to be pulled to the front?

Do you recommend this vehicle for towing or should I stick with a domestic truck?

My trailer dealer suggested using a RF brake controller instead of hard wiring. Has anyone tried this?

Thanks again for all your help. I'm nervous about spending this much money if it is not the right vehicle for the job.

ND4SPED

The controller will need to be in the front under the dash level to the vehicle. I have a picture of mine install if you look a few clicks up the this page.
This vehicle will tow like a chap no issues I pull a 28 ft enclosed trailer all over the country and get 17 to 18 mpg at 65 mph.
I would hard wire the controller! Is this a MB dealer sounds to me like you may need to bring this to someone who know at best where the plug is.