I purchased an 07 GL 450 with a factory installed hitch. Bought the 5 pin plug and thought that was all I needed to do. Noticed that the trailer lights didn't work so took a look in the rear fuse box. There are no fuses installed for trailier wiring (70, 71, 72). Is there a module I need to purchase or simply the fuses? Does a dealer have to do the install (if a module is needed) or can a trailer hitch place accomplish this?

 

If it is, indeed, a "factory installed" hitch and not one purchased afterwards, it should have any module needed to run the brake lights (which also, by the way, adjusts other settings in the GL automatically, such as turning off the rear parking distance sensors and setting up the traction control to assist with trailer sway). If it was NOT installed at the factory, you may need to purchase the trailer control module that is installed with the trailer hitch. If so, sorry, it's expensive.

My own advice is, don't tow until you know.

STP

 

thx. I guess I cannot confirm that it was factory as I bought the vehicle used. It is not a drawtite, Uhaul, etc and fits flush with the vehicle. Anyway, if I need the module and it looks as if I do (there is no where for to fuses to plug into) does the dealer need to install and if so (gulp) how much does it run?

 

dinbri1:
Go to http://www.startekinfo.com/StarTek/s...by_chassis.jsp and sign up (no charge for US owners), then enter your VIN. You will find the list of all factory installed options there. If you see the factory hitch there you are OK. There were several 'recall' type events involving the Signal Acquisition Module (SAM) which is the computer involved with operating with a trailer. (This - the SAM - is the reason the dealer add on of the hitch is so expensive). After you make this determination, you SHOULD check with a dealer to determine if all the computer updates involving the SAM (with factory hitch) have been done. If they weren't they should be done under warranty.

 

There's also a safety recall on the factory hitch--some additional wiring.

Your dealer will perform this recall for anyone at any mileage and at any age until it's done. Check with dealer to see if yours has been done. This will give you a quick idea whether your hitch was factory installed, as they will have records of that.

 

Wasn't there also one involving some weld problems?

 

Okay, I'm a moron - no charge for US owners? I tell 'em I want to sign up and they say I have to subscribe for pay. Am I missing something?

STP

 

Sorry if M-B changed policy since I signed up. I know my 'free' access was good until the end of August (one year since I signed up) but I haven't had occasion to try since so I don't know what happens now. Maybe lkchris (Kent) knows for sure. I DO know you have to give them a credit card number but it is NOT charged a fee.

 

Yes, a typo. It's welding, not wiring.

 

What's free is the parts system (EPC) but not the service manual system.

The VIN check is in the parts system (called a datacard).

They ask for a credit card when subscribing to the free parts system only to verify you live in USA because this service is only available to USA residents. They don't charge the card.

 

Thanks again Kent!

 

So I could find out what part to order to, say, replace the LEDs under the mirrors, but not how to properly replace them without damaging the mirrors themselves?

Interesting.

Thank you, Kent!

STP

 

The factory installed plug is a 7 pin plug. Most trailers won't use all 7 so you will need an adaptor down to 5 or 4 depending on you trailer needs.