Picked up GL320..problem with trailer wiring
Thread Starter
Junior Member
Joined: Dec 2006
Posts: 27
Likes: 0
From: Nashville, TN
GL450
Picked up GL320..problem with trailer wiring
We picked up the GL over the weekend. Everything is awesome except I was test connecting to my car trailer (for racing) and it looks like everything works except the running lamps circuit is not getting any power.
Brake controller hooked up no problem and all light and brakes work except when I turn on the headlights, no lights on the trailer.
Anyone with a similar experience? I have an appointment to take it in tomorrow to have the dealer look at.
Thanks,
Bill
Brake controller hooked up no problem and all light and brakes work except when I turn on the headlights, no lights on the trailer.
Anyone with a similar experience? I have an appointment to take it in tomorrow to have the dealer look at.
Thanks,
Bill
Senior Member
Joined: Dec 2006
Posts: 405
Likes: 1
From: Scottsdale, AZ
2007 GL320 CDI, 2001 TJ Rockcrawler, 2005 Scoobie STI
Hmm, thats interesting...
I had no problems with my hookup... Glad the TB controller is working well... I believe that some folks were having trouble with that one...
If you have a 12 volt circuit continuity/voltage tester you can check to make sure that the green wire is putting out any voltage from the vehicle when the lights are turned on...
If you look at this diagram (the left side is if you are facing the vehicle female side of the plug, and the right side is if you are looking at the male trailer side of the plug) you can touch the green wire terminal and the white wire terminal with the tester. If there is voltage here, they problem is with the trailer wiring, if not, its with the vehicle.
I had no problems with my hookup... Glad the TB controller is working well... I believe that some folks were having trouble with that one...
If you have a 12 volt circuit continuity/voltage tester you can check to make sure that the green wire is putting out any voltage from the vehicle when the lights are turned on...
If you look at this diagram (the left side is if you are facing the vehicle female side of the plug, and the right side is if you are looking at the male trailer side of the plug) you can touch the green wire terminal and the white wire terminal with the tester. If there is voltage here, they problem is with the trailer wiring, if not, its with the vehicle.
Thread Starter
Junior Member
Joined: Dec 2006
Posts: 27
Likes: 0
From: Nashville, TN
GL450
Danno -- Thanks for the reply.
Found out there was not power to the tail light circuit. Took it into the dealer to day.
They replaced the SAM and reprogrammed. Will test it tonight.
BTW, I think the diagrams are the reverse. Right is truck and left is trailer. At least that's what it shows on the socket on the truck.
Thanks.
Found out there was not power to the tail light circuit. Took it into the dealer to day.
They replaced the SAM and reprogrammed. Will test it tonight.
BTW, I think the diagrams are the reverse. Right is truck and left is trailer. At least that's what it shows on the socket on the truck.
Thanks.
Newbie
Joined: Feb 2008
Posts: 2
Likes: 0
From: Park City, UT
BMW X3, Mini Cooper S, Porsche GT3, Porsche 911 Speeder
Hello wbrownie. Met you over on the Rennlist GT3 board. I am really interested in a GL as a track puller/winter DD. My core concern is itsability to handle deep snow & ice. We get too much of it here in the mountains...
Let me know how you like the CDI. My wife and I are 50/50 right now on gas versu diesel.
Thanks,
-Blake
Let me know how you like the CDI. My wife and I are 50/50 right now on gas versu diesel.
Thanks,
-Blake
Thread Starter
Junior Member
Joined: Dec 2006
Posts: 27
Likes: 0
From: Nashville, TN
GL450
Hello wbrownie. Met you over on the Rennlist GT3 board. I am really interested in a GL as a track puller/winter DD. My core concern is itsability to handle deep snow & ice. We get too much of it here in the mountains...
Let me know how you like the CDI. My wife and I are 50/50 right now on gas versu diesel.
Thanks,
-Blake
Let me know how you like the CDI. My wife and I are 50/50 right now on gas versu diesel.
Thanks,
-Blake
We don't really get much snow here in middle TN so can't really speak to that. I did test the towing over the weekend. Loaded up the GT3 into the trailex and went for a test drive.
Observations:
Power on the diesel is more than adequate for towing. Weight of the car and trailer is about 5500 pounds.
The side mirrors are WAY too small. Couldn't see a thing. Ordered suction type extensions from Camping World.
Overall is very stable towing. Will need to play with the placement of the car a bit to optimize stability.
Diesel takes some time getting used to. Power delivery is obviously different than gas so you just need to get used to it and drive accordingly. Oh and the mileage is awesome. Got 15 on my short towing excursion, getting 18 around town and got mid 20's on a short highway trip.
Overall I'm pleased. Will be towing down to Barber (about 200mi each way) in about a week.
Bill
Thread Starter
Junior Member
Joined: Dec 2006
Posts: 27
Likes: 0
From: Nashville, TN
GL450
Danno -- Thanks for the reply.
Found out there was not power to the tail light circuit. Took it into the dealer to day.
They replaced the SAM and reprogrammed. Will test it tonight.
BTW, I think the diagrams are the reverse. Right is truck and left is trailer. At least that's what it shows on the socket on the truck.
Thanks.
Found out there was not power to the tail light circuit. Took it into the dealer to day.
They replaced the SAM and reprogrammed. Will test it tonight.
BTW, I think the diagrams are the reverse. Right is truck and left is trailer. At least that's what it shows on the socket on the truck.
Thanks.
Newbie
Joined: Feb 2008
Posts: 3
Likes: 0
From: Park City, UT
BMW X3, Mini Cooper S, Porsche GT3, Porsche 911 Speeder
Thanks Bill! I work for a company in Huntsville and will be there next Wed-Fri. With another Rennlist friend from Charlotte (formerly Nashville) we are both looking at attending the Barber event as "by-standers". Hope to see you there...
Thanks so much for the towing review on the GL. My wife needs to feel that the car can handle deep snow, and I need to know if it can tow my GT3 to west coast tracks. There are so many good ones to visit!
-Blake
Thanks so much for the towing review on the GL. My wife needs to feel that the car can handle deep snow, and I need to know if it can tow my GT3 to west coast tracks. There are so many good ones to visit!
-Blake
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Senior Member
Joined: Dec 2006
Posts: 405
Likes: 1
From: Scottsdale, AZ
2007 GL320 CDI, 2001 TJ Rockcrawler, 2005 Scoobie STI
Just my two cents.... With the OEM tires, my GL handled deep snow just fine (My experience is with 8-10 inchs of fresh stuff on a Colorado Mountain Road for 15 miles.) You can really feel the Vehicle Stability Control kick in around the corners, even if you purposely tried to stomp the throttle and spin it out, it won't let you...
Now if you add some Winter Tires to the equation, you are talking one stable machine.
Plus, it tows my 6340 lb rig with no problems at all. I wouldn't say that it does the job with the sturdyness of a 1 ton pickup, but I feel very safe towing from Phoenix, AZ to Moab, UT with my family onboard.
Check out post #70 on this link...
https://mbworld.org/forums/showthrea...+towing&page=2
Now if you add some Winter Tires to the equation, you are talking one stable machine.
Plus, it tows my 6340 lb rig with no problems at all. I wouldn't say that it does the job with the sturdyness of a 1 ton pickup, but I feel very safe towing from Phoenix, AZ to Moab, UT with my family onboard.
Check out post #70 on this link...
https://mbworld.org/forums/showthrea...+towing&page=2
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Newbie
Joined: Feb 2008
Posts: 3
Likes: 0
From: Park City, UT
BMW X3, Mini Cooper S, Porsche GT3, Porsche 911 Speeder
I saw that post after searching the archives, Danno. That looks like one potent off road machine! (And that Jeep looks good as well...)
Seriously, I feel alot better about towing based on that thread. Thanks for posting.
-Blake
Seriously, I feel alot better about towing based on that thread. Thanks for posting.
-Blake
Senior Member
Joined: Apr 2007
Posts: 252
Likes: 1
From: Central PA, Jersey Shore
'16 S550, '03 & '15 GMC Sierra 1500, '17 C300
For those of you who have used the hitch - was there a trailer adapter that came with the vehicle? Or do I have to purchase one at the local auto parts store?
Thread Starter
Junior Member
Joined: Dec 2006
Posts: 27
Likes: 0
From: Nashville, TN
GL450
You have to purchase one. Which one you purchase will depend on the trailer. Some may need a drop hitch. In my case, I needed about a 2 inch rise.
Senior Member
Joined: Dec 2006
Posts: 405
Likes: 1
From: Scottsdale, AZ
2007 GL320 CDI, 2001 TJ Rockcrawler, 2005 Scoobie STI
http://ultrahitch.rpmsolutions.biz/index.cfm?Section=73
These hitches are very versatile since they allow a drop or a rise... In the end, you want to use a hitch that allows the trailer to ride level, so if you plan to tow multiple types of trailers, adjustability is good to have.
Thread Starter
Junior Member
Joined: Dec 2006
Posts: 27
Likes: 0
From: Nashville, TN
GL450
As brownie mentioned, you will have to purchase/borrow/steal one. Its a little bit more expensive, but I would recommend an adjustable hitch like this one...
http://ultrahitch.rpmsolutions.biz/index.cfm?Section=73
These hitches are very versatile since they allow a drop or a rise... In the end, you want to use a hitch that allows the trailer to ride level, so if you plan to tow multiple types of trailers, adjustability is good to have.
http://ultrahitch.rpmsolutions.biz/index.cfm?Section=73
These hitches are very versatile since they allow a drop or a rise... In the end, you want to use a hitch that allows the trailer to ride level, so if you plan to tow multiple types of trailers, adjustability is good to have.
