msf766
Powell, OH, USA
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Joined: 06/16/2002
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Although not a camper towing issue, maybe someone can help out. Have a Dodge P/U with a 7-prong trailer plug. The horse trailer has a 6-prong plug, so I bought the appropriate adapter to connect the two. When plugged in all lights on the trailer work, but the trailer brakes lock up. When unplugged, the brakes work fine. I've cleaned all the grounds that I can find - truck, trailer lights, and trailer brakes. Any ideas as to what may be causing the brakes to lock when the electric connection is made? Thanks.
Matt
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BenK
SF BayArea
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Joined: 04/18/2002
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First you need to understand what each pin is/does.
Here is the list of things that need to get to the trailer via the connector.
Ground
+12 VDC
Running lights
Left blinker
Right blinker
Brake lite
Brakes
My guess that a six pin connector has the hitch ball/coupler make the ground connection or left off the +12 VDC.
If your brakes come on, then the brake wire is connected to the +12 VDC.
-Ben Picture of my rig
1996 GMC SLT Suburban 3/4 ton K3500/7.4L/4:1/+150Kmiles orig owner...
1980 Chevy Silverado C10/long bed/"BUILT" 5.7L/3:73/1 ton helper springs/+329Kmiles, bought it from dad...
1998 Mazda B2500 (1/2 ton) pickup, 2nd owner...
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Previous trucks/offroaders: 40's Jeep restored in mid 60's / 69 DuneBuggy (approx +1K lb: VW pan/200hpCorvair: eng, cam, dual carb'w velocity stacks'n 18" runners, 4spd transaxle) made myself from ground up / 1970 Toyota FJ40 / 1973 K5 Blazer (2dr Tahoe, 1 ton axles front/rear, +255K miles when sold it)...
Sold the boat (looking for another): Trophy with twin 150's...
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Kenneth
Washington, the state
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Joined: 03/20/2001
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Check your wiring against these drawings. It could be that your 7-pin is wired incorrectly...works together but won't work with the adapter.
Ken
I'm free of prostate cancer for 5 years now.
All men over age 50 should get an annual PSA blood test. Mine had a low reading, but the yearly jump was significant. The biopsy showed cancer just entering the aggressive stage. Dr. Hackenslash removed it.
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George B
Northern CA
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Joined: 02/06/2003
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If your 7 pin on the Dodge is factory installed it is unlikely that there is a problem there. On the factory plug, one pin is hot with 12 volts all of the time to power lights and keep the battery charged on the trailer. I would suspect that this is energizing your brakes. You are going to have to dig into the trailer wiring so why don't you install a 7 pin on the trailer at the same time?
George B
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twaldher
Bremerton, WA
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Joined: 10/14/2003
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The horse trailer was last towed by a Ford wasn't it.
The trailer wire harnesses have generally accepted industry standards.
Dodge/Chrylser - for as long as I know, at least 94 and up have used those standards.
At LEAST Ford hasn't and they do their own thing. Which means re-wiring the plub on either the truck to match standards or the RV to match the truck.
I have to do this all the time for people that borrow my car hauler. Hauler and truck are wired industry standard, Ford aint.
1996 Dodge RAM 1500 4x4 5.9L-V8, Auto, 3.92 Gears
1978 19' Wilderness Trailer
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thefb
Walla Walla, WA
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Joined: 05/23/2004
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there are two adapters to go from 7 to 6 pin wiring, go to your farm supply/hardware store and they will carry both- apparently there were two standards for 6 pin wiring, I had the same prob pulling an implement trailer, now I carry both adapters with me. I dont remember which pins are shuffled but it seemed more effective to carry both adapters than rewire the truck or trailer.
Good Luck
'04 Dodge 2500 4WD, CTD, auto, long bed, quad cab
'07 Arctic Fox 990
'04 Desert Fox 21SW Toyhauler
(do I need both?)
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