nothing from trailer plug?
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Tuned
Joined: Feb 2010
Posts: 299
Likes: 6
From: South NJ
nothing from trailer plug?
I only tow a coouple of times per year... but seem to have electrical "gremlins" just about every time
Was hooking up, and the LH brake light on the trailer was working intermitently... seemed to change when "wiggeling" the plug. So I went on and hooked up the brake controller and got the "baseline" settings.
Next thing I know my friend tells me tht the LH brakelight on the truck doesn't work (but the 4-ways do)...
Now NOTHING works on the trailer - no lights or brakes. I put the meter on the pins of the plug on the truck - all zero. Checked some of the fuses, they are all OK.
What should I be looking for? I couldn't find a similar thread. Any ideas appreciated. (Today the brake lights on the truck are all fine.)
Was hooking up, and the LH brake light on the trailer was working intermitently... seemed to change when "wiggeling" the plug. So I went on and hooked up the brake controller and got the "baseline" settings.
Next thing I know my friend tells me tht the LH brakelight on the truck doesn't work (but the 4-ways do)...
Now NOTHING works on the trailer - no lights or brakes. I put the meter on the pins of the plug on the truck - all zero. Checked some of the fuses, they are all OK.
What should I be looking for? I couldn't find a similar thread. Any ideas appreciated. (Today the brake lights on the truck are all fine.)
Senior User
Joined: Dec 2009
Posts: 147
Likes: 0
From: Cuyahoga Falls, OH
Is your problem with the same trailer or different ones? I would check all the trailer wiring. Look for broken or pinched wires or check your ground connections for corrosion. Is this a factory installed plug or aftermarket installation?
Thread Starter
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Tuned
Joined: Feb 2010
Posts: 299
Likes: 6
From: South NJ
This is the same trailer - basically the only 1 I've ever had (the Expy is the 4th & best tow vehicle).
The change from "almost working" to "NOTHING" [from the truck] happened while sitting still in the garage.
Will look at those connectors, but doesn't seem like it would change sitting still??
Thanks
Mark
The change from "almost working" to "NOTHING" [from the truck] happened while sitting still in the garage.
Will look at those connectors, but doesn't seem like it would change sitting still??
Thanks
Mark
Freshman User
Joined: Dec 2010
Posts: 36
Likes: 0
From: Littleton CO
Check where the 7 way is wired into the truck's wiring. If "factory" it should be plug between the truck harness and also plug into the back of the 7 way socket.
If the truck lights are working, I'd look between the "splice" and socket.
Mag chloride and salts do wonders to wiring/connectors that isn't sealed.
Probe the splice with a test light or volt meter and find power from lighting. Work back from "good" until you find the issue. If the truck is without lights also, work forward until you find power and the problem should show up. Once the problem is found/fixed. Seal wires (if broken/repaired) and use dielectric grease on connectors. If your problems are butt connectors or snap on electrical connectors, replace them with shrink seal connectors.
If the truck lights are working, I'd look between the "splice" and socket.
Mag chloride and salts do wonders to wiring/connectors that isn't sealed.
Probe the splice with a test light or volt meter and find power from lighting. Work back from "good" until you find the issue. If the truck is without lights also, work forward until you find power and the problem should show up. Once the problem is found/fixed. Seal wires (if broken/repaired) and use dielectric grease on connectors. If your problems are butt connectors or snap on electrical connectors, replace them with shrink seal connectors.
Fleet Owner
Joined: Apr 2008
Posts: 24,322
Likes: 5,132
From: 0,0,1
The 20-amp fuse #10 is probably blown or otherwise not making a good connection. If that fuse does check out, then check for power at tow relays 05, 201, & 301 located in the fuse box.
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Postmaster
Joined: Sep 2010
Posts: 3,472
Likes: 2
From: Southern Cal
Now NOTHING works on the trailer - no lights or brakes. I put the meter on the pins of the plug on the truck - all zero. Checked some of the fuses, they are all OK.
What should I be looking for? I couldn't find a similar thread. Any ideas appreciated. (Today the brake lights on the truck are all fine.)
What should I be looking for? I couldn't find a similar thread. Any ideas appreciated. (Today the brake lights on the truck are all fine.)
You can replace the fuse and probably blow it again right away or else you can trace back the wiring harnesses for bad connections. So many trailers use the snap connectors that ecam referred to, that they just get corroded and fail. 90% of the time when it's an intermittent issue, the ground connection is bad. I would start there although that won't usually kill a fuse unless it's enough to bridge a gap and spark with high resistance.
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Tuned
Joined: Feb 2010
Posts: 299
Likes: 6
From: South NJ
Can't explain how, when, or why - but the "socket" on the truck came loose from its plug (immediately behind it)... and all of the trailer-tow fuses (except the brakes) were blown. Once we re-assembled the plug, and replaced the fuses, all is OK.
(We probably had the plug/socket apart last year when trouble-shooting the brakes, maybe it was not fully engaged on re-assy??).
Everything is working now.
"All is well that ends well"... ?
Thanks for the input!
Mark
(We probably had the plug/socket apart last year when trouble-shooting the brakes, maybe it was not fully engaged on re-assy??).
Everything is working now.
"All is well that ends well"... ?
Thanks for the input!
Mark
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