Electric Brakes????
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Postmaster
Joined: Apr 2001
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From: Baileyton, TN
Electric Brakes????
I have just purchased a new trailer, from someone over 500 miles away. The brakes are intermittant, causing the Prodigy brake controller to throw a small fit. 'SH' 'o.c. and 'oL' flash occasionally, and when moving forward, the brakes do not operate as expected. However, when stationary, they work find.
Pulling out the break-away engages the brakes fine too, so the problem is a little baffling. Does anyone have any suggestions for me? other than returning the trailer - that is not an option.
The trailer guy looked at it twice - I got 25 miles, the first time it did anything, and returned. He messed with the wiring some, showing eagerness, but not curing the problem. I got 2 miles the next time, and returned it. He looked some more, and messed with the wires again, called the manufacturer a couple of times, and generally helped as much as he could, but he is a trailer sales, not a trailer fixer.
Pulling out the break-away engages the brakes fine too, so the problem is a little baffling. Does anyone have any suggestions for me? other than returning the trailer - that is not an option.
The trailer guy looked at it twice - I got 25 miles, the first time it did anything, and returned. He messed with the wiring some, showing eagerness, but not curing the problem. I got 2 miles the next time, and returned it. He looked some more, and messed with the wires again, called the manufacturer a couple of times, and generally helped as much as he could, but he is a trailer sales, not a trailer fixer.
Posting Guru
Joined: Nov 2002
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From: Texas
Theologian--
Ever use your truck with a different trailer with brakes--if so, did they work?
It it doesn't work only when moving, I would suspect a 1) ground problem 2) problem with the truck connector 3) problem in trailer harness connector. Is the harness on the trailer molded one-piece or hand wired? Is the truck connector factory-installed or after-market?
Can you borrow another truck and test-tow with it? That would tell you if the problem is in trailer harness only. Same problem with another truck--trailer wiring; no problem with another truck--truck wiring.
Ever use your truck with a different trailer with brakes--if so, did they work?
It it doesn't work only when moving, I would suspect a 1) ground problem 2) problem with the truck connector 3) problem in trailer harness connector. Is the harness on the trailer molded one-piece or hand wired? Is the truck connector factory-installed or after-market?
Can you borrow another truck and test-tow with it? That would tell you if the problem is in trailer harness only. Same problem with another truck--trailer wiring; no problem with another truck--truck wiring.
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Joined: Sep 2000
Posts: 7,298
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From: Southern California
Theo, it does sound like a short somewhere on the trailer wiring or a bad ground on the brakes. Perhaps some insulation was chaffed during assembly causing a short. Or the electomagnets do not have a good ground.
I'm assuming you have the Prodigy mounted between 0 degrees and 70 degrees. Otherwise you would get a _._ display for too low or a -.- display for too high.
If you want to troubleshoot this problem yourself, get an inexpensive digital multimeter. First check the brake wire on the truck for voltage and continuity. Also make sure the ground wire pin is good. Pull the brake drums off the trailer axles. Inspect all the wires. Use the multimeter to test for voltage and continuity. Check from the plug back to the brakes on both the brake wire and ground wire. Testing each individual brake while supplying voltage from the Prodigy may shed light on where a short or bad ground might be.
Otherwise, since it's a new trailer you could take it to a trailer or R.V. repair. Assuming there was a problem with how your trailer was wired or assembled, the dealer/manufacturer should be willing to rebate your expense.
This data comes with the Prodigy, but I'll post it here for everyone else to see and perhaps come up with the correct solution for the problem:
Display: SH
Situation: Flashes 2 times per second:
Probable Cause: Brake wire sees short during idle condition.
Display: o.c
Situation: Flashes for 15 seconds.
Probable Cause:
1. Trailer not connected to tow vehicle.
2. Trailer connected withe open circuit on brake line.
3. Trailer connector disconnected or corroded.
4. Loss of trailer brake magnet ground.
Display: o.L
Situation: Flashes 2 times per second.
Probable Cause: Prodigy "sees" an overload condition during operation.
Display: .c
Sitiation: Normal. Power to Prodigy with trailer connected.
I'm assuming you have the Prodigy mounted between 0 degrees and 70 degrees. Otherwise you would get a _._ display for too low or a -.- display for too high.
If you want to troubleshoot this problem yourself, get an inexpensive digital multimeter. First check the brake wire on the truck for voltage and continuity. Also make sure the ground wire pin is good. Pull the brake drums off the trailer axles. Inspect all the wires. Use the multimeter to test for voltage and continuity. Check from the plug back to the brakes on both the brake wire and ground wire. Testing each individual brake while supplying voltage from the Prodigy may shed light on where a short or bad ground might be.
Otherwise, since it's a new trailer you could take it to a trailer or R.V. repair. Assuming there was a problem with how your trailer was wired or assembled, the dealer/manufacturer should be willing to rebate your expense.
This data comes with the Prodigy, but I'll post it here for everyone else to see and perhaps come up with the correct solution for the problem:
Display: SH
Situation: Flashes 2 times per second:
Probable Cause: Brake wire sees short during idle condition.
Display: o.c
Situation: Flashes for 15 seconds.
Probable Cause:
1. Trailer not connected to tow vehicle.
2. Trailer connected withe open circuit on brake line.
3. Trailer connector disconnected or corroded.
4. Loss of trailer brake magnet ground.
Display: o.L
Situation: Flashes 2 times per second.
Probable Cause: Prodigy "sees" an overload condition during operation.
Display: .c
Sitiation: Normal. Power to Prodigy with trailer connected.
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Postmaster
Joined: Apr 2001
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From: Baileyton, TN
Thank you for the replies, guys..
Mud Doc:
Thank you for your input. The truck I used to tow the problematic trailer with tows one of four other trailers regularly. The trailer also presented the same problem with a different truck. I therefore assume a trailer problem.
Horsepuller:
Thank you for the data relating to the Prodigy - I am all packed up for a move, so have no clue where the manual for the controller is.
The Prodigy is mounted ok.. so it is the trailer causing the problem. With it displaying both SH, and oc, I am assuming that an open cct, with occasional short is the problem - a loose wire perhaps. Thank you for the instructions on how to check for that.
I checked the wiring after I posted, and found it wrongly coded - the colors were wrongly connected to the plug, and to the trailer electricals. I rewired both, created a ground, and connected the 12v center, and managed to get the lights to operate without benefit of grounding through the hitch. This also made a more positive connection for the brakes.... but only when stationary. When moving, after I rewired it, the SH was much less frequent, the oc only very occasionally, and the oL only when braking - that aspect of the problem was unchanged - brake, it would display the overload.
I am assuming that I could disconnect one axle's brake wire, and try the trailer - if it operates correctly, I have located the zone to check. If it operates still wrongly, disconnect the other axle, reconnect the first and try again. If it operates ok, then again, I have located the problem. If it operates wrongly, I would assume the wiring to the axles to be suspect, and, rather than fish around with it, to find the problem, I would simply remove it, and replace with new.
Does that sound like a logical approach, or not?
Mud Doc:
Thank you for your input. The truck I used to tow the problematic trailer with tows one of four other trailers regularly. The trailer also presented the same problem with a different truck. I therefore assume a trailer problem.
Horsepuller:
Thank you for the data relating to the Prodigy - I am all packed up for a move, so have no clue where the manual for the controller is.
The Prodigy is mounted ok.. so it is the trailer causing the problem. With it displaying both SH, and oc, I am assuming that an open cct, with occasional short is the problem - a loose wire perhaps. Thank you for the instructions on how to check for that.
I checked the wiring after I posted, and found it wrongly coded - the colors were wrongly connected to the plug, and to the trailer electricals. I rewired both, created a ground, and connected the 12v center, and managed to get the lights to operate without benefit of grounding through the hitch. This also made a more positive connection for the brakes.... but only when stationary. When moving, after I rewired it, the SH was much less frequent, the oc only very occasionally, and the oL only when braking - that aspect of the problem was unchanged - brake, it would display the overload.
I am assuming that I could disconnect one axle's brake wire, and try the trailer - if it operates correctly, I have located the zone to check. If it operates still wrongly, disconnect the other axle, reconnect the first and try again. If it operates ok, then again, I have located the problem. If it operates wrongly, I would assume the wiring to the axles to be suspect, and, rather than fish around with it, to find the problem, I would simply remove it, and replace with new.
Does that sound like a logical approach, or not?
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Joined: Jul 2004
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From: Tri-Cities, WA
