Prodigy P3 Overload Warning

[RK_Hauler]

I am getting an intermittent overload warning on my P3 controller that just started about 500 miles ago during our last trip. I would like to get it resolved to get us back and then R&R the whole system.

The warning only happens after I come to a complete stop, then disappears when I let off and/or pump the brake. It doesn't show up until I come to a complete stop again. No warning when in the process of stopping so haven't lost brakes when stopping.

I suspect it is a magnet or a bad wire inside the drum and would like to test to see which one it is without removing drums. Wondering if anyone has advice on a good/best way to do this sort of test?

Thanks in advance,

Greg

[Bigbird65]

OK with coaching from my friends on 2 different web sites I put the DRYCONN water proof connectors on. Here are a couple of photos. I had to use 2 different sizes on the left front brake.

[Bigbird65]

Test drive today and ZERO OVERLOAD ALARMS. Drove 15 miles in town and on the highway and not one single alarm came in. Did lots of braking to check it out. My DW said the brakes seemed smoother to her. I agree. Needless to say, I'm a happy camper.

[Bigbird65]

time2roll wrote:
You can get waterproof wire nuts in the landscape department.
At least turn them up to avoid trapping water.

I would zip-tie around the axle before those stickers are in the wind.

Since I posted the photos I had the same idea as you and turned the wire nuts up. Before I put the square zip-tie anchors on the axle housings I cleaned each spot with alcohol. I then ran a bead of Goop around each anchor. I feel certain they won't come off.

[time2roll]

You can get waterproof wire nuts in the landscape department.
At least turn them up to avoid trapping water.

I would zip-tie around the axle before those stickers are in the wind.

[BruceMc]

Speaking of magnets... when we first acquired our 18' flatbed, the wiring and brakes were in dismal shape. I used it for a few years before I decided to rebuild the brakes & wiring prior to hauling a heavy load (a '57 chevy 2dr post from Boise to the Portland area); it had brakes on the front axle but none on the rear.

One puck was worn completely through to the windings and the other one was not far behind. I replaced the pucks and shoes, then repacked the wheel bearings & installed new seals. What a difference! I'll never run a medium trailer w/o brakes again. We also have a couple light trailers w/o brakes & we do fine with those.

[Bigbird65]

BruceMc wrote:
Looking good!

On our fiver, I struggled with uneven braking. With decent trailer brake sensitivity set, the left front tire would consistently lock up followed by the left rear. I don't thing the right ones ever locked up.

I pulled all the factory wiring (connected with scotchlocks, if I recall) out & replaced it with highly flexible rubber sheathed extension cord cable. I ran 10 gauge to a point near the axles, 2 EQUAL lengths of 12 gauge to the center of the axles. At that point, I ran EQUAL lengths of 14 gauge to each brake.
All connections were soldered & weather shielded; the cord was attached to the tops of the axles with a spot of adhesive and electrical tape. No connectors were used except the crappy 7 pin on the pin box.

It worked very well. I never had lockup issues; all 4 wheels braked at the same rate. It became a pleasure to tow ... then I traded it in on our first Class C. I hope the future owners enjoyed it as well as we did!

Bruce, very glad to hear that your rewiring job was so successful. If I should have any corrosion problems then I will go the solder route that you did. I think the only thing that will cause my intermittent overload will have to do with the magnets because everything else is clear.

[BruceMc]

Looking good!

On our fiver, I struggled with uneven braking. With decent trailer brake sensitivity set, the left front tire would consistently lock up followed by the left rear. I don't thing the right ones ever locked up.

I pulled all the factory wiring (connected with scotchlocks, if I recall) out & replaced it with highly flexible rubber sheathed extension cord cable. I ran 10 gauge to a point near the axles, 2 EQUAL lengths of 12 gauge to the center of the axles. At that point, I ran EQUAL lengths of 14 gauge to each brake.
All connections were soldered & weather shielded; the cord was attached to the tops of the axles with a spot of adhesive and electrical tape. No connectors were used except the crappy 7 pin on the pin box.

It worked very well. I never had lockup issues; all 4 wheels braked at the same rate. It became a pleasure to tow ... then I traded it in on our first Class C. I hope the future owners enjoyed it as well as we did!

[Bigbird65]

PUCampin wrote:
In my case, my OL, Short, Not Connected, error codes were caused by the wires inside the drums being too long. In 2 of the 4 wheels, the drum rubbed through and the wire made intermittent contact with the rotating drum causing all kinds of issues. If you have not removed your drums and checked this, do so.

I have had the drums off several times and never found the wires to be too long. They feed through an insulator on the brake back plate. There may be potential for the wires to short to the back plate or the brake shoe lever arm. Anyway I can easily, after rewiring, take a brake magnet out of service for testing purposes if I am still having overload issues.

[Bigbird65]

RCMAN46 wrote:


Two things.

First you need to replace the wire nuts with waterproof crimps.

Wire nuts will allow the connections to corrode and will not be able to handle the vibration they will be exposed to.

Second the P3 has a diagonistic feature that will give the current drawn by the brakes.

I have found the current will be very close to 1 amp per volt applied.

This correlates close to the resistance you measured.

I check the voltage applied and current drawn before every trip with the manual lever on my P3.

I felt sure that this comment about the wire nuts would come up. I have used wire nuts like these on trailers for years and have not come across a corrosion problem. However, I will keep a close eye on them. I do use the P3 diagnostic information. FYI, here is the reading that I got on each magnet measured with a Fluke 79 meter on the 40 ohm scale. LF 3.4 ohm, LR 3.9 ohm, RF 3.5 ohm, and RR 3.3 ohm. Thanks for the reply.

[PUCampin]

In my case, my OL, Short, Not Connected, error codes were caused by the wires inside the drums being too long. In 2 of the 4 wheels, the drum rubbed through and the wire made intermittent contact with the rotating drum causing all kinds of issues. If you have not removed your drums and checked this, do so.

[RCMAN46]

Bigbird65 wrote:
The wiring has been completed. No telling how long I have been running with only 75% braking. I found that on the right front one of the magnet wires was out of the original factory crimped connection. Before I started, measuring with my Fluke meter, the brakes measured 1.5 ohms at the trailer connector. After the rewire the measurement is 1.1 ohms. It will now be really easy to isolate a magnet. Hope to take it out for a spin tomorrow to see if I helped the overload alarm.

Two things.

First you need to replace the wire nuts with waterproof crimps.

Wire nuts will allow the connections to corrode and will not be able to handle the vibration they will be exposed to.

Second the P3 has a diagonistic feature that will give the current drawn by the brakes.

I have found the current will be very close to 1 amp per volt applied.

This correlates close to the resistance you measured.

I check the voltage applied and current drawn before every trip with the manual lever on my P3.

[Bigbird65]

The wiring has been completed. No telling how long I have been running with only 75% braking. I found that on the right front one of the magnet wires was out of the original factory crimped connection. Before I started, measuring with my Fluke meter, the brakes measured 1.5 ohms at the trailer connector. After the rewire the measurement is 1.1 ohms. It will now be really easy to isolate a magnet. Hope to take it out for a spin tomorrow to see if I helped the overload alarm.

[Bigbird65]

Greg I found out that a disc brake kit would cost about $1200 with me doing the work. I would really enjoy installing them because I'm a do-it-yourselfer. However, that is above my brake budget. Even if I replace all 4 magnets it is only about $100.

This afternoon I made a sketch of my proposed rewire. Should get on it pretty soon.

Ken

[RK_Hauler]

Bigbird - I had a spare magnet that was in decent shape but decided not to mess with it as I only had a thousand miles or so to get home. If I were to stick with the electric brakes I would have needed all new backing plates and drums. Once the magnet surface on the drum is grooved they don't work very well.

Disc brakes are electric over hydraulic. 3x the cost of electrics, but I haven't heard from anyone who has them that says they aren't worth it. Lots of info and sources on the internet.