brake wiring

[Tractorat]

I just installed a PrimusIQ brake controller in my truck. Sometimes it looks like it is working correctly. But quite often it shows an overload condition. Im told that this means a magnet is going south on one of the trailer wheels. I was told that the way to troubleshoot the problem is to cut the wires to each magnet and pull the trailer to see if the problem goes away. When I cut the wires to the correct wheel, that will indicate that Ive found the culprit.

Here is my question. When I cut the wires to a particular magnet, should I cut both wires ? Or just one ? It seems that if I cut just one wire I will have opened the ckt and keep it from shorting. But the guy I talked to said I need to cut both wires.

Thanks

 

[B.G. Smith]

One wire should do the trick since the magnet is a wound coil with both leads coming out. You should be able to determine which magnet is bad by checking the resistance to each coil also but that will require you to expose both wires. Many of the trailers brakes wireing is run through the hollow axles and is a trouble spot for the wires to rub and short out. Good luck. bg

 

[Tractorat]

Thanks BG, I may just try the resistance checking method. Its a pia to hook up the truck, cut the wires, drive around for a while, repeat, then park the truck alongside the house again.

Thanks.

 

[SnoKing]

If the short is the wire to backing plate, then you need to cut both. Also the wires inside the axle tube suck big time after a lot of years on the road. Rewiring to a star configuration outside the axles with heavier wire is a really good upgrade to trailer brakes. SNOKING

 

[Tractorat]

Thanks Snoking. It turned out to be the wiring in both axles. I rewired outside the axles with heavier wire.

 

[SnoKing]

Brakes will most likely better than ever! Driven a new RAM lately????? SNOKING

 

[MLee]

This discussion was aired a few months ago and the heavier wire was mentioned #12 I believe across the outside of the axle. Now my question, does the wire to the magnet cause a choking effect on the magnet because its a #16 wire lighter, than the rewire of #12.

Snoking is the "star" pattern new or just your interpretation of a rewire and how so. Is it more effective? Mine is the standard wire (14) and a common ground for all wires. Just looking for improvement and the best it can be.
Thanks for input.

 

[SnoKing]

Long runs need heavier gauge wire. The short magnet pigtail is not that big of a deal, as it is just that short. The star configuration indicates have the wire runs to each brake is the same length, thus any voltage drop /current loss in the wiring will be the same to each brake, causing a uniform braking setup. SNOKING

 

[Tractorat]

Brakes dont seem to work a whole lot better (maybe a little). But I probably need to get them adjusted anyway. So Ill probably do that some time in the near future. At least my brake controller works now.

The star configuration indicates have the wire runs to each brake is the same length, thus any voltage drop /current loss in the wiring will be the same to each brake, causing a uniform braking setup. SNOKING

Makes sense. But that would mean running the left side wires down the left side of the trailer and the right side wires down the right side of the trailer and eliminating the wires running across the axles altogether. That would be an added benefit.

 

[SnoKing]

Well I have 2x2" cross tubes install between the spring hangers as part of my cracked frame repair, so it created a logical place run the wiring. SNOKING

Here is a picture of the cross tubes. This was before the rewiring. The main wire now goes to the center of the cross tube in the front of the picture and stars to the backing plates from there.

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