I am only getting 8 volts to the brakes. Have 12 volts at the blue wire in the pin connector box going to the rv. Somewhere the wiring changes from the blue wire in the connector box to the brakes. Anyone have any ideas.
Are you reading the same 8 volts at all four wheels?
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Jim in Memphis, Wife of 51 years is Brenda
2019 F450 6.7 Powerstroke
2018 Mobile Suites 40RSSA
2021 40' Jayco Eagle
2001 Road king w/matching Harley sidecar
2021 Yamaha X2 Wolverine 1000
I am only getting 8 volts to the brakes. Have 12 volts at the blue wire in the pin connector box going to the rv. Somewhere the wiring changes from the blue wire in the connector box to the brakes. Anyone have any ideas.
What make, model and year is your truck and trailer?
If I'm reading this correctly you are reading 12 v on the truck side and 8 v on the trailer side? If that's correct, then were you using the truck ground to check the truck and the trailer ground to check the trailer? If thats correct then I'd suspect an issue with the trailer ground.
Can you better describe where you are taking your voltage readings? Is the "pin connector box" the 7 way plug receptical or the wiring harness connector under the truck or ???
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Marshall
2012 Laredo 303 TG
2010 F250 LT Super Cab, long bed, 4X4, 6.4 Turbo Diesel
It's a 2006 2500HD Silverado and 2020 Cougar 353 SRX. I'm getting the 12 volts at the pin connector box which connects 7 way pig tail to the RV. 8 volts are at all 4 wheels. There has to be another connector in the trailer because the wires at the brakes are not the same wires at the pin connector box where I'm getting 12 volts.
You will most likely find that in your Pin box wire junction box the COMMON POSITIVE FEED wire to all four brake magnets is the PURPLE wire as shown in my image of my Alpine
The 12 volts is parallel fed to all four brake magnets
You will see the BLUE wire from the 7 way feed is tied into Purple wire in the junction box
Second image is general overview of the wires fed on the Trailer frame to lights, brakes,etc.. Note the color for brake magnets is Purple
I have the same as you except the purple wire is blue. It's not the same wire back at the brakes. There must be another junction box somewhere.
Chuck "typed purple wire" but in his photo it's marked "blue wire"...
The point is, from the trailer umbilical, the brake wire goes directly to that junction box. Check the crimp connection on the blue wire (in the junction box) for voltage. It should be the same as the truck blue wire voltage.
I'd suspect that either the blue wire crimp is faulty/corroded or the white wire (ground) from the brake circuit is not making good contact in that "multiwire crimp of all the white/ground wires".....
Apologize for all the questions, just trying to get as much info as possible. How are you energizing the brakes? With the truck controller or by pulling the breakaway pin? Obviously you're having brake issues can you elaborate what prompted 8ou to check the voltage?
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Marshall
2012 Laredo 303 TG
2010 F250 LT Super Cab, long bed, 4X4, 6.4 Turbo Diesel
Trailer brakes seemed awful soft compare to old trailer. I have since the posting cut all connections at the brakes and measured voltage at 12 volts coming thru the underbelly. Then connected one brake at a time each dropping the voltage 1 volt. The wires coming from the underbelly appear to be 16g, same size as the magnet wires and thru axle wires. It appears the wire running from the pin box is 14g and then spliced at both axles with 16g. I think the voltage drop is due to under sized wire.
There could be other issues regarding soft brakes, have you pulled the drums to inspect them? I had grease getting past my seals and covered the brakes, brakes were very soft also.
Lippert axels, at lease since 2017 have a defect causing the seals to prematurely fail and allowing grease to the brakes. There is actually a class action lawsuit regarding this problem.
There could be other issues regarding soft brakes, have you pulled the drums to inspect them? I had grease getting past my seals and covered the brakes, brakes were very soft also.
Lippert axels, at lease since 2017 have a defect causing the seals to prematurely fail and allowing grease to the brakes. There is actually a class action lawsuit regarding this problem.
Also if you've ever pumped grease into the EZ Lube zerks on the spindles the odds are very good the drums are full of grease.
I personally will never again pump a single drop of grease through that system. Actually replaced the zerks with it's so no one else would be tempted to pump grease into them.
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Full-timed 10+ years
Sold '13 Redwood FB
Traded '13 GMC Denali DRW D/A
Replacement undetermined
I beleive the wire size has been the same for maybe decades on thousands of trailer axles. I would say that's not an issue.
But I have a question for anyone who has checked. If you have a voltage lower than 12v at the wheels/brakes when connected. What's the voltage when you check with the brakes activated as in someone pushing the brake peddle down hard or the controller itself. I have in the past listened for the humming brake drums while the brakes are applied, never measured voltage.
The only braking problem I have had was the faulty ground on the RV E brake on the many RVs I owned.
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2013 24RKSWE (27ft TT) Cougar 1/2 ton series SOLD 10-2021
2013 Ford F350 4x4 CC 6.7 engine, 8 ft bed, 3.55 rear end, lariat package
Retired from Oregon State Police in 2011 than worked another 9.5 years as a small town traffic cop:
As of 05-2020, I am all done with 39 years total police work. No more uniforms for me.
I was getting 6v to 8 something when i was checking. I think it has to do with what you have your brake gain set to and how hard you brake. Ken what was that e brake ground problem you had. I may have the same thing going on. I get the message on the dash of trailer brake disconnect and the same massage when i pull the e brake pin out. I've been chasing this all week. Is it just where the unit mounts to the frame.
Trailer brakes seemed awful soft compare to old trailer. I have since the posting cut all connections at the brakes and measured voltage at 12 volts coming thru the underbelly. Then connected one brake at a time each dropping the voltage 1 volt. The wires coming from the underbelly appear to be 16g, same size as the magnet wires and thru axle wires. It appears the wire running from the pin box is 14g and then spliced at both axles with 16g. I think the voltage drop is due to under sized wire.
What's the commonality between the two trailers? Differences in weight, tires, brake adjustment, etc. will make a difference in how it "feels" and may require adjusting the controller. Did you check the brake shoe adjustments before tearing into the wires?
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Marshall
2012 Laredo 303 TG
2010 F250 LT Super Cab, long bed, 4X4, 6.4 Turbo Diesel
Also if you've ever pumped grease into the EZ Lube zerks on the spindles the odds are very good the drums are full of grease.
I personally will never again pump a single drop of grease through that system. Actually replaced the zerks with it's so no one else would be tempted to pump grease into them.
Yes, never pump grease to the bearings, they should be hand packed every 5-10,000 miles.
I was getting 6v to 8 something when i was checking. I think it has to do with what you have your brake gain set to and how hard you brake. Ken what was that e brake ground problem you had. I may have the same thing going on. I get the message on the dash of trailer brake disconnect and the same massage when i pull the e brake pin out. I've been chasing this all week. Is it just where the unit mounts to the frame.
On the newer trucks with factory brake controllers the voltage to the rv
brakes is proportional to speed & pedal pressure. You most likely will not get the full 12 volts sitting still touching the pedal or squeezing the manual lever.
If the rv brakes lock up once you pull the e brake pin they're probably ok, if not I'd start by adjusting the shoes.
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Full-timed 10+ years
Sold '13 Redwood FB
Traded '13 GMC Denali DRW D/A
Replacement undetermined
On the trailer that I had the emergency break away ground problem. I had an older truck without dash warnings. The trailer brakes would work fine for a brake to 2 than quit working and come back, finally they quit all together. I was pulling a friends trailer, he was following. We checked all the brake wires and connections we could and nothing was found wrong. We stopped at next city and got to a RV shop. RV guy was conducting tests, I was out shopping. Got back and it was fixed, he found the ground wire for the e brake broken away from it's ground screw. Under 20 bucks to fix, rv guy got a nice tip.
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2013 24RKSWE (27ft TT) Cougar 1/2 ton series SOLD 10-2021
2013 Ford F350 4x4 CC 6.7 engine, 8 ft bed, 3.55 rear end, lariat package
Retired from Oregon State Police in 2011 than worked another 9.5 years as a small town traffic cop:
As of 05-2020, I am all done with 39 years total police work. No more uniforms for me.
I think i got it down to a problem with the truck. Seems that when i use the 7 pin on the bumper i do not get the warning. Only when i use the plug in the bed i get it. I did find what i think was a loose connection on that plug but i have not road tested it yet. Gonna try tonight or tomorrow.
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