(800) 853-2651
SHOP NOW

trailer brakes redux

Steve in VA

Steve in VA

Well-known Member
Location
Natural Bridge Virginia
Buddy has a Suburban. Purchased a brake controller. When connected to my trailer, it sets the brakes from the get go. I tested the truck connector with my VOM and found voltage to the brakes at all times, but only 4-5 volts. When the brake pedal is pressed, the brake contact reads 12v. When not depressing the pedal, the brake connector still shows voltage. I'm not too proud to say I don't understand it. Solution? Thanks in advance.
 
DIsconnect the leads to the connector at the controller. Test the voltage at that terminal to see if it has the voltage if so, it may (guessing) maynot be zeroed internally. If not, there is voltage getting into the wire between the controller and the connector. possibly cross wired with brakelights, or a bad ground in the brake light circuit. (guessing). Jim
 
Sounds like a bad controller to me. Even a crossed wire in the plug would give 12v even if it only produce a small amerage. Disconnect and check the brake wire right at the controller to make sure nothing is back feeding from the truck.
 
You'll have better success checking it with a test light.

The volt meter is picking up the "sensing circuit", the small voltage, low amp signal that feeds back to the controller letting it know the circuit is complete (the LED that comes on when connected) and not shorted to ground.

Connect the test light to the terminal that makes the LED on the controller light. The test light should be off. Then have an assistant push the manual slide. The test light should slowly come up to power. If it does, the controller is working.
 
A test light does not always work since they don't have enough resistance to activate some controllers. So if the test light does not light it may or may not mean you have a problem. If it lights at all with the brakes not activated then there is a problem for sure.
 
You must log in or register to reply here.

Similar threads

S
1980 JD 410 D No brakes.
Replies
4
Views
212
snogo
S
D
Trailer taillight wiring, is there a standard method?
Replies
15
Views
1K
Brown David
Brown David
G
Trailer winch battery wiring
Replies
16
Views
2K
Jim.ME
J
super99
Trailer update
Replies
15
Views
2K
Mike Henry
M
super99
Trailer Brakes
Replies
12
Views
2K
Dennis Minn
D
Tractor Parts Tractor Manuals

We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today.

Copyright © 1997-2024 Yesterday's Tractor Co.

All Rights Reserved. Reproduction of any part of this website, including design and content, without written permission is strictly prohibited. Trade Marks and Trade Names contained and used in this Website are those of others, and are used in this Website in a descriptive sense to refer to the products of others. Use of this Web site constitutes acceptance of our User Agreement and Privacy Policy TRADEMARK DISCLAIMER: Tradenames and Trademarks referred to within Yesterday's Tractor Co. products and within the Yesterday's Tractor Co. websites are the property of their respective trademark holders. None of these trademark holders are affiliated with Yesterday's Tractor Co., our products, or our website nor are we sponsored by them. John Deere and its logos are the registered trademarks of the John Deere Corporation. Agco, Agco Allis, White, Massey Ferguson and their logos are the registered trademarks of AGCO Corporation. Case, Case-IH, Farmall, International Harvester, New Holland and their logos are registered trademarks of CNH Global N.V.

Yesterday's Tractors - Antique Tractor Headquarters
Website Accessibility Policy

Back
Top