All trailers come with an Anti-Lock Braking System (ABS) which helps to maintain steering control and avoid skidding, jack-knifing, and trailer swing out during emergency or slippery roads.
The system comes with an indicator light on the trailer dashboard which comes on and off when the trailer is started. If the ABS light stays on or comes on when the brakes are applied, it means that something is wrong with the ABS system that should be fixed immediately.
If your trailer ABS light comes on whenever you apply the brakes, you may have a trailer-blown ABS fuse that caused the malfunction. Replacing the fuse will stop the light from coming on.
Why Does Trailer ABS Light Comes On When Brakes Applied?
The reasons why the trailer abs light comes on when brakes are applied are:
1. Blown Trailer ABS Fuse
The reason why your trailer ABS light comes on anytime you apply brakes is because of a blown trailer ABS fuse.
If the trailer ABS fuse goes bad or malfunctioning, it will cause your abs light to always come on anytime you apply your brakes and go away after a few minutes.
Before calling anyone to start fixing what is not there, replace the abs fuse on your trailer first, the problem should go away.
However, if after replacing the trailer the fuse and the problem continues, then, something else is wrong with the trailer’s ABS system.
Some trailer owners say it’s a good thing, while some say it’s not a good thing. If the problem was not there and suddenly started, then it’s obvious that something is wrong with the abs fuse.
The only time the ABS light is permitted to come on and go off is when you just started the trailer or when you turn the trailer on ignition.
If after starting the vehicle, the ABS light comes on and stays on while the truck is in use, or comes on when the brakes are applied, then, something is obviously wrong with the truck’s ABS system.
2. Bad Wiring
If after replacing the ABS fuse the problem continues, then, the wiring could be messed up. Your trailer abs should have constant power throughout the 7-way, therefore, if the reverse is the case, it can cause the abs light to come on when the brakes are applied.
However, it’s important to note that not all trailers ABS are equipped with constant power to the blue wire circuit of the trailer plug. Old model trailers made in the 90s may have it while some may not. The type of trailer you drive determines the functionality of the ABS system.
Therefore, if your trailer ABS Light has never come on anytime you apply brakes and suddenly start it, something is wrong with the system and the culprit should be the ABS fuse.
On the other hand, if the trailer abs light has been like that since you started the trailer, then it’s a good thing as long as the light comes on and off within seconds. However, if won’t hurt if you replace the abs fuse to be sure you’re not having a fuse problem.
Well, the good news is, if peradventure your trailer abs did not come with the ability to supply constant power to the blue wire circuit, you can have it rewired to do so. It will only cost you a small amount of money.
3. Improper Wheel Sensor Positioning
Another reason why your abs light comes on whenever brakes are applied can be traced to improper wheel sensor positioning especially when the trailer is in motion.
If you’re driving the trailer and the light comes on anytime you brake, the wheel speed sensor may have been installed in a way that it shifts when the brakes are applier, hence why the light is on.
The ABS system has always been delicate and sensitive in nature. You should therefore check the wheel speed sensor to be sure it’s properly installed.
4. Loose Terminal Connections
If you have loose terminal connections, it may cause the ABS light to appear anytime you apply the brake. Check for loose terminal connections and have them tightened properly.
When Should the ABS Light Come On in a Trailer?
The ABS light should come on in a trailer only when the trailer has just started and should go off within seconds.
The trailer ECU is designed in the sense that when the trailer is first started, it will run a self-diagnostic check on the car, while this is happening, the lights will come on the dashboard.
These lights should however go off when the self-diagnostics are complete. If the ABS light continues to be on afterward, then something is wrong with the ABS system.
The only exception to this is if your trailer was manufactured red before 1990 and if it is not equipped with constant power to the blue wire circuit.
Can I Drive With the ABS Trailer Light On?
No, you should not drive with the ABS trailer light on to avoid violating any law. Driving with an ABS trailer light is a violation of regulation especially if you are apprehended by law enforcement agencies in a traffic stop, you will be ticketed or fined.
Conclusion
Some trailers are manufactured in a way that the abs light comes on when the brakes are applied while some do not. If you don’t usually see the ABS light come on anytime you use the brakes, then it’s obvious that something is wrong with the trailer ABS system.
The first place you should check is the fuse. It’s better to check and replace the trailer abs fuse anytime you start seeing the abs light coming on in an unusual way.
