Troubleshooting A Battery Disconnect That Keeps Allowing Power Through
Updated 02/17/2026 | Published 06/11/2024
Question:
I recently purchased a 2008 Jeep Wrangler and moved my Roadmaster Invisibrake over. Previous vehicle was a Jeep Liberty. The owner had an older version or the Roadmaster automatic battery disconnect that he sent with the Jeep. The large battery cables were included but all of the smaller wires were missing. I ordered a replacement switch from your team and build the ground wire, fused wire coming off the large terminal and wire coming off small post on solenoid. I hooked everything up and the switch kills the power as expected, however, 10 seconds later the solenoid energizes and powers back up. I have checked all the wiring so I am assuming the the unit may be bad. Is there a way to test?
asked by: Tom Y
Expert Reply:
Hey Tom,
If the battery disconnect is allowing power through from the battery when turned off then we know the solenoid is bad. There really isn't more that you can test besides turning it of and checking the output cable to see if it reads any voltage. Roadmaster has very specific rules about adjusting the cables because the posts they're on can't handle tension and will spin and destroy the inner workings of the disconnect. The previous owner likely didn't follow those rules and damaged the solenoid so now you're looking at a complete replacement with part # RM-766.
Product Page this Question was Asked From
Roadmaster Battery Disconnect for Towed Vehicle w/ Flat Tow Brake System - Gas Only
- Accessories and Parts
- Flat Tow Wiring Harness
- Battery Disconnect
- Roadmaster
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Jenny N.
2/17/2026
Hey Tom, how did things go after you replaced the solenoid on your Jeep Wrangler’s battery disconnect? Your update could make it easier for the next person troubleshooting a similar issue.