Troubleshooting A Non-Functioning Indicator Light With A Demco Stay-IN-Play Duo On A Ford Maverick

Updated 07/18/2024 | Published 07/14/2024

Products Featured in This Question

Demco Wireless Coachlink Braking Monitor for Flat Tow Brake Systems

(104)

$285.00

Demco Stay-IN-Play Duo Flat Tow Brake System for RVs w/ Hydraulic Brakes - Proportional

(791)

$1245.50

Question:

Brake indicator light not working correctly. I have the Duo Stay and Play installed on a Ford Maverick. It functions correctly, applies Mav brakes when it should, But the indicator light on the back of the Mav mirror only lights when the coach headlight/markers/tail light switch is not on. With the lights on, the Mav still brakes correctly, but the indicator light does not come on. Same when I test the system by pulling the breakaway switch. Actuator depresses the Mav brake pedal whether coach lights are on or off. But the indicator light does not come on if the coach tail lights are on.

asked by: Michael D

Expert Reply:

Hi Michael,

The indicator light for your Demco Stay-IN-Play Duo # SM99251 needs to be tapped into the cold side of the brake light switch on your Maverick. This wire should be purple/white and only receive power when the brake pedal is being depressed. The indicator light should only be getting power when the brake pedal is depressed so you likely have the light wired incorrectly since it's activating when the running lights are on in the coach.

expert reply by: Kevin C

Stay-IN-Play Duo Wiring Diagram
(click to enlarge)

Michael D.

7/15/2024

Please re-read my question. The indicator does NOT light when coach running lights are on.

Kevin C.

7/18/2024

@MichaelD My bad, either way though something isn't wired correctly for this to operate how it is. Do you have a brake lite relay installed on your Maverick? When you ran the ground for the light did you run it to the chassis or the operating unit ground?

Michaeld

7/18/2024

@KevinC Thanx. I paid a shop to install it. Brake relay was installed. Where should the red and black wires from the light go? I'll get my son to crawl in there and look. I'm thinking red to blue form relay, and black to black from Demco switch box. Correct?

Kevin C.

7/18/2024

@Michaeld I've attached a short video below for the brake lite relay kit # RM-88400 that Ryan made that will show you how it's supposed to be installed in your Maverick. As for the indicator light the black wire must be tied to the black wire from the operating unit. This makes it so when the system is off while you're driving the Maverick the indicator light won't be flashing in your face when you step on the brake pedal. When you get to splicing into the brake light switch wire (purple and white wire) you'll have a blue and a black. The black wire is your output running to the tail lights. The blue wire is your signal wire looking for the brake pedal to be depressed for the signal to come through. Is the red wire from the indicator light tapped into blue or black wire or is it spliced in somewhere else for power? The brake lite relay kit taps into the running lights coming from the motorhome with the red wire so it's likely that the relay is wired incorrectly causing the issue only when the lights on the motorhome are on.

Helpful Links

tv-install-roadmaster-brake-lite-relay-kit-for-towed-vehicles-2023-ford-maverick-rm-88400.aspx