When Will Digital Display on Reese Brake Controller Illuminate

Question:

On the Reese 74643 brake controller do I need the trailer connected to get the digital readout to display on brake controller? If so why does the trailer have to be connected? I understand I should see a dot when brakevpedal is pushed will I also see digital display with trailer not connected? Thank you for help

asked by: Pat

Expert Reply:

I was not able to confirm with Reese the part number 74643 you provided for your brake controller, but I believe it was for an old Brakeman controller. The Draw-Tite Activator # 5504 that you referenced, which is a time-delayed type controller, will display a blank screen under two circumstances.

A blank screen when the trailer is NOT connected indicates that either the unit is not getting 12V power, the ground is bad, the black (power) and white (ground) wire connections were reversed, or that the circuit breaker in the power feed is blown.

A blank screen when the trailer IS connected indicates that the trailer connector is mis-wired.

The linked instructions for the Activator II are linked for your reference.

Trailer wiring does often have certain conventions for wire colors and connector pin out, but the wiring in a trailer can vary from the common configurations. If a trailer has been rewired it may have been set up for a specific non-standard circuit arrangement.

Most likely the issue is in the wiring for the controller. If the Dakota did not come with a factory 7-way then the controller installation will have to had been a hard-wire type using an install kit like our # ETBC7. If the truck came with a factory 7-way then the installation could use a quick-connect wiring adapter # 3020-P to plug into the port under the dash. It is certainly possible that such an adapter could be mis-wired but this is quite rare.

Three linked articles will give you guidance for troubleshooting your installation and should help you find the issue.