No Trailer Brakes when Stepping on Brake Pedal on a 1998 Land Rover Range Rover

Question:

I have installed on a 1998 Range Rover. I connected it to the middle wire on the brake pedal There are 3 wire This is the one N/O switch, that when I push the brake pedal I receive a 12v+ supply to this wire. If I depress the manual brake switch it applies the brakes and on my multi meter to volts increase from about 0.4 to 12.5 volts on the red wire Tested at the trailer plug join. But when I depress the foot brake nothing happens and the volts do not change from .4 v. \ The Range Rover has two switches at the foot brake one is N/C Has two wiresand s volts off when brake pressed and the N/O switch Has three wires but only one of them gets a 12V supply when pedal pushed.

asked by: Rikki G

Expert Reply:

The problem you are having is definitely on the red wire. If you use the brake pedal and get no trailer braking action then that indicates the connection on the red wire is the issue. Make sure it is securely attached to the brake switch wire.

Also, make sure that you have the right wire. You would want to test all of the wires that you can find at the brake switch. The wire needs to have power only when the brake pedal is pressed. If it has power with the headlights or turn signals on it is not the correct wire.

If none of the brake switch wires seem to work then you might be able to get the signal elsewhere. Check the owners manual for all of the fuse locations. If there is one for the CHMSL (center high mount stop lamp) only, no other function other than that, you can tap into that circuit. Any dedicated brake light only circuit will work.

expert reply by: Michael H