I have an intriguing issue...
I recently removed an aftermarket Electric Trailer Brake Unit (ETBU) from a friends car (97 Australian Ford Falcon). This was an accessory which I had fitted about 2 years before they bought the car from me.
They later indicated a problem since I had taken out the ETBU.
Seems that when the lights are on & you have your foot on the brakes, you cannot turn off the engine. Take your foot off the brakes, or sw off the lights & the engine will stop.
They told me that also the "Cruise control won't work". I determined that it will actually work, but not when the lights are on.
If you have the ignition on, the lights off, put your foot on the brakes, the dash lights come on.
I inspected the wiring where I had removed the ETBU & found no evidence of any problem.
(The unit has 4 wires, two wires are spliced onto the brake switch wire, and a +12V power wire which is live only when the ignition is on, the other two are a ground or earth to the chassis, & the last one is a wire which is run all the way to the trailer plug at the towbar, which supplies power to the electric brakes on the trailer). The two wires which were spliced into are OK, not shorted, nor broken etc. The earth wire is removed & the brake power wire is taped & coiled up & tied out of harms way under the dash. I am suspecting this is a coincidence with the ETBU removal, but still is a bit of a puzzle.
I also discovered that the brake lights do not work (but have proven that the sw on the brake pedal is operating).
When I disconnected the wiring loom going to the RH rear brake light, the symptoms seem to dissappear. My next thought is that possibly the brake light lamp on RHS has shorted internally so that the tail light terminal is linked to the brake lamp terminal? This is a dual filament globe with 3 terminals, a common ground, a brake lamp & a tail lamp. But I realise unplugging the right lamp assembly may simply be interrupting the link from a problem elsewhare.
I can reason out the symptoms for the lights & cruise control issues, but can't work out why the engine won't turn off.
I have yet to remove & replace the lamps, as they were not easily accessible & I only had limited time when I first went to investigate.
Any thoughts, folks?
OldTech
1997 Ford Falcon EL - Wiring Problem or Short Circuit?
Re: Wiring problem or s/c in 97 Ford Falcon EL
