I am trying to hook up a reverse light circuit on a project vehicle I'm working on. The vehicle has a resistor pack inside the transmission which changes the resistance through a signal wire to the speedometer ECU depending on which gear you are in, the ECU uses these signals to light up the different indicators on the dash telling you which gear you are in. The readings are as follows:
Park 24 ohms
Reverse 75 ohms
Neutral 160 ohms
Low 300 ohms
High 620 ohms
What I want to do is use the signal for reverse, 75 ohms, to activate a 12 volt relay for reverse lights but the relay can only be activated then it sees 75 ohms, not more and not less. Is this possible?? Thank you