Hi folks,

I am trying to replace this circuit board by reverse engineering where the wires are going. I worked out the 3 out of the 4 wires. But this blue wire, I am not sure what the purpose of it is.

I tried to use a multimeter and it gets 0.69v in some cases and 12v in other. It seems to be on same route as the RF antennae?? If that's the case why it is needed? If it's just for power, why couldn't it get it from the positive red wire that is already on the board.

Does anyone know?

 

Isn't it connected to the GND plane on the PCCT?
If so it may be the power return for a PWR antenna?
In that case you could read 12v when the circuit is 'OFF' and the return is open !

 

Isn't it connected to the GND plane on the PCCT?
If so it may be the power return for a PWR antenna?
In that case you could read 12v when the circuit is 'OFF' and the return is open !

I think you might be right about the power return. Although I don't understand the logic of that is because I would have thought the negative wire is how it "returns".

So if I have a circuit board like this (image attached) then where would the power return wire go? 12v negative?

 

Is there any way you can see the connection at the other end? At the antenna itself.
For the board, a little reverse engineering on it would help, usually not a lot to them.

 

Is there any way you can see the connection at the other end? At the antenna itself.
For the board, a little reverse engineering on it would help, usually not a lot to them.

I can't see fully where the blue wire actually goes as it's encased in the wiring harness. But it is attached to a power source plug which only has the positive and negative terminal to get a 12v source. And the other plug is just a three pin connector negative, positive and a signal wire. As mentioned in my first post, these three wires are already accounted for on the board. Hence my confusion with this dangling blue wire.

I took several more photos perhaps that can better illustrate.