find trailer brake wire

[grsthegreat]

I found it! Thanks for the suggestions - they forced me to look at things again. I had already done the 9v battery trace to no avail. That was because I tested the wrong pins! (dope slap to self). I connected to the pins at 5 and 7 o'clock (bottom two) and came up with nothing, duh!. I had inverted my measurement positions. I changed to pins at 11 and 1 o'clock (top two) and, voila, I had voltage on the blue wire under the hood! Home free.
Thanks, again.

glad to hear it all worked out

 

[Dmace]

I found it! Thanks for the suggestions - they forced me to look at things again. I had already done the 9v battery trace to no avail. That was because I tested the wrong pins! (dope slap to self). I connected to the pins at 5 and 7 o'clock (bottom two) and came up with nothing, duh!. I had inverted my measurement positions. I changed to pins at 11 and 1 o'clock (top two) and, voila, I had voltage on the blue wire under the hood! Home free.
Thanks, again.

I should have mentioned, it's usually the blue wire.