08-01-2011, 07:03 AM
Hello again,
I introduced myself a little over a week ago. I found this site while looking for a wiring diagram. I was having issues with the left side marker lamps not working and not working well with the turn signal. Steady non flashing light with the lights on and intermittent operation with the lights off. I decided to replace the turn signal but the issue remained. Last night I found another resource online that will sell you a downloadable 483 page electrical book for the 1970 complete with colored wire diagrams for 14.95. http://www.mre-books.com/electric/1970_mustang.html Much of what is in the book I already had through the Original 1970 Shop Manuals, Chiltons and Haynes books. The nice part was some of the circuit extractions, the ability to enlarge and the color coding. It is a 120 MB download. Probably many of you already know this but I didn't. The right and left front turn signal housing which attaches to the bumper provides the ground for the respective side marker lights. I still can't find it in the wiring diagrams. But when I took voltage measurements at the pin connectors between the right and left side, they were the same. Even though the housing mounting screws were tight; years of corrosion created enough resistance for poor ground contact. When I physically put pressure on the housing against the bumper front and left side marker lights energized. I ended up drilling a new hole between the mount screws and added a small sheet metal screw to tie the metal together for better conductivity. Lights working normal now. Hope this helps. Best Regards.
Bill
I introduced myself a little over a week ago. I found this site while looking for a wiring diagram. I was having issues with the left side marker lamps not working and not working well with the turn signal. Steady non flashing light with the lights on and intermittent operation with the lights off. I decided to replace the turn signal but the issue remained. Last night I found another resource online that will sell you a downloadable 483 page electrical book for the 1970 complete with colored wire diagrams for 14.95. http://www.mre-books.com/electric/1970_mustang.html Much of what is in the book I already had through the Original 1970 Shop Manuals, Chiltons and Haynes books. The nice part was some of the circuit extractions, the ability to enlarge and the color coding. It is a 120 MB download. Probably many of you already know this but I didn't. The right and left front turn signal housing which attaches to the bumper provides the ground for the respective side marker lights. I still can't find it in the wiring diagrams. But when I took voltage measurements at the pin connectors between the right and left side, they were the same. Even though the housing mounting screws were tight; years of corrosion created enough resistance for poor ground contact. When I physically put pressure on the housing against the bumper front and left side marker lights energized. I ended up drilling a new hole between the mount screws and added a small sheet metal screw to tie the metal together for better conductivity. Lights working normal now. Hope this helps. Best Regards.
Bill