First off, let me define a few things...

Trace: The copper layer on a circuit board that carries current and voltage.
Through Hole: On a two sided circuit board a through hole connects the bottom layer to the top layer or vise versa.

Cold Solder Joint: You didnt heat the part to 400*F and melted the solder on a part less than 400*F. You heat the part, not the solder!

This is a write up on how to fix your headlight switch. I think we are all familiar with that burning smell that eventually takes out the headlight harness and connector. This can be easily avoided. If you are having some issues with the headlight switch BUT do not have a melted harness yet, this will fix it. You DO need to do the headlight switch mod for this to work.

Link: https://www.rx7club.com/2nd-gen-arch...urnout-164931/

 

Oh no! the W/G has fried the board, lets fix it!

 

The best way to do this is to grab some fine wire and put it through the hole, and then solder the snot out of it. After you have done that, connect that wire with the W/G through hole joint because the circuit is cooked.

The engineering fail behind all of this is because they gave lots of copper for the front side and back side of this circuit but this trough hole connection is a bottleneck. It is the first place to burn. In the above I over soldered because the copper pads where toast. The copper wire is nice and wicked with solder but I added a little more to support the pad that is now gone.

 

double post, I blame my wife

 

Styx, can you remove the double post?