[Mgs] 80B, melted white-green wire from ignition switch

[Steve Shoyer]

Thanks to everyone who replied to my question.  I think I understand 
what probably happened.  I think the bullet connection between the 
white-green feed to the radio and the radio's wiring harness (which had 
an inline fuse) must have loosened and allowed the bare connector to 
short to ground, possibly on the heater control cable. When I removed 
the radio, there was no longer continuity between the white-green 
connector coming from the ignition switch and ground.  I replaced the 
ignition switch with a new aftermarket one, and I also replaced the 
radio.  The one that I had been using seemed fine, but it had a CD 
player so it was about 6" deep.  I picked up a new one without a CD 
player (a Jensen unit with Bluetooth for $36) that's less than 2" deep, 
so there's a lot more room behind the radio and it should be less likely 
to cause strain on the wiring.  This radio uses the same style of wiring 
harness as my old one so it was an easy swap.  Nothing melted when I 
tried the new switch and radio, so I think I'm good now.  I might try to 
use a zip-tie to hold the radio wiring in place and reduce the 
possibility of pulling the power connection apart.  I put in a 5A fuse 
for the switched power rather than the 10A fuse that came with the 
radio, hoping that it would blow quickly if there was a short somewhere 
in the circuit that I didn't see.

--Steve (1980 MGB)