I had an interesting thing happen today. Driving around in my 86 SE 2.8, I noticed that the stereo cut out when I hit the brakes, every time. I tried a few other electrical items (turn signals, headlights) and the same thing happened. Now, it's not a stock stereo, and I did the installation, so I know it was done right (not bragging, just a big fan of soldered connections, proper connectors, heat shrinking and taking my time).
I noticed that all of the electrical items in the car were behaving slower or dimmer than before, plus the strange stereo behaviour, so I started to worry that my alternator was gone and the battery was running down. By this time, the turn signals were so slow, if they came on at all. I had a quick stop and checked to make sure that I hadn't thrown my alternator/water pump belt; it was fine.
Worried about shutting the engine off before getting home, I kept the car at about 40mph, and turned the engine off, then tried the starter (if the battery was dead, there wouldn't be enough to crank it over and I had enough momentum to get it started again by popping the clutch). Lots of juice, the car started right away.
I got home ok, and just had a chance to test a few things: battery with engine off measure 13.5 V. When the engine's running, there's 14.8 V at the terminals, so the charging system and battery's fine. Now, this was in the dark (I was using a flash light) and I must have brushed something 'cause I saw the final remains of a ground wire glow yellow and burn out. There was a green wire, about 18 guage, that came from the terminal block beside the battery and to a ground point on the engine.
I turned off the engine, replaced the wire, cleaned up the ground point and everything seems mostly fine. I say mostly, because when the headlights are on, the stereo on, and I flip the heater blower to high, the stereo still powers off then back on again.
Anyway, to make a long post short (sorry, too late, I know) I can't seem to remember ever seeing a ground strap from the engine/transmission to the firewall or other frame member like every other car I've owned. I didn't see mention of it in my Haynes manual (not that that means anything), but began to wonder if all the return current for the accessories was returning through that skinny little ground wire. I wouldn't be surprised if one of the previous owners removed it at some point and never put it back, as the car was a basket case when I got it (that's a story for another post).
So can anyone tell me if I'm on the right track and if so, where would I look to see if my tempermental little car is missing a ground strap?