Phil said:
> I own a 69mgcgt with a electrical problem. The car was stripped down,
> painted, engine brakes, suspension, and floor pans renewed. If I want to start
> it I have to attach an accessory ground from the battery to the back bolt
> holding the starter to the engine.
I've heard this one before, with the accompanying frustration level. The
starter grounds by contact with the engine backing plate. If your paint job was
too good, there's no metal to metal contact. Remove the starter and scrape off
the paint where it touches the backing plate. Hopefully, this will fix your
problem.
> If I remove a
> double green lead from the near side of the lower fuse, it doesn't blow.
I assume that you're saying that the fuse does blow if this wire is connected.
With the battery disconnected, check to see if this wire is grounded by using an
ohm meter connected to the wire and the chassis. If there are 0 ohms, the wire
is shorted to ground. If none of the exposed parts of the wire are obviously
grounded, the insulation could be melted inside the harness sheathing and the
wire is grounding through another wire. The way to find this is to disconnect
the ends of all of the wires near this one and check with the ohm meter to see
if they are connected. 0 ohms means they're connected and infinite ohms means
they're not.
If you have melted wires, it is possible to isolate and replace the offending
wires without replacing the harness. Aside from finding your immediate
problems, it's also a good idea to clean all of the grounds on the car.
To find the battery drain on your 74B, connect a voltmeter in line with the
battery. To do this, disconnect a battery cable and hook one clip of the
voltmeter to the cable and the other to the naked battery terminal. Make sure
all electrical consumers are off (doors shut, radio off, ignition off, etc.).
With this setup, electrical consumers won't work (e.g. lights won't shine) but
they draw current. If the voltmeter shows any voltage, this is your draw.
Disconnect electrical systems one by one until the voltmeter shows 0 volts.
When this happens, you've found your draw. Remove components from the bad
system one by one to find the culprit.
Don't give up on these cars! All problems have a cause that can be found and
fixed, usually fairly cheaply. If these suggestions and others' don't help, ask
again.
Good luck!
Denise Thorpe
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