Steve Shoyer wrote:
>
> I bought a 1980 MGB a couple of months ago. It's gone through a number of
> modifications (Weber DGV, manual choke, emissions equipment removal, etc.)
> which will take some time to figure out, but for now I'm trying to make
> sense of the wiring.
>
> Can someone tell me what the connections to the fuse box are supposed to
> look like? Knowing the colors of the wires that are supposed to be
> connected to the terminals on either side would be great (knowing the
> circuits each wire runs would be an added bonus). I've spent some time
> with the Haynes and Bentley manuals and I've found a couple of differences
> between what "should" be there and what I've got, but I'm far from an
> expert, so I'd like to get a good starting reference.
If you've got the Haynes and Bentley you should have the wire colours on the
fuses.
> Also, any guesses on these problems?
>
> - The battery is being drained by something on the "always on" fuse
> (bottom). I traced it to one of the circuits connected to a purple wire at
> the fuse box, but not the one that controls the horn or interior light.
> Pulling the fuse between drives lets me start the car without jumper cables
> (usually), but any ideas what else could be doing it?
Roadster boot light? Clock? Warning buzzer?
> - The overdrive doesn't engage. It worked when I got the car.
Use a test lamp to check voltages at the switch and solenoid. Between these
two
there is a gearbox inhibitor switch that is only closed when the gearbox is in
third or fourth. If this switch is faulty don't be tempted to short it out.
If
you happen to go into reverse with the manual switch on you will wreck the
overdrive.
> - There's a small rusted box directly under the fuse box. My guess is a
> relay of some sort. There's nothing connected to it. Any ideas? There
> are also two tubular boxes, one to the front of the fuse box and one to the
> rear. I think one is the flasher circuit and the other is the ignition
> switch relay, but I don't know if I'm right or which is which.
The turn and hazard flashers should both be inside the cockpit, not the engine
compartment. The ignition relay clicks as you turn the ignition on and off.
There should also be a starter relay that clicks (if you can hear it) when you
turn the key to start the engine. If you have twin fans you may also have a
fan
relay that clicks when the fans come on.
> - The interior light works but only when used manually, not by opening the
> doors. There appear to be pin switches on the door frames. The driver's
> side door has two switches, one newer-looking plastic switch below the
> older-looking metal switch. Are these the switches to control the lights?
They should, but they tend to corrode and fail over time, particularly the
metal
ones.
Cheers,
PaulH.
|