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MG MGB Technical - Green Wire question

1977 MGB with wiring problems.

I can't locate a 2nd one-to-three green connector / splitter coming off the fuse box. The one I've found is on the main harness, passenger side, slightly to the rear of the fuse box. The wiring diagram I'm working from says both greens split into 3.

I've been working backwards from the voltage stabilizer and found a shorting issue. One of the green wires at the fuse box... the one going to the voltage stabilizer... causes the fuse holder to heat up. Don't know why the fuse doesn't blow but I'll be checking the fuse size shortly. When I disconnect the green from the fuse block it cools down.

If you know where my "missing" 1-to-3 green connector can be found please let me know.

Thanks.

Brian Denis

Sometimes a fuse won't blow because there are bad connections in the fusebox which limit the current to less than the fusing current. These bad connections cause volt-drops which case the fusebox to get hot as well as limiting voltage to components even when the short *isn't* present.

The connector you've found is logically the one that feeds the washer pump, brake light switch and brake imbalance switch all of which are in the engine compartment. The other feeds everything else which are all inside the cokpit and will be behind the dash. Where behind is the fun bit. It has one branch to the wiper motor and other branch to a third 4-way connector. One branch from that feeds the wiper switch, multi-plug for the dash wiring and voltage regulator. Another branch feeds the handbrake switch and seat belt warning light. If you locate both these, and start pulling wires from them, and noting which circuits still have power when you have disconnected the short, you will gradually track down the location of the short. Tip: if you replace the fuse with a 12v headlamp filament it will glow very brightly when the short is on, less so if at all when it isn't.
Paul Hunt

This thread was discussed between 29/08/2004 and 30/08/2004

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