You may find that one particular item is giving a particularly high
volt-drop, but every item will be adding its little bit, and each little bit
will have been increasing over the years. Anything warm is exhibiting some
volt-drop. This is one of the reasons why the ignition relay was
introduced, as you probably know. You can either disconnect and clean every
connector, and test the ignition switch and replace if necessary (how much
voltage does a good one drop?), or measure the voltage at each point in the
circuit and decide if one is causing more than the others and just do that.
However poking around the connectors with a probe is quite likely to tickle
it up a bit and give inconclusive readings, only for it to drift back a few
days later to what it was before or worse. Probably the former is most
effective, but most work.
One thing to be aware of is that the igniton warning light comes off the
ignition switch harness connector in a lot of cases, so any volt drop that
is causing it to glow must be closer to the battery than that point, i.e.
you can ignore (for the purposes of extinguishing the warning light) the
white to the fuse block, the fuse block itself and the green circuit.
However you should also notice improvements if you clean up these as well.
Also the brown for the ignition switch and the brown for the fuse block
probably join together at a sealed multi-way connector behind the dash, so
you can ignore anything back towards the battery from there. That really
only leaves the harness multi-way connectors and the switch itself, probably
not too difficult a job.
PaulH.
----- Original Message -----
From: Florrie & Allen Bachelder <bachldrs@swva.net>
To: <mgs@autox.team.net>
Sent: Friday, January 07, 2000 5:05 PM
Subject: Soft Glow of Ignition Warning Lamp
> I finally got around to a little casual investigating. With a voltmeter at
> the fusebox, I discovered that while the voltage on the brown wire was
> about 13.5 volts, it was only about 11.5 on the white wire. Further, with
> ignition switch on and heater fan switched on, I shorted brown to white at
> the fuse box and noticed a distinct increase in fan speed. Similar tests
> using wipers and turn signals revealed similar improvements I would
> certainly welcome on this vehicle. I did clean up the terminals on the
> fuse box which changed nothing.
>
> So, I ask myself, what's between the brown circuit and the white circuit?
> Just a few feet of white wire, a couple of bullet connectors, the
ignition
> switch harness connector, and the ignition switch itself, right? '76s do
> have the ballast resistor for the coil, but no ignition switch relay.
Now
> I know I can trace this disparity upstream and locate the source, but can
> somebody save me from the discomfort of digging around up behind the dash,
> clutch and brake pedals digging into the sides of my head, re-inventing
> the wheel? My guess is that it's the ignition switch, although I can
reach
> under the dash and notice the harness connector is slightly warm while
> driving. Hmmm... Any thoughts?
>
> Thanks!
>
> Allen
>
> ******************************************
> Allen H. Bachelder =iii=<
> Sinking Creek Home for Wayward MGs
> 49 YT, 57 ZB, 58 ZB, 65 B, 67 BGT, 73 B, 73BGT, 76 B, &...
> New Castle, VA 24127
> USA
> 540/544-7333
> ******************************************
>
>
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