I should learn to put my brain in gear before engage my mouth, er --- keyboard.
It's the washer switch line that gets grounded, the horns are directly powered.
I'll get a relay put into that circuit next week!
Tab, it might help to know what year your car is. There are quite a few
variations in the wiring schemes. If you have a 'later N. American' model,
which
would seem to cover 1975 on, the wiring harness contains a WG (white w/green
tracer) line that is connected to the first position of the ignition switch.
This
is for the radio power, not for the 'always hot' line to hold the pre-sets. The
white/green line allows you have the radio switched on without having to power
the
ignition circuit. The line for the radio pre-sets wants to be connected to one
of
the purple wires. In a 77, it's very easy to tap off of the purple wire that's
feeding the interior lamp. Don't use the purple/white, that's going to the door
switches and gets grounded. It may seem like a long way, but the handiest
ground
point for the radio is to fish the ground wire up to the area of the wiper
motor.
You'll find a number of black wires going to chassis ground right by (or on) the
motor. Easy to get to with the glovebox removed.
It's still possible that your purple circuit is 'grotty' as Paul put it. An
indication of this might be seen by sounding the horn while the interior light
is
on. If the light dims appreciably, you've got a grotty circuit and need to
clean
it up.
Sometimes it's easier to work around an electrical problem than to troubleshoot
the existing configuration.
Hope this helps,
Bud Krueger
52TD
77MGB
Tab Julius wrote:
> Well, stealing the ground seems to be the #1 vote so far...
>
> With that consensus, how should I consider fixing it?
>
> At 02:58 PM 11/13/99 -0800, Bud Krueger wrote:
> >Excuse me for not being specific re: colors, etc., I don't have a wiring
> diagram
> >handy. However --- I do recall that the horn is actuated by grounding the
> wire
> >coming to the horn switch. This means that the wire has 12v on it when not
> >actuated. I'd be willing to venture a guess that the radio is getting its
> power
> >from this wire. Sounding the horn makes the line go to ground, removes power
> >from the radio, goodbye presets. At least that's my $.02 worth.
> >
> >BTW, at least in my 77B, there is a separate wire for powering the radio when
> >the key is turned to the first position.
> >
> >Bud Krueger
> >52TD
> >77MGB
> >
> >Paul Hunt wrote:
> >
> >> Could be two seperate problems, especially if your radio is connected to
> the
> >> purple circuit (hot, fused) to maintain the station memory. The horns are
> >> also connected to this circuit and draw quite a significant current, so if
> >> the purple fuse is grotty sounding the horn could cause a significant
> >> voltdrop on the circuit.
> >>
> >> PaulH.
> >> http://freespace.virgin.net/paul.hunt1/
> >> (or if that URL doesn't work try )
> >> (http://194.168.54.52/paul.hunt1)
> >>
> >> -----Original Message-----
> >> From: Tab Julius <tab@penworks.com>
> >> To: mgs@autox.team.net <mgs@autox.team.net>
> >> Date: 12 November 1999 17:02
> >> Subject: Ghost in the Machine (part deux)
> >>
> >> >
> >> >The other week I queried about how my radio mysteriously played on after
> >> >the key was removed (and engine cut off, etc)., but the second I
> touched my
> >> >key to the ignition lock it disconnected (coincidence?).
> >> >
> >> >This morning, while having the radio tuned to FM 93.3 (playing a very
> >> >British Pink Floyd, btw), I realized that a quick honk of the horn cleared
> >> >power to the radio and I was suddenly listening to static on the default
> >> >89.7. I reset the station, did a quick re-test, and darned if honking
> the
> >> >horn doesn't pull the permanent memory power to the radio.
> >> >
> >> >I have a new radio to put in (not because of this, but because the current
> >> >one is a cheapo), but before I do I'd like to appease the Ghost of Lucas
> >> >and find what's rigged up wrong. Any ideas?
> >> >
> >> >- Tab
> >> >
> >
> >
> >
> >
> >
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