At 07:10 PM 1/3/00 +1100, Neil Cotty wrote:
>.... Been driving the A ....
>
>Initially, both the Fuel gauge and the Indicators stopped working. After
wiggling the fuses, the Fuel gauge started working again, but the second I
tried the indicators the Fuel Gauge went to zero! When I let the indicator
off, the Fuel gauge popped back on! ....
First, check the fuse again, and maybe do a special job of cleaning the
contact clips. It could still be a bad contact at the fuse clip. The fuel
gauge only takes a small current, but the tun signal draws about 3-1/2
amps, which could be enough to drop the voltage dramatically through a righ
resistance contact. Both are powered from the same fuse, so the current
draw of the turn signal could stifle the fuel gauge.
My next guess would be a short somewhere downstream of the T/S switch,
causing a very high current draw that would drop the voltage, but not quite
enough current to blow the fuse.
Please refer to this particular schematic for the MGA 1500:
http://www.ntsource.com/~barneymg/mgtech/electric/circ_f2.htm
or to this schematic for the MGA 1600:
http://www.ntsource.com/~barneymg/mgtech/electric/circ_f3.htm
For the 1500, if stepping on the brake kills the fuel gauge there could be
a short in the white/purple or white brown circuits to the rear turn signal
lamps (alsp brake lights on the 1500). This would likely manifest itself
as one brake lamp not illumunating. This would not be applicable to the
1600, as those brake lights are an a different circuit from the turn
signals. For the 1500 start by checking the wiring connections at the
relay box to be sure they are hooked up properly.
The rest gets more complicated and depends on the model of MGA. As I
recall you have a MGA 1600-MK-II, same wiring as the 1600, so I will start
there. Question: Dose the fuel gauge problem occur with actuation of
either the left or right T/S, or with only one side? The 1600 T/S circuit
is quite simple, with just the two (front & rear) bulbs downstream of the
T/S switch for each side. If there is a short in any of these wires or
lamp sockets the problem should occur only in one direction but not for the
other way. If it occurs for both directions on the 1600 I would be back to
suspecting the bad connection at the fuse. Otherwise there may be two
problems, shorts in both the left and right T/S circuits.
Back to the 1500 circuit, check to see if the relay box ticks once when you
actuate the T/S switch. If so look for a short downstream of the relay.
If not, perhaps the wires from the switch are not connected properly at the
relay box, which would mean some other wires there are also misguided. If
the problem occurs for one direction only look for a short downstream of
the relay. If the problem occurs for both directions, then perhaps the
flasher unit is miswired, or you may have shorts in both the left and right
T/S circuits.
If all this checking fails to resolve the problem, call back with the news
and any other symptoms you may observe along the way, and we'll go from there.
Regards,
Barney Gaylord
1958 MGA with an attitude
http://www.ntsource.com/~barneymg
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