Mike,
The tach runs off of unregulated ignition voltage (it has an internal zener
diode that takes care of "calibration" in the Lucas sense) so if the tach
died also, then the instrument regulator is not part of the problem, unless
it shorted right out (i.e. to ground). If that happened, it would have blown
the fuse or melted the regulator, and you wouldn't have got the gauges back.
I'd put money on a bad ground, or a bad switching contact on the turn signal
stalk.
Theo
> -----Original Message-----
> From: Michael McBeth [SMTP:mmcbeth@compusmart.ab.ca]
> Sent: Tuesday, April 25, 2000 7:15 PM
> To: Tiger
> Subject: Lucas woes
>
> I may have an answer on this, but if anyone would like to corrector
> confirm my
> guess before I buy a part long distance. As I was driving yesterday I lost
> my
> Tach reading, my water temp, fuel gauge, and turn signals. After sitting
> (shut
> off) for some time all came back... until I used my turn signals again.
>
> The last time something similar happened it was just the ground that
> 'daisy-chains' the gauges, but this shouldn't affect the turn signals.
> Deciphering the wiring diagram it seems that the instrument voltage
> regulator
> is probably the culprit, but I'd rather be sure before hunting one down.
> Any
> one care to confirm, venture another diagnosis, or offer a test to find
> out?
>
> Gotta love Lucas, diagnosis by exactly how many electrical devices don't
> work.
> Unless I have two problems simultaneously...
>
> On a fun note, I did trounce a V8 MG conversion before I lost my tach.
>
> Michael McBeth
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