I tried to send this out earlier in the week, but I believe
is was lost in cyberspace...slightly modified repost follows:
> Update on the voltage stabiliser thing. 72 midget.
> Llyn Allen sent me a drawing using two 5 volt regulator
> ic's from Radio Shack. Put it together and receive a
> constant 10 volt output. Works the nuts!
The problem with using solid state regulators is that they're
not temperature compensated. Since both the original stabiliser
and the fuel gauge work with heaters, they behave in a complementary
fashion offsetting their own errors with regard to ambient
temperature.
I credit this observation to a Mr. Gregory Meldon who frequented
this list a few years back. He tried this experiment and went
BACK to that old rotten, thermo-electric POS that came with his
car. Not always easy to improve on good, solid LUCAS engineering. :-)
> However, the fuel gauge still doesn't work. I believe it to
> be in the sending unit. I'll drop the tank at the weekend
> and do some more tests.
Before you do this, take a few minutes to ground the sender terminal
of your fuel gauge. Turn the ignition on and look for a full
scale reading on the fuel gauge. If you have it, then the problem
lies with the sender or it's wiring. If not, your gauge is
bad. <or stabiliser> Don't leave the gauge grounded like this
for more then 30 seconds or so. Even with a full tank of gas the
sender still provides some resistance to limit current.
I just went through this exercise last month. <between snowstorms>
Of course, being a right thinking, American Triumph SPITFIRE
owner, I was able to pull the sender in less than two minutes
by opening the boot. :-)
I found two problems:
The sender arm was physically stuck in it's pivot...and I mean
_really stuck_. A few shots of Gumout carb cleaner loosened
it up nicely.
The float was three quarters filled with petrol. This was some
kind of translucent molded polyethylene affair with a welded
seam. I tried poking and prodding at it for over thirty minutes
in a vain attempt to find the hole....or otherwise get the
petrol out. Nothing.
I was forced to conclude that the petrol had, in the course of
22 years, been absorbed _through_ the plastic. <???>
Anyway...I drilled a tiny hole on one end, emptied out the petrol
and used compressed air to try to purge the vapors remaining
inside. I then heated up my small soldering iron and used a
scrap from a plastic milk bottle to weld the hole shut. I
WAS wearing a facemask....just in case. :-) Anyone care to
speculate how much damage this might have caused if it had
exploded?
It's hard to know how long this repair will last but the price
was right. Good luck with yours!
Regards...Tom O'Malley
'74 Spit...still hibernating
|