Erik,
See commentes in your message below.
Peace,
Pat
- Support Habitat for Humanity, A "hand up", not a "hand out" -
Pat Horne, Network Manager, Shop Supervisor/Future planner, CS Dept,
University of Texas, 1 University Station C0500,Austin, Tx. 78712-1188 USA
voice (512)471-9730, fax (512)471-8885, horne@cs.utexas.edu
On Tue, 6 May 2003, Amy & Erik wrote:
> I asked a question about my 68 2L strangely blowing the fuses after a cold
> start, and the ammeter going negative when I shift to reverse.
>
> Long story short:
> I checked the light first to see if any power make it to the back of the
> car. I turned the key to "on" and shifted into reverse, no light. I
> checked the connections and it looked fine.
According to the wiring diagram, the backp light will operate only when
the key is on.
>
> I tried starting it because I wasn't in the mood to dive under the dash to
> look for bad wires, and what do you know, the reverse light now works.
This is strange, but probably an intermittent short between the wire
between the backup light and the backup light switch on the trans to
ground. Some times I've seen this when the switch wires under the car get
against the exhaust pipe and the insulation melts, allowing the wire
inside to short to the exhaust pipe.
> I am
> used to cars where all the electrical stuff works when the switch is in the
> "on" position. Anyone else with a high windshield, do you need to have the
> car running to get the reverse light to work?
Nope, the engine can be on or off, as long as the ignition switch
is on.
>(wipers and fan works when the switch is on)
Is this with the blown fuse in place, or a good fuse. The wipers, fan and
backup light all hang on the same fuse.
> The ammeter doesn't dive when I shift to reverse anymore, so I guess I may
> have had a loose connection, but I didn't see it. Haven't blown any more
> fuses.
Is the fuse that blew the one marked ignition? That's the 20A, on the end
of the fuse box, next to the 10A fuse. If so, the fuse blowing and the
backup light not working are probably related. If you shift into reverse,
with a short in the backup light wiring, the ammeter will swing negative,
because the short will dump more current than the alternator can supply,
so the extra current comes from the battery. This current flows though the 30A
fuse, which will blow the fuse in short order. I believe auto fuses are
rated to hold a 100% overload for up to one minute before they blow.
>
> I did find another strange thing. The ammeter goes slightly positive when I
> hit the brakes. All other electrical sruff causes a slight shift to
> negative. Should I just call this a quirk of a 30+ year old car, or is it
> something I should investigate?
Don't worry about the slight positive indication. The voltage regulator is
an on/off tpe device that mechanically approximates the required voltage.
Sometimes it is a bit high, sometimes a bit low. The alternator puts out
pulses of full charge, followed by times of no charge (fractions of a
second).
> The only non-stock thing I have done is the EI conversion. I can't see how
> this would effect any of the above.
This shouldn't cause any problem.
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