Fifth Avenue - ignition kills electric circuits

Hey,

My 1985 5th avenue has been trouble free till now. Yesterday, I went
to start car - all electric features worked as typically expected.
When I attempted to start the car, all electricity to everything died.
Battery charge checks ok. I verified terminals on battery are clean
and connection is sound. It's like a circuit breaker tripped, killing
all electric circuits. This morning, I got into the car - lights
worked, radio, windows, etc. But when I attempted to start the car,
same thing happened. All electricity was cut to the radio, windows,
etc.

Any ideas ya'll have are most appreciated.

Thanks

 

Mike

But when I attempted to start the car,
same thing happened. All electricity was cut to the radio, windows, etc.

There are two power circuits that go from the ignition through the connector on
the firewall. Sometimes some of the individual pins/connectors get tired. I had
this happen twice on different vacations. Fortunately I had a voltmeter and my
service manual along and I did a fix. Actually a bypass wire until I got home
and put in the proper replacement parts. The AC blower and compressor was the
culprit. At the time I also added a high output alternator. I should have done
it before.

Bob AZ

 

How old is your battery? Sounds to me like it could well be the battery is
bad. When you say the electronics all fail, this could just be the symptom
of a battery dropping to a very low voltage when the starter is drawing high
current.

I'd attempt to jump start the vehicle and if this works, I'd suspect the
battery and/or charging system.

Good luck.

Bob

 

Sounds exactly like a bad connection at the battery terminal to me.
Remove, scrape or brush clean, re-install both the negative and positive
terminals. Bet it fixes it