Slant Six Forum
https://www.slantsix.org/forum/

Lost all electrical while cranking
https://www.slantsix.org/forum/viewtopic.php?t=63165		 Page 1 of 1
Author:  rich006 [ Wed Jan 09, 2019 6:22 pm ]
Post subject:  Lost all electrical while cranking
74 Dart has been driving with no problems. This morning when I turned the key, the engine started to crank for a split second, then quit. At the same time I lost all lights: brake lights, dash lights, dome light, etc. Nothing electrical works. I have 12.7 volts between battery terminals and also from the battery positive to the block or frame. There are no blown fuses under the dash, and the fusible link at the bulkhead connector has good continuity. Any ideas before I go tracing every wire?

The wiring is all stock and all the wires and connectors that I've looked at have been in good shape (minimal corrosion and brittleness).
Author:  Dart270 [ Thu Jan 10, 2019 3:49 am ]
Post subject:  Re: Lost all electrical while cranking
74 might still have all power going through the ammeter under the dash. Disconnect the battery and crawl under there and ensure the leads are tight.

Lou
Author:  Rick Covalt [ Thu Jan 10, 2019 5:25 pm ]
Post subject:  Re: Lost all electrical while cranking
Could it be the Ignition switch itself? You need to look at a wiring diagram to see how the fuse box gets fed and how the switch gets fed.

Wiring diagrams here.
http://www.mymopar.com/index.php?pid=28
Author:  Dart270 [ Fri Jan 11, 2019 2:53 am ]
Post subject:  Re: Lost all electrical while cranking
Ignition switch is another great idea.

Lou
Author:  emsvitil [ Fri Jan 11, 2019 3:21 am ]
Post subject:  Re: Lost all electrical while cranking
Put voltmeter on battery, then put a big load on it and see what happens to voltage. Attach voltmeter to posts and battery terminals as 2 different tests.
Author:  rich006 [ Fri Jan 11, 2019 2:13 pm ]
Post subject:  Re: Lost all electrical while cranking
Quote:
Put voltmeter on battery, then put a big load on it and see what happens to voltage. Attach voltmeter to posts and battery terminals as 2 different tests.
And we have a winner...

Instead of troubleshooting it myself I just took it to Sears for testing (yes we still have one). On the test printout there's a helpful note: AVERAGE BATTERY LIFE IN THIS AREA IS 51 MO. Mine lasted 52 months so I guess I did pretty well. :-)

Possibly interesting side note: before I went to Sears I took the battery to Advance Auto Parts and their test indicated it needed charging but not replacement. With that in mind I took the battery back home, reinstalled it, and jumped it from another car. Even after being on the jumper cables for several minutes with the "donor" car at 3000 rpm it was cranking too weakly to start the engine. That's when I took it to Sears where the test result was "replace battery."
Author:  Dart270 [ Fri Jan 11, 2019 2:35 pm ]
Post subject:  Re: Lost all electrical while cranking
Yes, always good to check batt and terminals and main leads before you do anything else.

Lou
Author:  Louise76 [ Sun Jan 13, 2019 10:00 pm ]
Post subject:  Re: Lost all electrical while cranking
Not the ignition switch: lights don't go through that. Corrosion?? on any of the battery cables, top and bottom ends, and inside the cable ends themselves? If someone installed new replacement cable clamps at the battery, disassemble those clamps and look for broken strands, corrosion, and general looseness. Clean everything with sandpaper or Scotch-Brite. Reassemble wet with Vaseline or a spray preservative of your choice. Lou had a great point also. These 74-75-76 cars had most other circuits going through the ammeter. Water leaks into the cabin and corrosion wreak havoc on those ammeter connections, so disconnecting and cleaning corrosion from the mating surfaces of the ammeter posts and the wire terminals is considered routine "preventative maintenance". Curious to hear what you find.
Author:  THOR [ Fri Jan 18, 2019 12:32 pm ]
Post subject:  Re: Lost all electrical while cranking
Quote:
Not the ignition switch: lights don't go through that. Corrosion?? on any of the battery cables, top and bottom ends, and inside the cable ends themselves? If someone installed new replacement cable clamps at the battery, disassemble those clamps and look for broken strands, corrosion, and general looseness. Clean everything with sandpaper or Scotch-Brite. Reassemble wet with Vaseline or a spray preservative of your choice. Lou had a great point also. These 74-75-76 cars had most other circuits going through the ammeter. Water leaks into the cabin and corrosion wreak havoc on those ammeter connections, so disconnecting and cleaning corrosion from the mating surfaces of the ammeter posts and the wire terminals is considered routine "preventative maintenance". Curious to hear what you find.
Looks like the the battery got replaced as it had gone bad. Got money's worth though, it lasted a month longer than the average life span of a battery in that part of the world! :shock: :lol:

~THOR~
Page 1 of 1 All times are UTC-08:00
Powered by phpBB® Forum Software © phpBB Limited
https://www.phpbb.com/