Not always & seemingly at random. Just like at startup after battery reconnect.

Most searches come back only with incidents at startup only. Recommendations say battery &/or alternator. Battery is Optima Red that's been in there maybe 6-7 years and all connections are clean & reads 12.48 at rest.

Alt is a AC Delco new unit replaced 20k or so ago & reading 14.24 at idle with or with out any accessory drain on the system or RPM.

Troubling thing is a code for coil misfire on # 5 which put it into limp mode (I erased & so far hasn't returned) & some comm issues with the Inova 1403 that I'm using.

Any recommendations?

 

WHICH needle?

 

Needles would mean all.

 

At this age, both the battery and the alternator are suspect.

The battery needs to be load tested to see if it's failing. The output of the alternator needs to be checked while it's driving to see if it's intermittent, usually due to worn brushes starting to "float" and loose their connection.

 

Might be able to secure a load tester this weekend. Also a chance then to drive it with a meter hooked up direct.

Will let you know. Thanks.

 

Follow up...

Dug out my load tester & checked the battery: Dropped to 9.5 during test which is weak & should be replaced.

Drove a route with DVOM hooked to battery and different loads on engine. Average output 14.24 to 14.48 so I think that's OK.

After swapping #5 coil to #6 position & seeing fault code move, I replaced the coil with a parts house unit till I can get to the junk yard & grab a selection of stock coils for the future.

Here's the kicker... No more pegging the needles since coil replacement. Several days here lately of 20s-teen over nite temps & no degradation of cranking energy that you would expect from a weak or dying bat.

 

Mine acted up it turned over really slow.Had battery tested and it showed good. I put on a battery tender and let it sit for a few days. No issues since and that was over a year ago.