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4/19/2016 3:35 PM  #1


Low voltage when cranking

Brand new Optima Red Top. 12.6- 12.7v at battery. When cranking goes down to about 10.6v.​ Bad Battery? Starter? Solenoid? Something else? Thanks

 

4/19/2016 3:42 PM  #2


Re: Low voltage when cranking

I haven't checked one for years but that don't sound too awful to me.  Is that when you are continuous cranking...like for ten, twenty, thirty seconds or just normal start-up cranking...maybe three or four seconds?

You can make sure the clamps are all clean and tight and that the ground cable is bolted solidly to the engine block.  You know, that's why Ford put the pink wire bypass in from the solenoid to the coil...to ensure good spark for cold starting when the battery voltage pulled down to +- 9V.

BB
 


"you get what you pay for, good work isn't cheap, and there are NO free lunches...PERIOD!"
 

4/19/2016 3:48 PM  #3


Re: Low voltage when cranking

Contunuos cranking. Problem is the is not enough voltage to fire my MSD when cranking so just getting misfires and no start.

     Thread Starter
 

4/19/2016 7:18 PM  #4


Re: Low voltage when cranking

I was reading your post on another forum...you said it was cranking strong...that tells me its not a battery/voltage supply thing....re check the ignition wiring for correctness ...if it checks out good and no start,  replace the distributor and or coil...you want a blue spark at the plugs....my guess, a bad dizzy module....send it back to MSD... I had a similar  problem...they repaired and upgraded mine n/c in one week.... jj


"Never put a question mark where God put a period "  Richard Petty
 

4/19/2016 7:34 PM  #5


Re: Low voltage when cranking

If I put my timing light on the coil wire I get strobe. If I put it on the spark plug wires nothing. Does that sound like the distributor or box?

     Thread Starter
 

4/20/2016 4:31 AM  #6


Re: Low voltage when cranking

commish10 wrote:

If I put my timing light on the coil wire I get strobe. If I put it on the spark plug wires nothing. Does that sound like the distributor or box?

Bypass the box....jj


"Never put a question mark where God put a period "  Richard Petty
 

4/21/2016 2:36 PM  #7


Re: Low voltage when cranking

Don't sound like the box, a spark must be getting created if the trimming light is strobing on the coil wire. If you tried the trimming light on multiple plug wires, I'd day the spark is grounding out in side the distributer.


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