96 Xp no spark when Batt drops

[azsxr]

I just put a top end on and it started the first few times and then no spark. The Batt was at 12.6 I charged it up to 13.3 starts right up
every time . I drains it down to 12.6 and no spark. I have a new ground cable and a good pos cable the starter has new brushes and the
solenoid is new.
Any ideas?

 

[azsxr]

I swapped batteries with a known good one same thing above 12.8 starts right up 12.5 no spark. I tested the coil and it’s testing out of spec on the spades Im getting .7 and spec is .63 max so I’m guessing that’s it. I have 3 of these things so I’m gonna swap coils and see wtf.
I may have had this problem before but I always keep em charged up so maybe I haven’t seen this before.

 

[azsxr]

Not the coil???

 

[Mraw]

I would get the battery load tested.

 

[etemplet]

What is the battery reading WHILE cranking. I've had good starting with 11.5 volts while cranking. The voltage a batter measures does not correspond to its ability to deliver maximum starting amperage. Could be your meter.

 

[artr]

The 2 recommendations above are good ones. Since you said you swapped the battery with a known good one, I think there are a couple of tests you could do at home. First, As etemplet said, put a voltmeter on your battery and monitor the voltage while cranking. If the voltage does not stay above 10 volts then your CDI unit will not fire the plugs and load testing the battery will probably show it to be bad. If the voltage stays above 10 volts while cranking, the second test would be to put a voltmeter on the 12V input going to your CDI module. It comes from the output side of the Holder Relay module. Look at it while cranking with the battery at 12.5 volts. It should be the same voltage as the battery. As before, if it drops below 10 volts, the CDI will not fire.

 

[etemplet]

@artr that's good stuff right there bro. Great for troubleshooting !! That's next level shiznit !!

 

[azsxr]

Thanks for the help I’m getting the battery load tested today.

 

[POPPS]

Yup, lots of us on here have had "bad" new batteries,,,what colour is the spark? ,,,should be nice bright blue/white, and not a dull yellow/orange.

 

[azsxr]

It’s blue when it’s there.
The battery load tested good but right on the line. I’m making new cables to see if they help.

 

[azsxr]

Cables fricken cables, pos battery cable I think.I changed them all and it starts at 12.3 and I’m happy.
Thanks for all the help.

 

[NickCawks]

Those cables can be sneaky. Looking all nice on the outside and totally rotted on the inside

Glad it worked out!