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Voltage drop at ignition

Grey Roams

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I'm running into this problem with my 1982 Datsun 720 pickup.

It won't start due to:

12 volts going into ignition connector( where the ignition coil is. What the okay of the key sticks into to turn the truck over)

 aux: 1.3 volts coming out. 

Start: 1.3 coming out.  L(when everything thing is plugged in and turned on: 1.3 volts)


I tested:

all relays

ignition coil

the 3 fuse links from the battery

The starter and starter solenoid (which are new)

Pulled off wall: fuse block

Checked all fuzes


I'm at a bit of a loss on what to try next.. help y'all?? Thank you




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First measure across the battery posts. A charged battery is about 12.6 volts.


Now across the battery cables. If less, then the cables and posts need to be cleaned and properly tightened. If you have crappy after market nut and bolt on cable clamps get rid of them and buy better ones.



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pull the light swtich does the lights come on at reasonable briteness? then try to start does lights go out? then I would say weak battery or corrossion


to ck for corrossion i get a volt meter and but 1 lead on the battery post and one on the cable  at the plus or munis side of battery. I alwasy do + side. put the key to ON. then if you read a voltage drop between the 2 then corrossion or weak conncection. as you should read ZERO as really it should be shorted.


One thing I ask is you getting what voltage at the starter selinoid???  with the wire out of put in voltmeter.



I assume you get 12volts at the + side coil. but when you hit the key you say it goes down to 1.3volt?



I had a battery cable post crack on me. that caused a No start with a load. sitting there my meter would always read OK

Edited by banzai510(hainz)
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