volts question - car won't start

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66lark - 20 Apr 2006 23:52 GMT

1966 Buick. AT. Points distributor.
The car won't start. It cranks but it won't turn over. I put a
voltmeter on it with the engine off.
I put the red probe on the positive battery post and the black probe on
the negative battery post and it showed 12.65. I put the red probe on
the positive battery post and the black probe on the alternator case.
That showed zero. I then put the red probe on the positive battery post
and the black probe on the engine block. That showed zero. I did the
same thing only with the red and black probes switched and I got the
same readings - 12.65, zero and zero. I tried this on my truck which
has no problems and I got 12.65 every time. What could be the problem?
Also, can anyone recommend a beginners book or a good website on using
a voltmeter / multimeter to test car electrics?

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clifto - 21 Apr 2006 00:20 GMT

> 1966 Buick. AT. Points distributor.
> The car won't start. It cranks but it won't turn over. I put a
[quoted text clipped - 7 lines]
> same readings - 12.65, zero and zero. I tried this on my truck which
> has no problems and I got 12.65 every time. What could be the problem?

It sounds like your negative battery cable isn't connected well,
either at the battery end or (more likely) at the grounded end.

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Mike Romain - 21 Apr 2006 00:36 GMT

Your negative cable has a bad connection.

I start 'walking' the meter back. I put the positive meter probe on the
battery post. I then go from the engine block with the black probe to
the bolt holding the negative cable onto the block, then to the washer,
then to the cable end, then to the clamp at the battery, then to the
battery post. When I find volts, I have found the bad connection.

You can to the same on the main cables for the battery positive. Start
with the negative and positive probes on the posts, then go to the
clamp, then the cable, then the other end clamp or loop, then the
washer, then the bolt. When you lose voltage of any amount you have
found a bad connection.

You also can try to start it a couple times and carefully feel the cable
ends. If it clicks and tries to turn, one cable end will be hot, even
burning hot so be careful.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
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> 1966 Buick. AT. Points distributor.
> The car won't start. It cranks but it won't turn over. I put a
[quoted text clipped - 9 lines]
> Also, can anyone recommend a beginners book or a good website on using
> a voltmeter / multimeter to test car electrics?

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Steve B. - 21 Apr 2006 04:32 GMT

>1966 Buick. AT. Points distributor.
>The car won't start. It cranks but it won't turn over. I put a
[quoted text clipped - 9 lines]
>Also, can anyone recommend a beginners book or a good website on using
>a voltmeter / multimeter to test car electrics?

The starter grounds back to the battery through the block to the
neutral wire that is hooked up around the intake manifold. The
starter pulls a couple hundred amps on that car in the best of
situations. If the engine is cranking but you are reading 0 volts
between the positive terminal on the battery and the block then you
aren't getting a good connection... There just isn't any way that
connection could carry a couple hundred amps and not be able to show
at least some voltage via your meter.

Steve B.

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