My 68 cutlass won't start. Went for a drive, shut it off for 5 minutes then wouldn't start. It starts to crank but only gets maybe one revolution. Like a dead battery. Put another battery in same thing. Had the starter checked it's good. First I thought the starter got hot but next day nothing. 12.5 v at the starter, from the main + lead. Motors not locked up I pulled the spark plugs and it cranks continually.

 

You put another battery in, but how do you know either battery is good? Have someone load-test yours.

How did you have the starter checked? I'm not familiar -- does someone actually make a fixture that measures the torque capability of a starter?

Other than those two ends of the system, anything in-between which impedes the flow of electrons will prevent the starter from giving full output. Check the positive cable to the starter and the negative cable to the block -- not only the cables but their ends and the surfaces they bolt to. Everything needs to be clean and rust free and connections tight!

 

If you have 12.5 volts at the starter I'd say your battery is charged. Like Brian stated, clean all the cable ends including the grounds. Make sure they are all tight. Inspect the positive cable for fraying and chaffing. If all that fails to get the car to start easily, then look at replacing/rebuilding the starter.

 

Actually it should read a little over 12.6 V for a fully charged battery at about 70 deg F. At 12.5 V it's either really cold outside or the battery's only charged maybe 80%.

Also, it's possible for a battery's voltage to read OK but not be able to deliver the current required by the starter. As the battery ages (or gets damaged in other ways), it essentially starts acting like a smaller battery.

 

That's true but he said he changed the battery with the same result. With a weak battery the voltage reserve drops quickly after a couple of start tries.

 

The batteries are both new within 3 months, I bought one for my Cutlass and one for the Toro. Had one on a charger overnight and tried it again. Same thing. Starter was tested at Autozone tested fine, and tried two others I had that were known to be good just to make sure. Same result. Same voltage at starter and battery so I'm thinking positive cable is good. Also have continuity from the block to the neg battery post. It's got to be wiring somewhere else

 

Its the current availability that drives the starter, you'll read voltage and continuity even if you only have 1 strand of wire left in the cable. I"ll put my money on poor/loose connections.

 

I had a similar problem with my son's blazer . it turned out to be the bolt that the negative cable was connected to. It was corroded not where the cable was but down inside the aluminum intake. The starter was pulling ground through the ground strap that goes from the battery to the body . Which just wasn't big enough and it acted just like a weak battery.
Railguy

 

K so I made a better connection between the wire that goes to the pos battery terminal and the horn relay and it started. Yeehaw!
But, tried to start it again and no luck. Got to something in that connection though.

 

Where does your negative cable connect on the block? Is there a bolt with a stud on it?the problem I had was the whole bolt needed to be taken out and cleaned not just the nut on the stud.
Railguy

 

At this point, you need to either clean and measure resistance on every component between the battery and the starter, or check voltages at every point, while cranking.

So, with a helper, use a good voltmeter, attach the black lead well to the negative battery terminal, touch the red lead to the tested point, and crank for a second or two.

Check the positive battery terminal, the positive clamp on the battery terminal, the other end of that wire where it connects to either the starter or the horn relay, and each point there is, all the way down the line, and write down the numbers.

At some point, there will be a drop - that is the point where the starter is being starved for current, so go back and check whatever is connecting the last place where voltage was high and the first place where voltage is low.

- Eric

 

Remove all doubt. Use jumper cables direct to the starter lugs.

 

Ok I'll do that because it started a couple times but now still same problem

 

The thing that alerted me to the negative cable was the ground strap or wire that goes to body got very hot when trying to start the vehicle.
Railguy

 

Mine will never turn over when it's hot unless I hit the key once and then the second time it turns right over. I always assumed it was a weak starter. The timing has been checked and all the cable connections are good.