2001 Supercrew with 5.4 4x4....a always forget to state what truck it is so i got it out of the way first.

Here lately when I have gotten into the truck to start it it will turn over very slowly and then start...not never started. So today I checked the voltage on the battery after it had sat for a few hours...it was like 13.5. I started the truck and I get 18.0 volts. I shut the truck off and it jumped down top 15 volts or so and as I sat there I could watch the volts keep froming 15 all the way down into the low 13's. I hooked up a battery charger on a slow charge and came to work I will see how it is in he morning when I get home.

Is my battery going bad or do you think I have another issue...all cables and tight and clean.

 

If it's starting slowly with 13.5V, then either your cables/terminals have problems, or the starter is dying. Read these captions:



If the alternator is putting out 18V, there's a BIG problem with the voltage regulator, and a fault in the ground circuit could cause both symptoms. Read these captions:

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Took the cable off the starter and still having same issues. Made sure the cable at the alternator and wire are all tight and plugged in. Now its charging almost 19 volts...but nothing gets hot and it does not appear that the battery is boiling over.

 

Just started the truck while watching the volts and it goes from 13.5 to 9 then while the truck is try to start then it starts and jumps up to 18 volts.

 

19V is nearly impossible with an automotive alternator. Try a different voltmeter. What are you using? Even a cheap digital multimeter should be 100x more accurate than a needle voltmeter.

 

I am using a GB Instruments digital model. I think I have a cheap needle one around here somewhere to try out.

 

Gardner Bender to be more specfic. I put it on a 9V battery and it read 12.5V???

 

Your voltmeter is giving you worthless information. Possibly, this is due to a worn out battery in it. If that's not the case, I'd get a new multimeter.

- Jack

 

Yep it was the batteries!!!

Truck is fixed. It was just the battery. I hate to admit it but the batteries in my meter were bad giving me a flase reading...I feel like and idiot!!

 

Thanks to all in the help and advice!

 

Good on you! Interesting, isn't it that a weak battery in a voltmeter causes it to read "high". I only thought of that possibility because I've noticed some battery operated clocks run fast when their batteries are going.

But in fairness too, all your truck's symptoms pointed to a bad vehicle battery.

- Jack

 

Maybe it's time to step up to a meter with some kind of "LOW BATTERY" warning...