Hey guys...have a question about starter/alt charging system.

I ran out late last night to respond to a call, hopped in, turn the key...wouldn't turn over.

Battery is about 2 months old. Charged the battery this morning, cranked up just fine.

Metered the battery while running:

- No acc on: 13.9 - 14.09 volts
- With lights on: 13.7 volts
- Lights & A/C on: 13.55 volts

So, seems like the alt is charging ok. It's a few years old.

Battery reads 12.6 not running, as it should be.

I let it sit for awhile, turn key, motor turns very slow (just like you hear in a horror movie when the girl is trying to get away). Turns like that maybe 3-4 times, then motor cranks.

Turn off, turn key within a minute or so, cranks right up. Just went out there, barely turned and wouldn't start. Just had it running 15 minutes ago. Now battery reads 10.5 after trying to crank it.

Did find a starter test in Chilton, turn key, battery shouldn't read less than 9.6 while starter cranking, it went down to 6.xx volts.

So..I guess my starter is going bad? I believe it's the original...so..

If it is the starter, I'm confused why it's killing so much of the batteries charge. Trying to draw to many amps, etc?

Let me know your thoughts and anything else to try.

Thanks

 

I would start with new cables. My Mustang did that years ago. On a hot restart, it showed the starter drawing 700amps!!! Replaced the starter and the new one did the same thing. My ground cable was bad, even though it looked fine. If not, then the starter could be on the way out.

 

700amps...damn, I don't have an amprobe, so not sure what kind of amps it's trying to pull. Change out the battery cables to start? Yeah, this starter, if original has 201K miles on it. I bought the truck w/34K so, I'm sure it's OEM.

Alt charge rate sound ok? I always thought it needed to be 14-15v, but Chiltons says different.

 

A lot of places like AutoZone can test the battery and starter for free. I don't know if the starter has to be out of the truck for them to test it though. But I definitely suggest having them do a thorough load test on the battery, if a cell or two is going bad it will initially read good voltage, but any normal current draw will quickly kill it.

What brand and size battery did you get? It may be defective.

 

Didn't even know they could test starters, batteries yes. Just called Advanced and they can bench test it. Will also take the new battery as well tomorrow morning.

It's a Duralast Gold 65DLG/Cold Cranking Amps 850/Cranking Amps 1000/Reserve 150.

Just went out after it sitting all night, battery reads 12.6V. Cranked it, motor turns like in a horror movie, after 4 very slow rotations she cranks. Battery was reading 5.5 volts while cranking.

Let it run for 10 min, shut down, waited 30 sec, cranked right up, battery reads 10.xx v, shut it down, crank it right back over...same thing...very slow and battery reading 5.xx volts. Per Chilton it shouldn't go lower than 9.6.

Sounds like the starter to me?

 

Starter for sure... Also I have taken a truck to auto zone for testing and everything tested fine... So i started to chase other things that were not the problem. Come to find out it was the starter the whole time. If your starter is that old I would replace it.

 

That's my line of thinking also. Still gonna take it down there in the morning and have them test it, just to see what they show. I'm leaning 99% towards bad starter.

 

Let us know what happens... My thought is it will fix it.

 

I sure will, thanks everybody.

 

ive got two of those same batteries and both have been great. im interested in the resolution also