Starter or batteries???
 

Guys having trouble with truck wanting to turn over after been sitting like over night. It'll turn over but starter turns over slow. but during afternoon hrs or after its been started it starts fine. Batteries are 5yrs old. Any advice or tips be appreciated. Thanks

Best to get your batteries tested somewhere, and go from there. If they test OK, it may be a parasitic load on your batteries overnight. A load as small as 1 amp can have an affect on the starting performance in the morning.

Had them checked and they are both rated at 850 but they are pushin like 680cca. I live in ky and the coldest morning we've had so far has only been about 31 degrees normally around low 40's. bought new ones anyway so guess we will see in the morning how she starts.

If you have a Volt meter handy do a cranking voltage test. First check your open circuit voltage by placing your test leads across the battery posts and you should see between 12.4v and 12.7v. If it reads under 12.4 your battery needs charged, if above 12.7 but below 13.0v you have a surface charge and need to get rid of that by simply turning on your headlights for a few minutes, if over 13.0v you have a sulfated battery and most likely needs to be replaced. If you read between 12.4v and 12.7v, check your cranking voltage. Put your test leads across the battery and have someone crank the motor. You should see at least 10 volts, if under 10 volts your batteries are bad and need to be replaced. If you read above 10 volts your batteries are good. Next I would check the voltage drop across the starter. Do this by putting the positive lead on the B+ terminal of the starter solenoid and the negative lead on the ground of the starter. Have someone crank the motor and record that reading. You should only see a 1.0 drop between your cranking voltage test and this reading. Example; Your cranking voltage is 10.4v and your reading at the starter was 9.6v, that is a voltage drop of 0.8v and is excellent. If you read anything drastically more than a 1.0v drop then check your connections from the starter to the starter solenoid, starter solenoid to the starter relay and back to the batteries. Look for any corrosion at the contacts and replace bad connections/wires. Don't forget to check your grounds! You should see as close to 0.0v on your ground connections and close to your cranking voltage on the B+ cables. If you're reading 3.4v on a ground cable when cranking then you have a bad ground cable or connection. If you're reading 7.8v on a B+ cable when cranking then you have a bad B+ cable or connection. If all looks good then it would only make sense it is a mechanical issue. Example; starter pinion not engaging correctly, engine compression high, high viscosity motor oil, etc. Hope this doesn't confuse you:humm:, but this is what any good technician would do if your truck went into a shop.