My truck has been cranking slow and the other morning at 25 degress and plugged in all night it cranked over 3 times and that was it ! Glow plugs are fine , bateries check out ok on load test and hydro test on cells , cables had a little bit of corode but nothing that was that bad , batteries were replaced 2- years ago with Interstates , new heavy duty gpr , new starter 2 1/2 yeats ago 150,000 miles on truck . Next thing to do is take voltage drops on cable while cranking . The other morning when it would'nt start , I hooked it up to a heavy duty battery charger in the boost mode for about 2 minutes and it started right up with no trouble or smoke . What am I missing and are there certain areas that are a reoccuring problem ?? I don't want to jump the gun and start throwing staters cables or batteries at it .. Thanks

 

Don't forget to look for corrosion on the other ends of the battery cables. Did you disconnect the batteries and load test them separately? It sure sounds like you've got a weak battery.

 

I agree. I had a week battery. Turned over fine, but would not charge. Check them together and it looks OK.

 

Tested batteries seperate and are clean .

 

could be and altenator problem have them checked out! if ya have 2 of them!

 

How do you disable the starting circuit so you can crank the engine over without it starting ? I need to take voltage drop readings on the battery cables and don't want it to start ?

 

Unplug the CPS.

 

Thanks Kris