06 Freightliner slow cranking / won't start

sounds like the engine may be in the process of locking up or out of time, coolant level low or empty and if you add coolant does it go away after say 10-20 min?. I would not throw any more money at the starting system. and look at a internal hard part issue. Good luck

 

That hot cable is a clue. Heat is electrical restance and thats just what you don't want. Check that cable, clean both ends with a wire brush till its nice & shiney. You didn't say if the truck ran before you did all this or had dead batt. so I assume that it did run just was having starting problems like now. If all else fails take the starter back off and have it checked even new parts sometimes are bad.

I'm also assuming that you did charge the batteries! Even new off the shelf batts should be charged.

 

but even new batteries off the shelf won't make for a hot power cable to starter.

like u said. resistance is the key. if that power cable is corroded. that might be the answer to all your problems.

check for voltage drop on the cable. put the positive end of meter to the battery side of cable. put the negative end of meter to positivie post on the starter. you shouldn't have more then .5 volts. anything higher indicates resistance. ( this is cranking voltage, not at rest voltage)

on th4e negative cable the voltage shouldn't be any higher then .3 volts. again, cranking volts.

word of caution though. that information is for cars. i can't remember what the spec. should be on semi's but it should be somewhere in that same range. you have much longer cables on a semi but your also pushing my higher amperage to overcome that longer length.

the reason your not starting is the simple fact that your cranking really slow. something is pulling to much amperage and dropping the volts too low. in general, the computer needs a minimum 12 volts while cranking in order to make things work. i think a semi can make things work with 11 volts though. as there's no ignition system.

what's the cranking voltage at the batteries? measure the batteries while the truck is cranking.

 

Have you tried jumping off another truck an seeing if it would start than? Any codes coming up?

 

oh yeah, that would be another thing to check. the CHARGING SYSTEM. if your alternator isn't putting out 14 V. it may not be charging the batteries completely.

but that still wouldn't explain the HOT BATTERY CABLE at the starter.
i'm with the above poster. bad cable.