slow drag cranking
 

Hey , , help Please. 03 Duramax,,,starter is cranking at half speed Approx. Its like it only has 12v at cranking. Should have 24v. What could this be????
When it Happened//// I installed a new CP3. It cranked at normal speed,,, Got it started idled for 5 mins. Hit the gas peddle then died. Went to crank it again and half speed at cranking. Pulled and replaced starter. It's got 250K anyway.. I've checked everything. Even took the glow plugs out to relieve pressure. O'YEa. went back in to put new Pressure relief valve in. PPE. And check Connections. All is good!!!! Relay is good too. I did get a code P0193. Heater Intake. BUT it's connected. .

Thank you All,