Difficult Cold Start
Several things could be causing difficult cold starts for your 5.9L Cummins:
Problem: Poor fuel quality If you suspect poor fuel quality, treat with Diesel Extreme. In winter, treat with a half-dose of Diesel Extreme and a full dose of Diesel Winter Anti-Gel.
Problem: Grid heater problem
A problem with the grid heater could be something as simple as corroded battery cables, making the heater not work at full capacity, or it could be a complete failure of the grid heater. If you have any questions, feel free to contact one of our diesel experts.