Hard cold starts on a 6.7L Cummins often trace back to a failed grid heater relay. Diagnose and replace it for reliable winter starts.
electrical
🚗 Dodge Ram 2500
Easy
How to Fix Dodge Ram 2500 Cummins Grid Heater
Red Rocket
·
August 7, 2026
·
⏱ 1 hour
·
2010-2019 Dodge Ram 2500
0
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Step-by-Step Instructions
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1
Check for a P0670 glow plug control code.
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2
Test the grid heater relay with a multimeter.
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3
Replace the relay if it fails to pass current.
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4
Check the grid heater element resistance.
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5
Test cold-start performance.
Tools & Parts Needed
- 🔧 New grid heater relay, Socket set, Multimeter
Frequently Asked Questions
How long does this fix take?
1 hour
Do I need special tools?
Yes — see the Tools & Parts list above.
Is this covered under warranty?
Check your vehicle warranty. Some repairs may be covered, especially if the issue is a known defect.
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