I install a solenoid and a switch to manually control the glow plugs on my 1992 Chevy Silverado with the 6.5 liter Detroit diesel. This bypasses the factory controller that doesn't allow the glow plugs to cycle when the engine is at operating temperature.

Amazon Associate link to product(s) in this video:
https://amzn.to/428YXSZ Solenoid
https://amzn.to/3HOwY1T Toggle switch that will work well in the application. (not used in this video)

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