I have a glow plug question. I'm pretty sure the glow plugs in my 86 6.9 are bad. I still need to check them to make sure though. My truck is set up with a push button system. Do I need to stick to the stock 6 volt plugs or do I need to switch to a 12 volt plug? Or do I just need to limit how long I cycle the glow plugs? If this is the case, how long should I cycle them?

 

Your should have a spade connection on the glow plug.
Replace them with Motorcraft/Beru ZD1A glow plugs only.
10 seconds for a cycle time with the push button.

 

Thank you for the information. It has been very useful.