1989 Ford F250 7.3 Replaced glow plugs, I have added a relay switch, which I just replaced as well. Tested each glow plug all were getting 12V. Truck started great for about a week, now it will only start if it is plugged in for at least an hour. I am in NE Arizona present average temps are 75 daytime and 50 nighttime. If I park the truck for about 6 hours even with the warm weather it will not start until I plug it in for at least and hour. Bad glow plugs? Anyone experienced this.
Thank you, Shortie
Thank you, Shortie