How do I know if my glow plugs are working?
A number of faults can cause the engine warning light to illuminate – below, we outline the clues which point to faulty glow plugs.
- Hard starting. A hard starting engine is the most common indicator of damaged glow plugs.
- Engine misfiring.
- Rough idling.
- Decreased fuel efficiency.
- White smoke.
- Black smoke.
How do you test a glow plug with a multimeter?
Testing glow plug resistance: Turn on the multimeter and select ‘resistance’ or ‘Ω’ mode. Connect one multimeter test lead to a ground on the engine (preferably near the glow plug). Connect the other lead to the (power supply) terminal on the top of the glow plug. Read the result off the multimeter display.
What should I do if my glow plug is not working?
First, disconnect the wires from each of your glow plugs. Then, hook the clip of your 12 volt test light to the battery POSITIVE terminal. Touch the probe of your test light to the terminal of the glow plug itself (NOT the wiring harness!). Any glow plugs that does not light the test light is bad.
How do you test a glow plug in an engine?
Testing Glow Plugs in the Engine Grab a multimeter. Set your multimeter to ohms. Find resistance value of your multimeter. Test the voltage of the battery. Locate the glow plugs. Remove the caps or connectors to the glow plugs. Clip the multimeter’s negative lead to a ground point in the engine.
What should the EOT be for a glow plug?
EOT temperature below 55°C (131°F) for F-Series or 30°C (86°F) for Econoline. With the key on, engine off, measure voltage between center terminal of glow plug shunt and battery ground. If voltage is not present for at least 30 seconds, replace glow plug relay.
How is the resistance of a glow plug measured?
Check your shop manual for your vehicle’s test specs. Subtract the resistance value of your multimeter from the resistance value of your glow plug. For example, if your plug’s resistance measured .9 ohms and your meter’s resistance measured .2 ohms, the real reading for the plug is .7 ohms.