My truck has always made a "beeping sound" when I turn the key on, just short of cranking. After 4 or 5 beeps it would make a longer continuous sound. After that I would crank the truck. I have assumed that this represented that the glow plugs were warming and indicated a ready to start. Lately, the beeping sound has stopped when I turn the key on. It still beeps when the door is opened or the key is inserted. Does this have anything to do with the status of the glow plugs?

 

Check above you can't locate glow plug when it's not part of warning devices.





Pinpoint E pdf attached below. Just E.
Refer to key-in-ignition step 2 below, insert an allen wrench, pick the biggest diameter but slightly smaller than the access hole. Do NOT use any punch, pick or any screw drivers, use allen wrench only, if you don't have any, you can use T30 torx screwdriver (no T20, still too sharp head)

 

We might be workingon2 separate problems,,,,,,,,,.

Lets take the original question pertaining to the glow plugs.

Since we don't know for sure ,,,,,,,,,,,,we'll take a chance your vehicle has a 7.3 Diesel in it.

Does it have a "Wait" light on the instrument panel that needs to go out before you can start the engine?

If so, there is a Glow Plug Module.and a Glow Plug relay located at the top rear of the engine.The only way you can verify the glow plugs are working is to check for power at any glow plug when you first turn the key on and the engine is cold.The relay supplies the power. You should have 12 volts there. Do you have the 12 volts there ?

 

I can answer 2 of the 3 questions. The engine is a 7.3 Diesel. It does not have a "wait" light on the instrument panel. The part about checking for 12 volts is above my knowledge about how to do that.
I can say that it has been unusually cold here in Tennessee with temps well below freezing for the last week . I have kept the engine "plugged" into AC power and the truck starts just fine. Would this step eliminate the need for the glow plugs?

 

Usually the electric heater will eliminate the need for glow plugs, but,,,,,,,,,,that is as long as the heater is working and has power available.

You can usually feel the engine and verify the heater is working..
There is nothing wrong with having both heater and glow plug function available if needed.
The glow plug system should be checked BEFORE cold weather arrives.
The electric heaters always come with hazards connecting and disconnecting in cold wet conditions, so care should always be used.
The factory system is fine when working as designed.
During warm weather if one or more glow plugs don't heat, the engine will start without requiring heated intake air.
In cold conditions if a couple of glow plugs don't heat, starting can become a problem.
A WORD OF CAUTION ,,, never USE STARTING FLUID WITH AN ENGINE THAT USES GLOW PLUGS

 

Are you sure you're not hearing the SRS/RCM (Restraints Control Module ) beeping out a DTC/code? Generally the beep tones are counted and the long beep (long is a separator code) on the start events.

 

Assuming the key is out, simply based on this scenario, it is more than likely to be the key-in-ignition when its pins are still touching something and getting ground signal, this is a mechanical issue you might need to lubricate or bend the pins to get it fixed.
For the others like belt minder, headlamp on and door ajar, you should also see the associated LED illuminated on the cluster, if not it can be a sticky ignition lock cylinder (simply use "dry lube" to lubricate it on the bench) but then you would also get parasitic draw despite key out and the associated led is not illuminated on the cluster. To verify this use a scanner able to retrieve ford's specific DTCs you might see GEM or other modules that can't go into sleep mode when they are supposed to.
Whether or not the glow plugs are having issues, and doesn't matter how many beeps you are getting, troubleshoot this one at a time, check the key-in-ignition first, when It still beeps when the door is opened.

 

Thanks for the advice. Hopefully we'll get through the winter without an issue and I'll have my local mechanic check it next time its there. May watch some youtube videos to get a better idea of some of the things that were mentioned. I'll also take advice on "how to ask a question." Makes perfect sense.

 

What you should also do is to ensure your instrument cluster is fully functioning.





Pinpoint Test index page shown below. Check Pinpoint-All.pdf below if needed. At least verify any device that generates the beep, and ensure the associated LED proves out (illuminates when key in ON/RUN position, and turns OFF in a few seconds or when key in START position) correctly. If your door ajar LED bulb burnt out, you might have a bad ajar switch generating the beeps but you can't tell visually on the cluster, if that's the case check Pinpoint-S below.