My wait to start light comes on for about 15 seconds, but the glow plugs do not turn on. All 8 are brand new motorcraft. If I jump the relay for 10 seconds it will fire. I'm thinking of running a manual pushbutton as I can't afford a new glow controller. Any thoughts?
88 F250 7.3

 

The relay is bad. Get a new relay if u can. I thought my controller was bad and it was bad plug or two. She starts great now. I have switch wire still ran just in case. It starts great now. Is it making a clicking every second or so? Also take a test light, ground it and put it in a gp boot. See what the light does when u turn on the key. And then when u cross it.

 

No, it used to do the on-off clicking but it just stopped doing that. I need to hook up a pushbutton for temporary just so I can drive it for a while.

 

If your relay is bad as suggested then the remote push-button is no longer an option. Test your relay before you do anything else.

 

You can use a relay for the 86 style glow plug system, just bolt it to the 7.3 style controller and put the wires back on like they are now.

40 bucks versus over 100 for the relay/controller complete.

 

I put a new relay on, and my controller must be bad because the plugs still don't work. Can I manually rig up a starter solenoid? I know I can, but what does that metal slinky wire do? Does it change voltage to the plugs? I dont want to mess anything up.

 

I'm thinking about putting a pushbutton on mine too. Some days the plugs cycle normally, and some days they cycle like a couple plugs are burnt out. I don't really get it but it's annoying.

 

I got a manual glow system I put in parallel with my controller.

The problem with using the solenoid on the controller is that it is very likely the part in the controller that quite working when you really need it so I rigged up a Motorcraft starter solenoid with a push button an wired it directly to the terminal on the glow plug controller that goes to the glow plugs. Make sure you get it on the right side of the large resister.

No matter what happens with the controller, my manual glow system will always be there as a back-up if I need it.

Sadly both my glowplug controllers on my trucks seem to be slowly dying. They work most of the time but every once in a while I noticed this winter they won't come on or stay on long enough and I have to reset the ignition to get them to work.

The old controller on my 93' also seems to be having a harder time after I recently put it all new plugs. I sounds different and does not click the way it used to.

I guess I just going to have to spend the money to replace them once I get fed up enough with them, much like my IP and injectors I recently replaced.

The good news is that all these things seem to die slowly so you got time to repair while the sun is still shining.


Seb......

 

87 and later glow plug controller/relay.



Manual control.
Attach a wire to the white wire terminal and run it inside the cab.
Mount a momentary switch in a convienent location and attach the wire from the controller to one terminal.
Attach a wire to the other terminal and run it to a good electrical ground.
Done.

Operation.
Power is applied to the ignition terminal when the key is on.

So you must have the key turned to on.
Push the switch for 10 seconds, start the engine.

In extreme cold, then engine may start running rough, push the button till it smooths out, usually around 6 seconds, that was called afterglow on the stock controller.

 

I did this, the plugs work, but the relay buzzes very loud when I push the button

 

Sounds like the relay is fubar.

 

Thanks for posting that, dave.

Guess I need to pick up a switch somewhere.

 

Hey Dave does that method completely bypass the controller, like it won't try to automatically cycle when the key is turned?

Also is there only a small amount of current that actually flows through the switch?

 

If you leave the white wire attached it will try to cycle normally, if you remove it, then it will not.

Power is applied to the trigger coil on the ignition terminal when ever the key is on.
So the white wire provides a ground to complete the circuit.

Very low power draw on the trigger circuit, so a small amp switch is fine as well as small AWG wire.

That said, mostly because of vibration I use 12 AWG for everything I wire as a small wire.
And as an electrician I have several thousand feet of 12 gauge wire in various colors.