Cold start problems, plugged in

[jaggermouth]

Hi,
I was having problems starting the truck when it got around 0C so I started to plug it in. Would start first crank every time even at -20C.
Its gotten colder here and now the truck wont start even when plugged in over night.
The GRP tests out fine, batteries are new, and I get a WTS light.
I'm taking it to a shop after the Christmas break, but if a truck had bad glow plugs, would it still be hard to start even while plugged in over night at -30?
Anything else I should look for? It starts with ether (yeah yeah, blah blah, sometimes I need to get to work at 5am).
I don't have a garage or tools in Alberta with me, so I will be having her fixed professionally but would rather know whats wrong first.

[nathan]

I have never had one not start if it was plugged in. Could it be the block heater took a crap?

[jaggermouth]

I get a spark when I unplug it, and I tried testing it with a voltmeter to check resistance but I think I failed at that since it yielded many results aha.

[nathan]

Yeah, you should use an Ohm meter to check resistance. If it is good it should be very low. If it's not any good it will show zero because it is an open circuit.

[freeride707]

you may be having fuel issues. any codes? i know mine is hard to start all the time even plugged in. im working on figuring out the issue, could be IPR

[jaggermouth]

Check engine light isn't on but that doesn't mean there's no codes.
I'll just have to take it to Ford and see what they say. I hope its not a huge ordeal as my truck isn't even worth a lot.
Any other suggestions?

[jaggermouth]

Temps have dropped to around -10 to -15C and it started no problem after sitting for a week and a half (I plugged it in for 10 hours).
Safe to say my issue is glow plugs? If so, I have a cheap mechanic who will do it or I can do it my self in a month.