Really hard to start when cold, found heater plug

[Word]

It's been getting down to the 20 degree mark here and been having starting trouble since about 45*f or so. Once it got down to 35 and below, started after 30 seconds of cranking but only ran for 5 seconds (did this about 4 times before finaly started and stayed) and blew tons of smoke when it did start. Now that it is in the 20s i get no start at all with good crank. I found my heater plug and plugged it in for 4 hrs and it started right up like it was 90 degrees outside. I do not have the glow plug light lighting up so I guess that is an issue but i do hear the relay cycle when I turn the key. Can the glow plugs not working make that much of a difference? or do you think it is something else also?

[bondsman]

Pull some codes... We don't have a glow plug relay. Our trucks have a glow plug module. It is on the passenger side valve cover at the front. Your module could be going out, bad glow plugs, bad harness(s). How is your FICM? Check voltages before you start, while cranking, and while running.

[Word]

I am sorry, My truck is an 04 but I still have the 03 motor in it. I am new here and not really a mechanic but learning, I could be wrong but I thought I had a relay by the alternator? As for all the other stuff you mentioned I have no idea or equip to measure voltages

[bondsman]

Here is what it looks like. Not a typical glow plug relay.

NEW 01-10 Ford 6.0 7.3 6.4 Glow Plug relay OEM module - eBay (item 230560089320 end time Dec-12-10 14:52:16 PST)

You will need a dgital multimeter to check the voltage at the FICM (fuel injector control module - located on the driver's valve cover).
Your best bet would be to post your location and maybe someone with an autoenginuity would be willing to lend a hand with diagnosing.

[Word]

Thanks, I am 20 min north of Pittsburgh, Pa

[futbal2332]

If possible, use a timer when you plug your truck in, it uses a lot of electricity when pluged in all night. set it to come on a couple hours before you need to leave. i havnt plug my 08 yet since i bought her, it was in the low ten last year and i didnt have a problem, now this time its getting cold and she hesitates to crank and she needs to warm up before i can drive her or she sputters.

[Chango]

for info on how to test the ficm check out the no start thread in my sig also check out the oil / cold start one