After being plugged in overnight, my 73 showed no signs of life, just cranked and cranked. I put a meter on the block heater plug and got 15 ohms. What should it read??

 

That reading sounds in range. White smoke out the tailpipe while cranking?

 

The only thing I am ever concerned about with anything that relies on an element to produce heat is if it were to be burned out. Then your meter would show "OL" for out of limits. Your element is drawing about 8 amps (120 volts/15 ohms), which any 15 amp circuit in your house or garage can handle and sounds about right as noted above. I don't have my diesel anymore or I would do a comparison for you.

Steve

 

After being plugged in over night......... Was the engine "warm to the touch" ?

Hobo

 

Even in the cold (-20) my old 7.3 would cough and fight if I parked it somewhere where it couldn't be plugged in. It'd rattle and shake and start and die a few times but it would show life. How cold is it that it isn't even attempting to fire?
I would be looking into other causes such as your CPS.

 

It was only 20*. GP and relay are only 3 months old. I used International parts.
300k on the odometer, maybe I need to do a compression test

 

‘How long are you waiting AFTER the WTS light goes out? Keep in mind on the pre 02 trucks the WTS light has ABSOLUTELY NOTHING TO DO WITH THE Glow Plugs. The PCM uses the EOT to determine IF and the length of time the GPR activates the GP’s. If conditions are cold enough the GPR will stay activated for 2.5 minutes...! That’s a SIGNIFICANT drain on your batteries, which brings us to the next point. How old are your batteries?
You need 10.5 V to activate the electrical side of the injectors and if the GPR is on that easily brings the amps down to 10.5-11.5 with the truck OFF.

Start with cheap and easy fixes first.

1) Charge batteries overnight
2) Use a timer and let the GPR stay on WITHOUT trying to start the truck for 2 full minutes .
-During these 2 minutes do the following:
3) While key is in the ON position (GPR should be activated) use a multi meter to check your voltage at POST 2 (always hot 12V)
AND POST 4. Post 4 should show same voltage as Post 2...IF GPR IS ACTIVATED.
4). Are you getting 12V to Post 4 when GPR actives???

5) At 2 minute mark turn key to START...did it start??

If batteries are more than 3 years old charge over night and get them Load tested.

 

I attempt to start after the light goes out. Batteries are 1 year old and AGM. I'll get a meter on it.

 

That's some engine that will start in -20* weather. By CPS, do you mean cam position sensor? If so, it is a year old and a Ford sensor.

 

Have you tried giving the glow plugs 2 minutes to actually heat the cylinders up? I wired an LED in the cab to post 4 in the picture, when the GPR actives the LED turns on. I KNOW it’s working and for how long.