Ignition powerloss issue

[davidschaffer]

96 7.3 with added electric fuel pump. So, when I go to start the truck, every now and then I get a huge power loss while waiting for the glow plugs, such a loss that the truck won't start. Yesterday, while it was acting up, I tried to diagnose it. What finally worked was disconnecting the glow plug relay, when I did this I had minimal power loss,( just the normal from glow plugs and electric fuel pump), the truck started right up and the battery went immediately back to the 14v range, oh yea, that's the other thing, when it is acting up (glow plug relay connected) if it does start, the battery takes a while to get back to 14v. I assumed it must be a bad relay and replaced it but no dice. Any suggestions?
Also, my braking is suddenly much softer, unrelated to the above, but still a problem I'd like to fix.
David

[Chop]

The glow plug relay can stay energized up to two minutes depending on the ambient[outside] temperture,this is why amp gauge draws down and this is normal and expected from a well mantained PSD.From what I understand the oil temp dictates the duration of glow plug cycle. Cold weather and weak batteries are not friendly to the PSD,Having said that,is it cold?are the plugs working?

[davidschaffer]

Temp dosn't seem to make a differance, what I don't understand is why it only sometimes draws so much power that the truck won' t start, i can start it a 20 degs. sometimes no problem, run it for the day, try starting it again even if its 70 out and may be it will start maybe not. sometimes sucks the batteries dead, sometimes doesn't. with the gpr disconnected, never have a problem.