glow plug problems?

[94extcabf250diesel]

hey guys it been around mid 30's around here and lately my truck been a bear to start. i used my test light and hooked it to positive and checked all glowplugs. they all light up. but what i did notice is 3rd one back on passengerside it dont light up as bright as all of the others. should i change that one since it dont light up as bright as the rest? its only like half as bright whenever i use test light and test it.
thanks,
jimmy
ps i got a electric fuelpump on this truck and i would like to find and buy a check valve to put in my fuel line for this truck also. any tips where to find them at?

[seacow]

A good way to test the glow plugs is throught the use of an ohm meter, and i think a good glow plug should be around 2 ohms of resistance.

[cdnsarguy]

If you have 2 or more bad GPs, the controller may not cycle at all.

Two problems that occur with the solid state ( 1987 to 1994 IDI engines ) GP systems. If a GP burns out ( circuit resistance goes up ), the controller cycles the GPs at a faster rate which doesn't let them get to max operating temp. If 2 or more GPs fail, the controller may not cycle the GPs at all ( very rapid or no clicking heard ). When you check the GPs, use an ohmmeter. A high resistance ( not necessarily burned out ) GP can cause circuit resistance to go up and the controller will then cycle the GPs too fast. You probably will not find this problem with a test light. Resistance spec for GPs = .5 to 1 ohm cold. Second problem. A poor controller ground ( black wire attached to valve cover stud ) will cause the controller to leave the GPs on longer, often damaging or failing them. If you are having mulitple GP failures, I would check closely the controller ground. Now the confusing part. Bad ground --> longer GP on time ( slower cycling ). Burned out GPs --> faster cycling If you have both situations, it may appear that the controller is cycling the GPs at the proper rate. Bad ground slows it up while the burned GPs speed it up ---> normal cycling. The system acts/sounds like it's working normally, but you have a hard starting concern.
By........DieselDon

Glow plug torque is 12 ft lbs, I always use antisieze on the threads.

[JASTECH]

Here is a nice tid bit I found very interesting.

eBay Guides - Ford diesel glow plug relay trouble shooting

[FDCChief]

Has it worked well for you?

[paripam1980]

I have come up with a fool proof way to check glow plugs...works every time for me and is very accurate..
1) make a 12ga jumper wire about 30" long with alligator clip at one end, and strip about 1/2" the other end.
2) take a medium size flat screwdriver about 10" or so and clip the alligator clip to the top of the shaft, right below the handle.
3) wrap the rest of the shaft with electrical tape except for about 1/4" of the tip.
TO TEST: Disconnect each glow plug wire one at a time (or all at once if you want) then hold the tip of your screwdriver to the terminal on the glowplug and touch the other end of the wire to the B+ terminal on the back of the alt (or any other convenient B+ under the hood)
If you get a few little sparks, then that glow plug is working. Repeat for all eight

[Snotzalot]

An ohm meter is the best test, especially on an F Series. The E Series, being a bit tight, a test light is next best test.

[seacow]

as far as testing with an ohm meter what setting do you put the ohm meter too?? theres about 4 different settings???

[Snotzalot]

the lowest, usually 200