test glow plugs?

[jiggs]

Hey Gang..
I finaly got my new starter for the antique 7100 kabota, have had the valves done and head reassembeled. I have to install the head but a bout with hospital has delayed that. I thought I would see if any one has an easy way to check or test the glow plugs for this unit I have the book and am not quite sure of what I am reading about it. one fellow says, just hook twelve volts to it and see if it gets warm.... well I did not do that of course. did no seem right. this is a first for me however I have been around small diesel engins befor. but just watched. Now it is hands on and of course the prepair manuel is at hand. I think I have turned enough nuts to get the job done. although the compression releas has not came up yet as to the setting but from what I read I do think I can follow the guide... well enough of this... really did not want to fry my glow plugs,, If they are good. paul /forums/images/graemlins/smile.gif

 

[BGL990]

If you have an ohm-meter, check the continuity of the plugs. They should be VERY close to a dead short - probably around 1 ohm or so. If you don't, then apply 12V as suggested. This is exactly what happens when you "glow" them normally. They should get very hot and quite quickly. The plugs in my mom's diesel pickup get red at the tip within 10 seconds and are bright orange all the way down to the threaded part within 30 seconds.

Be aware of a couple things:
1. It is possible the plugs are actually 6V plugs, which apparently GMC did on their pickups at one point. This was done so they would heat up faster and was compensated for by just not powering them for too long. As long as you can see the plugs (ie. remove them or if the head is still off) you will be able to apply power long enough to see if they are working without burning them out.

2. Some plugs are self-regulating where they will only get so hot and then level off. Others aren't and could burn out if you power them too long (even if they are 12V plugs). I would think that 5 or 10 seconds should be very safe regardless of the plug type and as mentioned above, as long as you can see them it will be immediately obvious whether they are working.

 

[LeRoi]

Another way to test glow plug is with a test light. I have one that looks like a screwdriver handle with a point on the end and a light bulb in the handle and a wire coming out of the handle with an alligator clip on the end.
You just remove the wire on the glow plug, put the clip on the positive terminal of the battery, and touch the end of the glow plug where the wire connects to it with the tip. If the light glows, the glowplug is good.
This method has never let me down on my ford diesel truck. I have never looked a a kubota glow plug, so your mileage may vary.
Leroy

 

[jiggs]

Many thanks guys. It all makes sense when talking to them that have been there. I will put this advice to work this A.M. I will let all know how the progress goes on this unit. been ten years since she ran, so I am thrilled each step closer I get to hearing her purr.

 

[MMM]

Better check for absense of a resistor in the circuit before hooking up to 12v. Some will burn out if hooked up direct to battery.