How do I test to see if my glow plugs are working (new holland Tc18)

[mcgills443]

Hello,

I was hoping to have someone explain where and how to test to see if glow plugs are working. I've been having a hard time starting tractor even when its in heated garage. I have to plug block heater in for 15 minutes before it will start. Any info would be great! thanks, Joe

[jenkinsph]

What I have done to check glow plug circuits is to put a current clamp around the hot lead that feeds them. If you know how many amps it takes to run all of them then you can get an idea whether or not all of them are working. As an example my truck pulls about 90 amps while the glow plugs are all on, if it doesn't read roughly the same amerage draw then that will indicate either the relay isn't working or if only about 45 am;s that half of the glow plugs aren't working. I start here and work towards the glow plugs and will check to see if some of them are opened up (no continuity). If the glow plug relay isn't working I trace the power back to the battery and fuses to find where it is loosing power. If you have power at the relay and are not getting the power to pass thru you likely need a new relay.
Hope this helps some.

[puckgrinder85]

Simple, 12v test light, test for power at the glow plugs, if you have power at all. Then do a resistance test of the plugs, they are generally around 1-2 ohms. Anything significantly higher or an open is obvious.

[mcgills443]

Hello, Update. I got the tractor running. I did check power to disconnect just before the glow plugs which was 12.43 same as battery voltage. I than checked where wire attached to 1st glow plug 12.43. I watched a couple youtube videos on how to use multimeter. I checked glow plugs by first checking volts in battery 12.43 . I than left red lead attached to battery and touched each glow with black lead that all measured 12.43. I was scrathing my head than When I brought tractor fuel filter was changed with 241 hrs. I only had 250 on tractor now. I took off fuel filter and the crud and ice was pack in filter. I changed filter drain fuel until it ran clear and put diesel fuel treatment in tank. I hope this fixed the problem. Thanks again! Joe

[jimmysisson]

If you have the time, plugging it in for an hour makes everything about a winter start better.
Jim

[mcgills443]

Hello, Update. I thought problem was fixed,but tractor still starts hard. It starts a little better when block heater is plugged in for a while. I took out glow plugs,and tested them with battery cables to found out they weren't no good. Glow plugs are suppose to turn cherry red within seconds,but they didn't even get warm. I Hooked up booster cables to:red to positive battery post. black to negative battery post. The glow plug end booster cables. red to tip of glow plug, black to threading on glow plug. I have glow plugs on order. Joe

[jenkinsph]

I recommend you check the glow plug controller too if you have one. If it sticks and lets them run too long it will burn them out prematurely.

[mcgills443]

Hello, I don't believe tractor has glow plug controller. glow plug stay on as long as I hold key in preheat position.
I put the new glow plugs in and what a difference I haven't had any more starting issues. We had some cold days 20* and it started first crank.Thank you for all helpful info. Gooday! Joe

[jaotguy]

if you want to bypass it all , use a FORD starter solenoid... power from battery (+ RED) to one big big post of solenoid, heavy wire from second solenoid post to glow plugs .. then run a wire from the small solenoid post to a push button switch on dash and connect second contact of switch to a HOT wire in the dash ....

pushing the new dash button energizes the solenoid as long as the button is pushed .... (glow plugs ON as long as you push the button)