When starting from cold it is hard to start. It maybe a problem with the circuit to the glow plugs or the glow plugs themselves. Advice please.

Hard to start because the glow plug circuit is not working. Sounds like the glow plug is defective and the relay is opening and closing. Replace the glow plug.

first try to put a wire direct from battery to the bar that feed the positive on your glow plugs for 15 seconds take wire of and let it some one turn ignition switch to see if it will start then you know it is in that circuit. look for the glow relay maybe faulty relay or fuse

The glow plug light is telling you there is a problem with the glow plug circuit. There is a controller and the glow plugs themselves can fail. In your case, I suspect the controller.

The 4500 John Deere tractor sounds like the glow plugs are not working. Checked voltage at the glow plugs to make sure that there is 12 DC volts.(Might have to remove main wire from the glow plugs to check!) If no voltage at glow plugs there maybe a bad fuse,relay or wire connection in the glow plug circuit. If there is 12 DC volts at the glow plugs, it is possible that the glow plugs need to be replaced.

Check for power on the glow plugs. You have two fusible links on the passenger side by the stater relay and a plug going over to the engine. These plugs get intermittent and that can cause your hard starting; the glow plugs themselves maybe burnt off. I've seen this happen with the other Ford diesels in our tow trucks!

sounds like a vacume leak this can stop cold engine from starting. vacuum leaks can be hard to find, it could be just about anywhere. when you have engine running spray the easy start or carb cleaner around the vacume lines, note any engine sound changes. and that will be where the problem could be, say could as it could have more than one leak.

Hi Mike:
Glow plugs-on fed truck usually the controller-on cal.equipped truck usually glowplugs themselves.

We are assuming the you have some of this codes:
- P0380 Glow Plug/Heater Circuit A Malfunction
- P0381 Glow Plug/Heater Indicator Circuit Malfunction

I found this after searching this and other diesel sites for about a week glow plugs are covered on factory extended warranty-10 years or 200000 miles call GM @ 1-800-462-8782 have VIN# ready

Models: 2002 - 04 Chevrolet Silverado
2002 - 04 GMC Sierra
Equipped with 6.6L Diesel V8 (RPO LB7 - VIN 1) Engine; and California Emissions (YF5/NE1), or Clean Fuel Emissions (VCL)

Condition: Some customers of 2002 - 04 model year Chevrolet Silverado; and GMC Sierra trucks, equipped with a 6.6L diesel V8 (LB7) engine, and California emissions (YF5/NE1), or Clean Fuel Fleet emissions (VCL), may experience a condition where the engine glow plugs may fail. Failure of the glow plugs on these vehicles will cause illumination of the MIL. Also, depending on the ambient cold start conditions and the number of glow plugs failing open, some customers may also comment about hard starting, misfiring and white smoking after cold start.

Customer Notification: General Motors will notify customers of this special coverage on their vehicles (see copy of typical customer letter included with this bulletin - actual divisional letter may vary slightly).

Ask your local dealer.

Hope this helps; also keep in mind that your feedback is important and I will appreciate your time and consideration if you leave some testimonial comment about this answer.

Thank you for using FixYa, have a nice day.

year model? Engine size? I need a little more information than ford won't start when cold. I would guess either the glow plug relay or the actual glow plugs themselves are bad, but usually the glow plug relay, because if it were just one or two glow plugs it would start, but run like ****.

Have you checked all of your vacuum hoses for leaks? Any vacuum leak, even intake manifold or throttle body gasket, will cause an engine stall right after starting. Likewise with a fuel pressure problem. If you aren't getting voltage, maybe whatever switch starts your glow plug cycle(either turning ignition on or opening driver door, depending on model) is defective, or any of the wiring of the circuit. It's a cheaper guess.

You will need some decent spanners, the nuts are 8mm on the wiring and some will need a 1/4 drive socket, some a small spanner, get decent glow plugs, maybe citroen ones, there are som unreliable ones out there, even the Bosch ones sold by factors are not as good as factory! the plugs themselves are usually13mm and tight. You may have to take some air filter or emission stuff off but not the fuel injection pipes, leave them alone!