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Matt
Matt, Mechanical Engineer
Category: Car
Satisfied Customers: 21869
Experience:  BEng hons Mech engineering, in auto industry 22 years
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Hi. When I turn my key the glow light sometimes dosen 't come

Resolved Question:

Hi. When I turn my key the glow light sometimes dosen 't come on and the car won't start . Try it a few times then it comes on and starts .
Submitted: 2 years ago.
Category: Car
Expert:  Matt replied 2 years ago.


I'd check that you're getting full power to the glow-plugs, they pull a lot of current so take care when checking but see if the relay is clicking when the ignition is turned on first and also check the fuse if this is OK check to see if the engine earth strap is also OK.

If the plugs haven't been changed in the last 20K then they may have to be replaced.

You can test the glow-plugs with a multimeter by measuring the resistance across the plug ( between the power connection and the body) it should be around 4-8ohms if its tending to infinity / open circuit the plug is faulty or by using a clip on current clamp, either on the supply wire to glow plugs or onto engine earth, with glow plug light on you should see 15-20amps for each glow plug fitted, 4 cylinders would be approximately 60-80amps.



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