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What would cause the 20 amp fuse to blow that powers the glow-plug relay? I have noticed that the ground side of relay continues to be closed for a period of time. Beyond then the "wait to start light" goes out on instrument panel. Any ideas?

Answers from the Automotive Experts

Amanda J. Pierce, MBA Judy If your vehicle is hard to start even when ambient air temperature is fairly warm your glow plug relay maybe shorted out. Inside your fuel filter canister there is a fuel heater..it may look like a coil/spring in the bottom, they are known to fail at times and cause a fuse to pop. These components are all linked as a way to start so your fuel is warmed at start.

Laurie Sarno, Co-Owner at Super Girls Auto Hello Judy, More than likely, either the relay is faulty, or the glow plugs themselves need replaced, as with any electrical resistance heating element, they will draw more power as they age and the resistance increases. There is also a remote chance of a short in the glow plug wiring circuit, but this is very uncommon. Hope this helps Super Girls Auto

Lori Johnson, Owner and Instructor at Ladies Start Your Engines Dear Judy, A fuse*s job is to protect the circuit it*s on. If it blows it usually means there is a problem with the device or a short in the circuit. If you replace the fuse with the same amperage and it works fine, it could have just been a surge in the system. If it continues to happen, have a technician diagnose the problem. I would suggest that you contact a Ford dealer, they may know right away what your problem is. Lori Johnson

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