EFI fuse keeps blowing

2005 SCION TC
113,000 MILES • 2.4L • 4 CYL • FWD • MANUAL
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ANN MARIE KELLY
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the other night driving home on the highway it shutoff and would not start. Once I got the car home I found that EFI fuse was blown. When I go to replace the fuse it blows before I can even get it plugged in and there is no key in the ignition. I then proceeded to check wiring for possible short and could not find anything. I then pulled the EFI relay and tried plugging in fuse and it did not blow. I also unplugged all the injectors plugged relay back in then tried to put fuse in and it blew. So is it a bad relay that is causing this?
Apr 6, 2017 at 4:12 PM
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HMAC300
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it might be try switching relay with a known good relay then see if it blows. if it does then just replace the relay, but if it continues then the wiring may be shorting against block or body if that harness lies against it.
Apr 6, 2017 at 4:36 PM
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ANN MARIE KELLY
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Thank you I will give that a try.
Apr 7, 2017 at 7:59 AM
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CARADIODOC
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Here's a trick to go with HMAC300's suggestion. Replace the blown fuse with a pair of spade terminals, then use small jumper wires to connect them to a 12 volt light bulb. A brake light bulb works well. When the circuit is live and the short is present, the bulb will be full brightness and hot so be sure it's not laying on the carpet or against a plastic door panel. Now you can unplug electrical connectors and move things around to see what makes the short go away. When it does, the bulb will get dim or go out
Apr 8, 2017 at 11:05 PM
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ANN MARIE KELLY
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Thanks for the info that seems a nifty trick. Car is at garage now. Once I find out what it was ill be sure to post it.
Apr 10, 2017 at 10:58 AM
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STRAILER
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Yep yep Caradiodoc is one of our best mechanics!

Please use 2CarPros anytime, we are here to help and tell a friend.

Best, Ken
Apr 12, 2017 at 6:49 PM
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CARADIODOC
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Thanks, Ken. I DO have a lot of people fooled!
Apr 12, 2017 at 7:40 PM