Hi All, my LS430 05, all of a sudden one day wouldn't start in the morning. Upon investigation, I found the 10A INJ fuse blown, I took one from Horn, same 10A, put it in and it started without problem, next day I drove all day about 100miles and on the way home, all of a sudden all lights came on and the engine stopped. I managed to roll down to the house where it sits now. Upon looking, I found that the same fuse is blown again. Got a box of 10A fuses, put one in, try to start and it now blows it right away. Any suggestions of what may cause it? I have a 1998 Ls400 and 2005 lx470 and never had this issue. Could not find anything on the internet either...
Thanks in advance for any recommendations.

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Fuse number 74, INJ, 10 ampere protects the multiport fuel injection system. However, according to the owners manual so does fuse 75, IGN, fuse 83, EFI No.1, and fuse 85, ETCS.

Hopefully rkw77080 can chime in here with some schematic information to see exactly what systems fuse 74 protects. In the mean time it might be beneficial to look at any of the wiring going out to the fuel injectors to see if there is any chafing in any of it. Got any mice in the area where you park your car???

 

Agree with Gronemus... Look for chafing in wires that is touching bare metal.

The 10A fuse "INJ" provides power to each of the 8 ignition coils via a red wire. One of them is intermittently touching bare metal and blowing the fuse.

 

rkw77080, Gronemus - thank you for your quick replies, thoughts, recommendations and attachments. There is indeed a mice in the area where the house is, but all 3 Lexuses are parked outside, though LS400 is not driven regularly, and LX470 may be too tall for mice to get in, so the 430 would be the only low and warm car to get in, so mice damage is theoretically possible.
Unfortunately, its being raining cats and dogs in the area where I am in last couple of days, and suppose to rain more next few days, so it would be difficult to look further. I will check once it clears up and will let you know. Cheers!

 

rkw77080, Gronemus - thank you for your recommendations, it turned out that you were right on the spot! Once the weather permitted, I pulled up the plastic engine cover, and the first thing I see is the chewed up red wire touching the engine block - the obvious cause of the short. Apparently, mice completely chewed up two wires that led to a connector (pictured). I am not sure what that connection do, but the car did run without it for a day (on 7 cylinders?).

As you can see it was difficult to come up with an easy solution to re-attach the wires. What I eventually came up with is to screw in a short screw in the connector, so that it touches whatever left of the wire in the connector, and then attached the remaining wire to the screw, wrapping the whole thing in black tape to firmly secure it. Once completed, the car started without problem and runs great so far.

Again - thank you for your quick recommendations, that saved me from towing the car and potentially running a high bill from the car shop!

Cheers!

Paul

 

Glad to hear that your electrical problem is resolved.

The connector is for a Noise Filter (one on each bank). For a more permanent repair, the connector part number is 90980-10843.
https://www.lexuspartsnow.com/parts/...980-10843.html

 

Thanks for reporting back and closing the loop. It's always helpful to know the root cause of the problem...

 

Every so often, I'm reading posts about mice attacking the car's wiring. I do see mice in the yard but I don't see them in the garage, so I'll hope for the best and try to keep them out of the cars.
Glad you were able to fix the problem and thank you for the follow up