Cigarette Lighter Low Voltage

[cordovan66]

When I plug in my iphone auto charger into the cigarette lighter, its indicator light comes on for half a second and then turns off. I get this behaviour from 3 different chargers on both cigarette lighter outlets in my 2005 ES330. All three chargers work fine in my other car.

However, I have a power invertor which works fine on both cigarette lighter power outlets. I have to resort to charging my phone using the power invertor and mains charger in series.

I measured the voltage outlput at the cigarette lighter outlet and it gives just under 14V. However, when I plug in a charger, the voltage drops to around 7V. Apparently, there's a resistance in the circuit, maybe a bad contact somewhere. The invertor is apparently able to work on a wider range of input voltages than the phone charger.

Has anyone seen this problem before? Any suggestions on what could be the problem? Does anyone have a circuit diagram they can share? Thanks

[landar]

So the voltage drops from 14V to 7V with the charger. What does the voltage drop to with the inverter?

You are quite right that series resistance would cause this drop. The resistance would come from either the wiring or an inline fuse. Perhaps there is a common feed or fuse for all three outlets that is causing the drop. I would want to identify the fuse and check voltage right at the fuse as I loaded the circuit(with charger). You can trace the location of the resistance this way. If I understand the Lexus outlet design correctly, there is also a fuse built directly into the back of each outlet. The built-in fuse would not, however, explain why all three outlets behave the same. That suggests a common path resistance.

[cordovan66]

Can anyone provide me a circuit diagram please? Which fuses and connectors are involved in supplying power to the cigarette lighter?

Thanks

[landar]

You can purchase a complete wiring diagram for $5 or go to the Toyota TIS site and subscribe and download all of your cars info including Factory Service Manual for $15. But for this issue, you probably do not need a circuit diagram. Locate the cigarette outlet fuse in the fuse panel (if you do not know where the fuse panel is, look in the owner's manual). Then, using a Voltmeter, check the voltage on each side of the fuse with the outlet loaded and unloaded. Do you see any appreciable drop?