2003 Ultra Electrical Problem

[cmotown1]

I have a 03 Ultra which consistanly drains the battery even when the car is off. I'll recharge the battery and everything works fine. But if I let it sit for a couple of days it will need a jump.

[HotZ28]

Is this the original battery? The first thing you need to do is, have the battery tested under load. BTW, what is the AMP gage reading, when the engine is running?

[cmotown1]

It is a new battery. I took it to budget battery and they tested under load. Everything tested ok, but there was still something drawing power from the battery when the ignition is off.

[Mickey#1]

Do you have a multimeter?

[cmotown1]

Yes. The battery reads 12.99volts

[HotZ28]

Rather than rewriting the book on parasitic drain, I will provide you with two threads, that give some good detail on the subject. Click Here & Here

[cmotown1]

Thanks HotZ28

[cmotown1]

I connected a multimeter to the negative and ground = 28.2mA

[HotZ28]

28.2mA drain would indicate nothing abnormal. Have you tested the alternator output with a multimeter with the engine running? Start the engine and put the multimeter probes on the battery positive and negative cables. You should be getting 14-15 volts soon after starting, and then it should taper off to 13.5 to 13.8 volts. If you have a bad diode in the rectifier bridge, it could be draining battery voltage to ground.

[cmotown1]

When I first start it I get 14.7 volts then it tapers down to 13.9 volts. Why is it if I let it sit a week without starting it I will need to jump it? Thanks

[HotZ28]

Originally Posted by cmotown1

Why is it if I let it sit a week without starting it I will need to jump it? Thanks

That is exactly what we are trying to figure out here. I know it rains a lot in Seattle, have you ever noticed any water inside the trunk (under the mat) or inside the car? Are all the options and wiring OEM, and nothing added like remote start? How long has this battery drain been going on? Did you buy the car new? You may have to go through a step by step process of elimination, to find the circuit at fault.

[cmotown1]

The car has been parked under a carport, so no water in trunk or inside. Everything is stock, but it does have a keyless entry remote. I may have to try the elimination process.