I have a 1999 Toyota Camry 3.0. I have had it for about 5 years now. Nothing aftermarket that I installed other than a receiver head. The car came with a Chapman security system although I have no key fob. Only a momentary ignition switch is installed that enables when the car dies.

My car was not charging properly at idle and was dying constantly. On alternator 6 or 7 now from auto zone. Noticed that idle was charging low and with ac it was only at 12.9v. I upped the idle to 950rpm-1k ish and now I'm getting proper charging at idle of around 13.5 with ac on. And 14.1 without ac.

I thought the idle fixed it, came back to my car after two small trips and it was dead again. I'm wondering if the security system is shorting the car. Debating pulling the brains out. Does anyone have any recommendations?

 

Are you using the alarm?

At 2K RPM the voltage should be 13.5 to 15.1 volt.

If your jumping the dead battery, are you doing it correctly?

Check for bad cables issues and bad battery cable grounds.

The IAC controls idle. There is no manual idle adjustment. Clean IAC valve. The internet has lots of video's on this.

Obtain an amp meter. Remove negative battery cable. Place amp meter in circuit with negative ground battery terminal and the battery terminal. Check for current flow with engine, lights, etc off and doors closed.

Normal battery drain with everything off should be 50-90 milliamp.

It happens that after market alarms drain batteries.

If the alarm has a hood switch, if possible wire the amp meter to be able to close the hood and view meter. Then lock car as you normally do and check for drain.