Need some tools to diagnose battery drain on car?

[Mac]

Yeah, I used to see a lot of devices like those. My last job was at a Roush dealer, and so we kept a lot of Mustangs on the lot and sold a lot of them. It wasn't uncommon for customers to come in complaining about the battery being dead every time they went to drive the car, which they only did once or twice a year. We ended up installing a lot of those things.

The one thing I've found out about the later Mustangs is that they can go dead in 2-3 weeks if the radio is still on. I parked mine for the Winter, had the radio off and 2 1/2 months later, fired right up. And how do you only drive a Roush once or twice a year? The OP really shouldn't his going dead that quick. All I know about electricity is black to black, white to white and green can go anywhere.
Dave

 

[feellnfroggy]

Best way to begin checking for drains before hoking up allthe big equipment is to put your simple ammeter on the terminal and pull fuses, watch for the drain to go away. You can wedge teh probes down into most terminals witout messing them up. Once you narrow that down it will usually leave you 5 or 6 paths to check up on. But anything that charges or has some kind of inverter on it such as laptop cords and gps will draw a charge enough to fill the charging unit till its turned on. Kinda like a capacitor