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Mike S.
Mike S., ASE Certified Technician
Category: Cadillac
Satisfied Customers: 7500
Experience:  ASE certified
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My 2011 caddy Srx battery has only 4 volts, the car ran fine

Customer Question

My 2011 caddy Srx battery has only 4 volts, the car ran fine yesterday, tried to jump start it, but it would only crank for less than a second. It also said no fob present
Submitted: 1 year ago.
Category: Cadillac
Expert:  Mike S. replied 1 year ago.

Either something was left on or something is draining the battery. The best way to find out if first of all charge the battery overnite at 4 amps. Then with the negative battery terminal unhooked, place an ammeter inline between the cable end and the battery post with the negative test lead on the negative post and the positive test lead on the disconnected negative battery cable end. Place the ammeter on dc amps scale and with everything off, the reading should be no more than 50 mA. That's 0.050 amp. You may have to wait 30 minutes or so until the modules go to sleep, but after they do and the drain is over 50 mA, that is too much. Then start pulling the fuses one at a time and leave them out until the drain goes down below 50mA. Hook back up the battery and move the ammeter into the fuse socket that had the drain. Then refer to a wiring diagram and see if there are any branches on that fuse's circuit and then start disconnecting each fuse or item on that circuit until the drain is lower than 50 mA. Then when you narrow down what is causing the drain, inspect the wiring and/or part and see if it actually works, so put the fuse back in for now and see if everything on that circuit works.

Once you do determine which fuse it is if you need a wiring diagram, let me know which fuse it is and the ammeter reading.

Then using a voltmeter or 12 volt test light test the wiring to the affected part to see where it looses voltage and then either repair or replace the wire/part if it is indeed a faulty part shorted out.

Expert:  Mike S. replied 1 year ago.

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