Got a ghost in car. Will not start, acts like battery dead, it ain't, got 12.4 volts. Will jumpstart from a 2nd vehicle.

Symptoms: With key on, eng. off, & all accessories turned off, sometimes (not always) speedo needle may jump from 30-110 (has 130 on speedo), wipers may come on by itself, 2 relays under hood might steadily click (fuel pump & a/c wid open throttle).

With key off sometimes stereo lights up & power antenna raises on it's own.

It's a short I'm sure, can anyone help? Welcome all suggestions & tips.

 

Battery might have 12.4 volts but it doesn't mean its good. Have it tested and replaced. Modules in cars can and will do strange and funny things when they're underpowered. When you place the starter load on the battery, the voltage is probably dropping to 3 or 4 volts.

 

yeppers those sensors an such , need a constant voltage supply to work rite, If it starts off another car , then I would say its a bad battery , or a faulty connection at the battery term. If you got one weak cell in the battery it will show good voltage , but wont be able to hold a charge or start the car, very common problem. You need to get the battery load tested most parts store will do this for free. Also if the Alt. is faulty an cant charge the battery it will give you problems , when you get the battery tested , they can check your alt as well .