My tbird is eating batteries

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My tbird is eating batteries

October 10, 2007, 03:13:34 PM

For some reason my tbird zaps batteries to 6 volts as soon as i hook up the cable. Is it a short or something running all the time and draining it?
My bro had a drain on it at one time. I replaced the interior harness because my bro left the original 87 wiring in with standard options and i have a sport with all the options. I hate wiring (sigh) lol
I`m dyin to take it for a spin cause i havent driven it in 3 years. I forgot how much power it has.

jaguar tech says try this....

Reply #1 – October 10, 2007, 05:54:11 PM

disconnect your good battery. pull every single fuse you have.... reconnect the battery, turn the key in the on position. hook up a dig. volt ohm meter to the battery. have a friend watch the readings to tell you when it changesput in one fuse at a time watch for the readings to drop 6 volts or whatever the drain is you are talking about then you will know which circuit to check all the powers and grounds...

My tbird is eating batteries

Reply #2 – October 10, 2007, 06:22:50 PM

I am guessing it makes a lot of sparks when you hook up the battery.

Leave the negative battery cable off. Hook a test light between the negative battery cable and the negative battery terminal.

If you have a battery drain the light will light. Pull fuses and disconnect stuff until the light goes out.
A "normal drain" like the dome light or the under-hood light will cause the test light to light. So keep that in mind as you trouble shoot it.

Loading a good battery down to 6v is a big time drain. Do you see anything smoking? A load like that would blow a fuse or a fuselink. So it must be something that is not protected by a fuse or fuselink.

My tbird is eating batteries

Reply #3 – October 10, 2007, 06:52:32 PM

yea i see it sparking when i hook it up. nothing smokes and everything seems ok til i turn the key. it has a good connection to the battery. we had this problem before but i dont know what it was.

My tbird is eating batteries

Reply #4 – October 10, 2007, 07:10:54 PM

Even the starter won't pull a good battery down to 6 volts. If your battery is good (and charged) and connecting the cable brings the voltage down that far it would literally blow the cable out of your hands, the spark would be that big (it would take hundreds, if not thousands, of amps to pull a good battery down that low - a 600 cold-cranking-amp battery shouldn't drop below 10.6 volts at 300 amp draw for 10 seconds). It would also melt the insulation on the cables within seconds.

Are you saying the voltage doesn't drop until you turn the key? To which position - "start" or "run"? Does the engine turn over at all? Where are you measuring voltage? Are you measuring at the battery terminals themselves (NOT the battery cable ends, but the actual lead terminals on the battery)?

Regardless, if your battery is dropping to 6 volts it is very, very dead and will need to be charged and verified OK before you can accurately diagnose anything.

My tbird is eating batteries

Reply #5 – October 10, 2007, 07:44:59 PM

actually nm it`s dropping to 11 volts. when the key is turned to start and the starter just clicks. This has been holding me up for a while

My tbird is eating batteries

Reply #6 – October 10, 2007, 08:59:13 PM

ok I just fixed it. headlight switch was stuck. I feel dumb now lol. next problem is I cant get any fire in the engine. it just cranks and cranks. I had it running not too long ago wtf.