Will it never end?
#62
![Default](/forum/images/icons/icon1.gif)
Not yet. It's tough to track down because removing some fuses and then replacing them causes the car to "wake up". It takes about 20 minutes for everything to settle down to sleep mode. So I pull a fuse, the current draw doesn't change, then I reinsert the fuse, and the car wakes up. The current draw goes up to .8 amps for another 20 minutes.
#63
![Default](/forum/images/icons/icon1.gif)
Good grief! My head is swimming from all of this.
If you suspect the battery just disconnect it overnight, reconnect it in the morning and see if it cranks normally. Duh. If the parts store used a hand-held tester don't trust the results. I've been doing this professionally for 41+ years and I can guarantee you that no hand-held tester is 100% accurate 100% of the time (plus I was a MAC Tool Distributor for three+ years and have seen close to every tester on the market.)
The proper procedure for checking for parasitic draws in vehicles with electronics is:
1) Disconnect negative battery cable from battery. Either install a battery disconnect terminal or just use a jumper wire with appropriate alligator clips to bridge the cable to the terminal.
2) Connect a DVOM's leads alongside the jumper wire's ends and set the meter to 'AMPS' (and don't forget to plug the leads into their appropriate jacks.)
3) Open both front doors and both the hood (bonnet) and trunk. Close their latches/pin their switches in position as if they were closed - this will later allow access to the fuse blocks without triggering a draw and 'waking up' any electronics.
4) Leave the car set for 45 minutes. YES, 45 minutes! I don't care who told you or what you read, some modules don't 'go to sleep' any quicker. This is not a time to be impatient or not pay attention - but hey!, it's your 45 minutes, how many times do you want to do it all over? (for all I know there may be cars out there that require more time)
5) At the end of 45 minutes, make sure your meter is on, set to amps and not asleep (it happens and could cost you another 45 minutes... As long as you don't disturb the jumper lead you can do anything with the meter) Disconnect one end of the jumper wire without disturbing anything else. Your meter reading should hopefully be less than.030 amps with less than .026 amps being ideal. If your reading is higher begin pulling fuses, one at a time until the meter falls below .026 amps. I normally don't concern myself with the maxi fuses, they generally supply other groups of other fuses (or one large draw that, if active, will immediately blow your meter's internal fuse) - if you pull one and the reading drops you'll have no idea which fuse it is supplying without waiting another 45 minutes...
In regard to a bad alternator diode - yes, a diode can be detected (kind of) by low voltage output. However, a low battery and a few loads on can eat up a good alternator's output, resulting in a low voltage reading when everything is, in fact, o.k. There are only two decisive ways to determine a bad diode (without dismantling and desoldering) and that is to use either an oscilloscope or a meter with a ripple tester.
p.s. I know everyone here is trying to help one another but sometimes we have to employ a little outside help. When you do please remember that the difference between a free diagnosis at Checkers/O'Reilly's/Autozone/Advance/et al and a true professional is similar to sitting down to a rib eye steak at Morton's vs. one at the Waffle House. My dog might eat that Waffle House steak but I'll guarantee he'll be puking it back up before the day is over.
If you suspect the battery just disconnect it overnight, reconnect it in the morning and see if it cranks normally. Duh. If the parts store used a hand-held tester don't trust the results. I've been doing this professionally for 41+ years and I can guarantee you that no hand-held tester is 100% accurate 100% of the time (plus I was a MAC Tool Distributor for three+ years and have seen close to every tester on the market.)
The proper procedure for checking for parasitic draws in vehicles with electronics is:
1) Disconnect negative battery cable from battery. Either install a battery disconnect terminal or just use a jumper wire with appropriate alligator clips to bridge the cable to the terminal.
2) Connect a DVOM's leads alongside the jumper wire's ends and set the meter to 'AMPS' (and don't forget to plug the leads into their appropriate jacks.)
3) Open both front doors and both the hood (bonnet) and trunk. Close their latches/pin their switches in position as if they were closed - this will later allow access to the fuse blocks without triggering a draw and 'waking up' any electronics.
4) Leave the car set for 45 minutes. YES, 45 minutes! I don't care who told you or what you read, some modules don't 'go to sleep' any quicker. This is not a time to be impatient or not pay attention - but hey!, it's your 45 minutes, how many times do you want to do it all over? (for all I know there may be cars out there that require more time)
5) At the end of 45 minutes, make sure your meter is on, set to amps and not asleep (it happens and could cost you another 45 minutes... As long as you don't disturb the jumper lead you can do anything with the meter) Disconnect one end of the jumper wire without disturbing anything else. Your meter reading should hopefully be less than.030 amps with less than .026 amps being ideal. If your reading is higher begin pulling fuses, one at a time until the meter falls below .026 amps. I normally don't concern myself with the maxi fuses, they generally supply other groups of other fuses (or one large draw that, if active, will immediately blow your meter's internal fuse) - if you pull one and the reading drops you'll have no idea which fuse it is supplying without waiting another 45 minutes...
In regard to a bad alternator diode - yes, a diode can be detected (kind of) by low voltage output. However, a low battery and a few loads on can eat up a good alternator's output, resulting in a low voltage reading when everything is, in fact, o.k. There are only two decisive ways to determine a bad diode (without dismantling and desoldering) and that is to use either an oscilloscope or a meter with a ripple tester.
p.s. I know everyone here is trying to help one another but sometimes we have to employ a little outside help. When you do please remember that the difference between a free diagnosis at Checkers/O'Reilly's/Autozone/Advance/et al and a true professional is similar to sitting down to a rib eye steak at Morton's vs. one at the Waffle House. My dog might eat that Waffle House steak but I'll guarantee he'll be puking it back up before the day is over.
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mcbeefsteak (11-29-2011)
#64
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Thanks for the input, Beav. I did disconnect the battery and allow the car to sit overnight (two nights, actually). It measured 12.1 volts when I put the meter on the terminals, and it was obviously weak when I tried to start the car, but it did have enough juice to start (Although I had to reprogram my windows). So I do need a new battery, but I still have a current drain. This morning, after allowing the car to sit all night, my ammeter was showing about 280 miliamps of current draw and the battery read 10.4 volts. I rarely go more than a day or two without driving the Jag, so when the battery was fine it wouldn't have a problem starting the car after two or three days. But now, with a weak batt, it drains down overnight. A new battery will fix that problem, but it will still go flat if I allow it too sit too many days without driving it.
#65
![Default](/forum/images/icons/icon1.gif)
Here is my two cents worth. Bought Bosch battery's from pep boys for my vehicels for two years now.. have had to take back 3 of them , and argue with the manager that the battery's were just no good after there test said they were good. they just would not hold a charge after a month or so. so .. did some reading ,and went with Yellow top Optima battery for my truck and car .. not any trouble at all with Optima. not that it is the fix for this Sam , but Just some info on a great battery that I know does what it says its going to do. good luck with project.
#66
#68
![Default](/forum/images/icons/icon1.gif)
If you purchased it with a credit card you have a transaction they can look back on.
#69
#70
![Default](/forum/images/icons/icon1.gif)
If you have a Pep Boys reward card they will be able to look up your purchases via you phone number. Besides those thermal receipts will fade after a year. No receipt should not be a problem, at minimum you should get a pro-rated settlement.
The last two batteries I put in both have been Interstate Brand. The first one lasted just under 60 months. The last one has been in for less than a year.
Jag tested the last one. They kept it over night to do a full load test. It held the charge but failed for some other reason I think it had to do with weak cells.
The last two batteries I put in both have been Interstate Brand. The first one lasted just under 60 months. The last one has been in for less than a year.
Jag tested the last one. They kept it over night to do a full load test. It held the charge but failed for some other reason I think it had to do with weak cells.
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