turbonut Posted April 8, 2008 Share Posted April 8, 2008 turned key in ignition just, one click.....nothing thought battery running down of late, had new one put in yesterday, that didnt work either! it only had 10.5V Had recovery out, he used booster pack. I took it for a 45 min run and later it just about started up. Got it home, checked voltage, back up to 12.5V Checked voltage this morning back down to 10.5V Is something draining the battery overnight? Is it the starter motor or distributor? Help!! (distraught) Linda Quote Link to comment Share on other sites More sharing options...
Havard Posted April 8, 2008 Share Posted April 8, 2008 Could it not just be the alternator? H. Quote Link to comment Share on other sites More sharing options...
Pig Posted April 8, 2008 Share Posted April 8, 2008 Could it be your alternator has gone down? Hence not charging the batt after a drive. Quote Link to comment Share on other sites More sharing options...
Supra ST Myster Posted April 8, 2008 Share Posted April 8, 2008 you need to see what the voltage is when you manage to start the car again, wants to be around 14.2V Quote Link to comment Share on other sites More sharing options...
turbonut Posted April 8, 2008 Author Share Posted April 8, 2008 you need to see what the voltage is when you manage to start the car again, wants to be around 14.2V After using the booster pack on it yesterday it was up to 13.5V spoke to a mechanic friend who says sounds like the alternator's draining the battery thanks for the suggestions, got to get it started and get it to a garage....looks like the recovery peeps again L Quote Link to comment Share on other sites More sharing options...
Tricky-Ricky Posted April 8, 2008 Share Posted April 8, 2008 Sounds more like the battery not holding a charge properly to me, if its showing just over 12V after a drive but going down to 10V after sitting, if there was a problem with the alternator it wouldn't charge as a rule, you really need to put a meter on it to be sure, a good check is if its showing over 14V when running then its very likely to be the battery. Quote Link to comment Share on other sites More sharing options...
Soop Dogg Posted April 8, 2008 Share Posted April 8, 2008 Sounds more like the battery not holding a charge properly to me, if its showing just over 12V after a drive but going down to 10V after sitting, if there was a problem with the alternator it wouldn't charge as a rule, you really need to put a meter on it to be sure, a good check is if its showing over 14V when running then its very likely to be the battery. There's more to the alternator than just the charging bit. The voltage rectifier/regulator is contained within the alternator. If the diodes break down within this it causes the battery to drain as described. Normally, the diodes work kind of like a one-way valve, allowing the current flow from the alternator to the battery when the car is running, thus charging the battery. When the engine is turned off, no current can flow back the other way, so the battery keeps its' charge. If the diodes fail, current is allowed to leak from the battery to earth, so the battery goes flat. On many alternators, you can replace just the 'diode pack' rather than the whole alternator. (I haven't checked if this is possible with the Supra alternator, but I'd guess it would be) Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted April 8, 2008 Share Posted April 8, 2008 Charge it up and leave it disconnected overnight, reconnect, if it starts something's draining it, eight times out of ten it's an (aftermarket) alarm fault, IMO. Quote Link to comment Share on other sites More sharing options...
Tricky-Ricky Posted April 8, 2008 Share Posted April 8, 2008 There's more to the alternator than just the charging bit. The voltage rectifier/regulator is contained within the alternator. If the diodes break down within this it causes the battery to drain as described. Normally, the diodes work kind of like a one-way valve, allowing the current flow from the alternator to the battery when the car is running, thus charging the battery. When the engine is turned off, no current can flow back the other way, so the battery keeps its' charge. If the diodes fail, current is allowed to leak from the battery to earth, so the battery goes flat. On many alternators, you can replace just the 'diode pack' rather than the whole alternator. (I haven't checked if this is possible with the Supra alternator, but I'd guess it would be) Thats why i said to put a meter on and do the basics first, its just confusing for people to just go into all the details straight off, i was going to suggest the same as Chris, once they had replied;) Quote Link to comment Share on other sites More sharing options...
Pete Posted April 8, 2008 Share Posted April 8, 2008 Charge it up and leave it disconnected overnight, reconnect, if it starts something's draining it, eight times out of ten it's an (aftermarket) alarm fault, IMO. Leave it in the cold though as you may find that's why in the last two days it's been affected. I had to replace mine this last winter for not holding a charge. If you have a multimeter you can check the voltage drain with ignition off, should be very slight. Quote Link to comment Share on other sites More sharing options...
turbonut Posted April 8, 2008 Author Share Posted April 8, 2008 Hi chaps Back at base with the supra. Yes, I checked the charge with the ignition off when it wouldnt start, when it was just over 10V. They started it by hooking leads to the flatbed. got it to the garage, they then called me a few minutes later. Apparently the immobiliser needed to reset (?), they used the 'stick' in the socket under the dash and it started up. However, after driving it 20 miles, long enough to get some charge into the battery, switched it off and restarted it. Still sluggish to turn over. will check voltage again tonight. Soop dog - that sounds about right. I'll check the battery again in the morning. Chris - given the problem with the immobiliser thats possible too. Its become more and more reluctant to turn over in the last 10 days so its been ongoing rather than sudden. Is it possible to change the diode pack with the supra do you know? thanks again guys Lx Quote Link to comment Share on other sites More sharing options...
TrickTT Posted April 8, 2008 Share Posted April 8, 2008 Hi Lin, good to see you back on the forum again:). You need to do a current drain check on a known good battery to see how much current is being drawn when the car is switched off and the alarm active. You should see less than 0.1amps. Any more and somthing is not right with the wiring. Have you changed anything on the car recently? Quote Link to comment Share on other sites More sharing options...
supra_surj Posted April 8, 2008 Share Posted April 8, 2008 I had same problem. Mine turned out to be my headunit. It developed a fault and was draining the battery. An auto electrician checked the voltage of the battery while pulling the fuses out one by one and noticed the drain from the stereo. Quote Link to comment Share on other sites More sharing options...
turbonut Posted April 8, 2008 Author Share Posted April 8, 2008 Yep, definitely something draining the battery, was doing same thing to the previous battery so looks like an autoelectrician tomorrow Have to cancel getting my wheels refurbed and the spats resprayed now Lx Quote Link to comment Share on other sites More sharing options...
Soop Dogg Posted April 8, 2008 Share Posted April 8, 2008 Thats why i said to put a meter on and do the basics first, its just confusing for people to just go into all the details straight off, i was going to suggest the same as Chris, once they had replied;) No probs Rick. You just didn't seem to notice that in the original post by Turbonut, it was said that the battery had already been changed. That's why the suggestions were heading towards alternator. Quote Link to comment Share on other sites More sharing options...
Tricky-Ricky Posted April 8, 2008 Share Posted April 8, 2008 No probs Rick. You just didn't seem to notice that in the original post by Turbonut, it was said that the battery had already been changed. That's why the suggestions were heading towards alternator. Actually no i didn't:innocent: doh! Quote Link to comment Share on other sites More sharing options...
SupraStar 3000 Posted April 8, 2008 Share Posted April 8, 2008 Sorry your having issues Linda. I'm sure you'll be back on the road soon. Can't really offer anymore help than the others have do so already. Good luck. Quote Link to comment Share on other sites More sharing options...
turbonut Posted April 17, 2008 Author Share Posted April 17, 2008 It got sorted btw. turned out to be a faulty battery after all Took it to an auto electrician who ran full checks on alternator, starter motor, leads and connections etc, all sound Checked the battery - only 9.5 V standing charge, wouldnt hold the charge, some gas in there too. Took it back to Halfrauds who were v surprised but changed it, after I made them check the voltage on ALL their HCB005 batteries Worked fine after that tho the immobiliser still playing up thanks all for your suggestions Lxx Quote Link to comment Share on other sites More sharing options...
marc_p Posted April 17, 2008 Share Posted April 17, 2008 Good to hear Quote Link to comment Share on other sites More sharing options...
turbonut Posted April 17, 2008 Author Share Posted April 17, 2008 Good to hear cheers mate, don't know anything about immobilisers do you?? Quote Link to comment Share on other sites More sharing options...
marc_p Posted April 17, 2008 Share Posted April 17, 2008 cheers mate, don't know anything about immobilisers do you?? Erm.......I know that there a b@stard when they go faulty, but apart from that erm....no, sorry:( Quote Link to comment Share on other sites More sharing options...
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