Intermittent Power Problems

[Carrots]

After having a vintage air system and electric fan installed I began to have battery power problems. If the car was left untouched for a few days then it wouldn't start. Even when driven it would typically last a week and then die. It would jump, start and run until you turned it off and tried to restart it and then nothing. The battery looked old and was kinda small (600) but I borrowed a charger and left it overnight on a slow trickle. Next day it started and ran and was OK for a few days until the same thing happened again.  I bought a new heavy duty battery (800) and once again all was well. Then one day it wouldn't start again (Ignition clicks, low-fi alarm &c, dead battery once again). I had checked the alternator and that was working so I replaced the voltage regulator. Success and I had no problems again for a few days. However it's just died again after taking us out to dinner. That was about a 25 mile round trip and I did a few miles earlier today as well. So the car is getting use, and is generally running OK in between all of these dead battery issues.  I can't think of anything else to check.  I've been living with this for about a month now and kinda used up the good graces of mobile mechanics, local shops and neighbours with jump leads. It even died when I took it for a wash. Triple A has saved me twice. Autozone once. I've seen the $59 jump start man three times thus far as well. Given that the battery is new, the alternator is working, the voltage regulator is new and its being driven why does it keep conking out on me? Sure I'm expecting to run the car, the a/c, the radio, the alarm &c but it shouldn't be that hard for it to keep up should it? I got the biggest battery I could. The lights and radio are still working right now but there is not enough umph for it to turn over and start. I've put 150 miles on it this week (the first bit of trouble free motoring I've had for a while ho ho ho) and just can't fathom what could be causing this. I'm going to be working again soon and this is liable to turn from an annoyance into to a big problem.  Its a week today since I replaced the regulator and recharged the new battery, the connections and cables are all fine as far as I can tell. Does this sound like a starter relay/motor problem? She can be a pig to start, especially after a run but not sure if thats part of the same problem I have here or another little gremlin (1st thing from cold starting is much easier than when warm) The fact that there is still enough power to light the lamps / set the alarm now but not enough to start the car boggles my mind even further. So far I've either had power or not had power but I now seem to have a bit of power but not enough to do the necessary. Help!  Thanks folks

[charger Downunder]

Id say time for a starter rebuild or new one.Check your earth leads from battery to body make sure its tight even take it off and sand the contact areas.

[FLG]

Check your cables, could very well be a bad ground or bad contact somewhere.

Also, if you turn on your lights when it dosnt start, how much do they dim when you go to crank it?

[Carrots]

Thanks chaps. When I went out this morning the alarm would still arm/disarm and the radio would work (although it had lost its presets). Now its totally dead - no lights, radio and just a click when I try and start. Its telling me dead battery, but there is no good reason for that to be the case again. As I have starting issues anyway I'll probably swap the motor & relay (will autozone have these?) but I'm not sure how helpful that will be as I think this has to be a power problem of some sort and I don't think either starter bit has an effect on power generation / leakage (or does it?) As this has been rather reccuring I've already cleaned up the connections. eek

[FLG]

How many volts do you get at the battery with the car running?

[Carrots]

I'll need to find someone to give me a jump before I can check that out, but it was lower than I expected with the old battery and then better when I put the new one in. So far I've been running down the list of potential causes/problems one by one and seeing what if anything solves the problem. First I checked the cables and connections, then checked the alt, then replaced the battery, then the volt. regulator. All of which hasn't helped. I'm running out of things to try, but hope to get it jumped later today and then check the voltage. Are there any other bad 'part's that could either be draining or discharging or just not charging the battery? 

[Carrots]

In order to try and be sure that I do have a drain problem as opposed to something else I've just taken the new battery back to AZ to get it tested. Whilst unlikely I wondered if I'd killed a cell in it before changing the regulator.  As I'd only just bought this battery they wern't  interested in testing it and just swapped it for another new one. So now all is well again and everything works. So I think my starting issue is a separate problem. However having been here before I'm expecting this new battery to go flat again unless I can work out what is causing this high pull from it. I have some helpful neighbours but this seems to be one of those suck it and see situations where finding the bug could take some time.  I'd be tempted to take it somewhere Monday if I could tell them anything more than I have a power drain. That said I don't have a voltage meter so not sure what else I can do with it....

[FLG]

Carrots,

Buy a digital volt/amp meter, it will come in handy down the line.

Test your voltage at the battery while running. You should see around 14 volts. If you are getting that, you now know the alternator is charging.

Next step, turn the car off and put the meter on amperage. Unhook the positive cable and put one end of the meter on the lead, the other on the battery. If you have any considerable drain, you will see it on the meter.

Finally. Dont overlook the Amp meter for corrosion on the posts. And unhook the battery before you begin to clean them if there is any.

[71_deputy]

sounds like a diode in the alt is discharging your battery.

out of the six diodes in the alt- it only takes one to discharge a battery- alt still can put out juice with one shorted!!!

John Mac

also check to see if a trunk, glove box or a delay light is on all the time!!!!

[darkfiire5000]

You have a parasitic drain it sounds like, something that is electronic or runs off electricity is drawing current after your key is off. Do an amperage test on the battery if it is above a tenth of an amp you got one. 

[Carrots]

Thanks Chaps. I've checked the trunk / glove box lights and nothing is on when it shouldn't be. I'm off to get myself a meter. Will report back later....

[Carrots]

OK, I'm getting 12.55 volts whilst running just the engine. Then 12.30 with engine and A/C on, 12.25 with engine, a/c & radio and finally 12.15 with engine, a/c, radio & lights.

All of these numbers were when on a flat idle.

It's only slightly higher (12.65) with everything off and the keys out 

I did an amp test on the alt and that is putting out at the gauges max level (75)

So if the alt is putting out why am I between 1-1.5 lower than I should be voltage wise? Should that amount matter? The battery has been on 24 hrs now..........

[FLG]

That alt isnt charging. You should be seeing around 14 volts at the battery while running.

[Carrots]

Okey dokey, I've been told 14 by some other folks today and so as that is the consensus I'll swap it out. I've heard horror stories regarding cheap alts from AZ / Napa though and so wonder if any of you have a recommendations for both amp size and a reasonable brand?

I've found these http://www2.partstrain.com/store/index.php?Ntt=Alternator&N=1607+10113+4294966721+11921 but wonder if I should be looking at a 75 amp as a minimum? These are 60's. I have a '72 with a '67 383 and as above will be using the a/c & electric fan, cd player, alarm and lights all at once on a fairly regular basis. I'd rather over do it than the other way round but 100 would appear to be too much? (not to mention expensive). Thanks folks, appreciate it.

[FLG]

You might have a 67 engine but you SHOULD have a 72+ alt. Older alts used a different regulator. There should be 4 wires comming off of your alternator (green, blue, black, and red?). So id go with a alt from a 71 charger. Check out www.Rockauto.com for good prices.  The thing with napa alts is that there cheap reman, some work great others people have problems with.

[Carrots]

10-4 Sir, and a 75+ ?

[Carrots]

Well I've had the alt rebuilt and its now putting out a little over 100 amps. I'm still getting a reading of less than 14 on idle (now up to 13.5 though) so its time to suck it and see.
Thank you all for your help thus far.

[FLG]

How about with a little rev?

13.5 is fine as long as it stays at about that at idle.

[Carrots]

Just a little update to say that I've had no battery problems since having the alt rebuilt 4 or so weeks ago. I now have a P/S fluid leak to deal with. Happy days 

[71_deputy]

10-4 Carrots!!!!!!


I too have to deal with the box leaking and the pump is starting to go!!!!!

oh well- winter is almost here!!!!