SpecialWarr Posted March 11, 2016 Share Posted March 11, 2016 As you may have read elsewhere, my starter died a couple of weeks ago, so I had it replaced at a garage. When I got it back it drove around fine until the beginning of this week when it appeared that the battery was dying. I replaced it with a new one under warranty at Canadian Tire on Monday and have been driving it around since then with only one strange issue: I have had the meter in the dash reading 13.6 - 13.8 volts since Monday. The rebuilt alternator that I bought 18 months ago didn't look bad and definitely had power going to it (sparked pulling off the power wire... oops... grounded that wrench for a second!). Which brings me to the question at hand: since the starter, alternator and battery are all new.... how is it that I have only 9.8 volts between the terminals on the battery after 4 days of driving around? any things I should have looked at and didn't, broken grounds didn't really make themselves apparent since there were only 4 cables to undo and reattach and they all appeared good. Oh masters of the electrical diagnostics bestow upon me an answer please!! I pay beer! Link to comment Share on other sites More sharing options...
k9sar Posted March 11, 2016 Share Posted March 11, 2016 First, it is completely possible that the battery is bad. It can happen. It should be taken to a shop or parts store and bench tested. Another way to see if there is a bad cell is to make sure it is at full charge, throw a voltmeter on it and see what the voltage is on draw down while starting. It should not be below 10v while cranking. Make sure you are testing terminal to terminal, not on the clamps. This is the only true way to read the battery. If the voltage drops below 10V, the battery is low in charge (which is why you should start with a full charge, low in water (though most batteries nowadays are maintenance-free and you should not have to add water, or your internal resistance is too high (bad cell, needs to be replaced) Then, connect your voltmeter from clamp to clamp and check the voltage again during start. Your reading should be within .1V as the prior test. If not, you should pull the clamps, clean the terminals and reinstall, then repeat the test. Third, connect the meter to the positive cable at the starter and to case ground and repeat the test. You should not have a variance of more than a half volt. IF you do, you probably have a bad cable or something else in the flow that is causing resistance (bad relay, whatever) As for the alternator, 13.8 is the bare minimum you would expect to see while running. It should be more like 14+. You can test the alternator by connecting your meter to the battery posts, start the car and let idle. Turn on the high-beam headlights and check your voltage. It should be between 13.8 and 14.5. Then, if you increase your revs to 1500rpm, you should be reading between 14.2 and 14.6. If not, the alternator may have bad diodes. Then turn off the headlights and check the voltage again (still at 1500rpm). If your voltage exceeds 14.8, you probably have a bad voltage regulator in your alternator. Also, you mention that "the starter, alternator and battery are all new"... Do you trust that your 'shop' used a new starter and not just one that was returned, possibly defective? Starters can also be bench tested but they are a pain in the ass to remove. The alternator is a rebuild and, based on the voltage output, I would suspect that is a problem. Hope any of this helps Link to comment Share on other sites More sharing options...
Lemay Posted March 11, 2016 Share Posted March 11, 2016 I would test the battery first, a load test or what I prefer if you have the time is to get the battery fully charged. Let it rest 5-7 day and check voltage. If it's dropping the bat. is not holding it's charge. If it's hold the charge I would reinstall it in the truck but not driving it for few days. Check the voltage and you will find if you have a battery drain on the truck. some years ago I got 2 bad battery in a row at Canadian tire, so bad battery even if it's new can append! 2 Link to comment Share on other sites More sharing options...
k9sar Posted March 11, 2016 Share Posted March 11, 2016 that too. Link to comment Share on other sites More sharing options...
adamzan Posted March 11, 2016 Share Posted March 11, 2016 One thing I would like to add is to make sure you always verify with a voltmeter at the battery. Don't rely on the dash gauge, as it may not always be accurate. Link to comment Share on other sites More sharing options...
Terranovation Posted March 11, 2016 Share Posted March 11, 2016 When I had all my battery problems I first thought it was the battery so I got a new battery and it was only charging at 13.8 volts so I drove around like that for a year then suddenly I had a flat battery again after it was very hard to start the engine. Then I knew it was the alternator. Tried at a few electrical places to see if I could get it rebuilt but they all said a rebuild would cost as much as a new alternator so it wasn't worth it so I ended up buying a new alternator which I luckily found on ebay for $400 cheaper than what I was originally told. Now it charges initially at 14.5 volts maximum, 14.3-14.4 normal driving. Lights on: 14.2-14.1. Lights on and aircon/fan on: 13.8 volts. Battery at rest: 12.6 volts. Link to comment Share on other sites More sharing options...
SpecialWarr Posted March 11, 2016 Author Share Posted March 11, 2016 I always test both on the top of the battery terminals and off of the clamps before I do anything electrical. I had a full charge into the battery before I installed it this morning, installed a new ground wire for the alternator after, started it up, backed it up a couple of parking spots and checked voltage at the battery terminals... 8.90v.... checked the alt case to the positive terminal.... 10.23v while running. I just pulled the terminals off and check voltage my meter reads 1.483v... then I switch the range and it reads 8.92.... are you thinking what I'm thinking? Link to comment Share on other sites More sharing options...
silverton Posted March 11, 2016 Share Posted March 11, 2016 You can test for an electrical drain by disconnecting your negative terminal, and probing the post and the clamp with a voltage meter. http://www.wikihow.com/Find-a-Parasitic-Battery-Drain Link to comment Share on other sites More sharing options...
SpecialWarr Posted March 11, 2016 Author Share Posted March 11, 2016 (edited) And a $35 analog multi-meter solves the problem..... the digital one is is need of maintenance. Digital reads 8.9v.... analog 12.6 on the terminals, 14.7-ish running and 13.7 with high beams, lights, every switch and light on with the wipers running..... problem? crappy tire digital multi-meter!! Saved by Rona Hardware store analog meter! Although I'm sure the ground that I made for the alternator case was helpful... somehow. Now to clean up the inside of the truck and the living room. Edited March 11, 2016 by SpecialWarr 2 Link to comment Share on other sites More sharing options...
SpecialWarr Posted March 11, 2016 Author Share Posted March 11, 2016 Thanks for the help guys... I really appreciate the gurus that help out!! You guys rock! Link to comment Share on other sites More sharing options...
Terranovation Posted March 12, 2016 Share Posted March 12, 2016 Phew! Lucky you! Have a lucky 4 leaf clover. Link to comment Share on other sites More sharing options...
SpecialWarr Posted March 14, 2016 Author Share Posted March 14, 2016 Yep, that clover, my guardian angels and the 3 lives that I have left over are all on duty full time! Thanks again, you guys know I really have no electrical skills at all so without my support network (haha!) I would be lost.... AAnnd I still owe adamzan a call! Link to comment Share on other sites More sharing options...
adamzan Posted March 14, 2016 Share Posted March 14, 2016 And a visit. 1 Link to comment Share on other sites More sharing options...
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