Club Cobra

Club Cobra (http://www.clubcobra.com/forums/)
-   Shop Talk (http://www.clubcobra.com/forums/shop-talk/)
-   -   alternator reads 10.5 volts? (http://www.clubcobra.com/forums/shop-talk/65295-alternator-reads-10-5-volts.html)

kmarccoco 06-11-2005 10:09 PM

alternator reads 10.5 volts?
 
i just replaced my battery thinking it was from sitting. i think my new one is loosing power. i hooked up a volt meter to positive post and it reads 10.5 volts. wierd thing, when i disconnect wire from positive post, and then check volts it reads 14.2 at 800 rpm. why does the volts weaken when the positive wire is connected? it also reads 10.5 volts at the battery posts. is it a bad alternator, or some ground problem???

strictlypersonl 06-12-2005 04:19 AM

That battery is currently very dead! A flat battery will naturally reduce the net system voltage when it's connected to the alternator but I suspect that your alternator is also bad.

I would first charge the battery fully so that it's not part of the equation. Once it's charged, check its voltage under load - turn the radiator fan and lights on. You should still see 12-12.5 volts. Less than that indicates a bad battery.

Next, check the voltage regulator. Make sure that the case is grounded through the black wire. Use this guide (page 8) to bypass the regulator.

I suspect that the alternator is cooked.

kmarccoco 06-12-2005 04:24 AM

the alternator has a bigger pulley too. there was black dust on the front of the alternator near the fins.... thanks for the info...if i put a new alternator on, will it rechargs battery. i just bought the battery last weekend. its a optima gel...

strictlypersonl 06-12-2005 05:46 AM

I would still try to charge the battery before I replaced the alternator. Otherwise, you'll have to jump the car from another source to get it started. I don't like the idea of putting the new alternator at full load immediately with a dead battery - just a superstition of mine though.

Ron61 06-12-2005 05:48 AM

If the battery has no bad cell or cells and is not to far down, yes, a good alternator will recharge it but you may have to drive a while depending on how far down it is. If it sets a lot get one of the $39.95 Battery Tenders fromNAPA or any other parts store and connect them when it is setting. I have used them for many years and have never had a dead or low battery as they will kick on and keep it at peak charge and also just to move the electrolite from time to time.

Ron :)

chopper 06-12-2005 06:13 AM

Second what Mr. Widener said. Optima gel-cell batteries will not take well to a standard charger, even one of the low-amperage types. You need something like a Battery Tender to charge them without frying the battery. As he further points out, the Battery Tender also has a set of terminals which you can permanently mount to the battery terminals and then plug the charger into while the car sits. It will keep the battery at full charge during those periods when it just sits.

kmarccoco 06-12-2005 12:06 PM

right on , thanks for the info.. bettery tender it is... and alternator.

kmarccoco 06-12-2005 12:28 PM

when i checked the voltage at the regulator switch(mentioned above) it read 10 volts or so. is it supposed to read 11.5. could that be the problem? what fuse is the regulator fuse?

strictlypersonl 06-12-2005 03:51 PM

The voltage at the regulator will never read above the battery voltage (unless there's been some kind of divine intervention...).

The voltage regulator's power comes from the top fuse on the driver's side.


All times are GMT -7. The time now is 04:31 AM.

Powered by vBulletin® Version 3.8.0
Copyright ©2000 - 2025, Jelsoft Enterprises Ltd.
Search Engine Friendly URLs by vBSEO 3.6.0
The representations expressed are the representations and opinions of the clubcobra.com forum members and do not necessarily reflect the opinions and viewpoints of the site owners, moderators, Shelby American, any other replica manufacturer, Ford Motor Company. This website has been planned and developed by clubcobra.com and its forum members and should not be construed as being endorsed by Ford Motor Company, or Shelby American or any other manufacturer unless expressly noted by that entity. "Cobra" and the Cobra logo are registered trademarks for Ford Motor Co., Inc. clubcobra.com forum members agree not to post any copyrighted material unless the copyrighted material is owned by you. Although we do not and cannot review the messages posted and are not responsible for the content of any of these messages, we reserve the right to delete any message for any reason whatsoever. You remain solely responsible for the content of your messages, and you agree to indemnify and hold us harmless with respect to any claim based upon transmission of your message(s). Thank you for visiting clubcobra.com. For full policy documentation refer to the following link: