Can I replace the alternator myself? or maybe it isn't the alternator

[SHO&'Vette]

I'm back with another question for the experts ... I got the transmission replaced in the SHO, by the way, and that part is great. as it turned out, I had mechanical breakdown coverage on my auto insurance and GEICO very graciously paid for a new trans. Lucky for me. I now have another problem. The battery was dead a few weeks ago (I think my daughter was 'parked' with the radio running but I can't be sure) and I bought a new battery. It went dead within 2 weeks. I can jump start the car but even after running the engine for more than an hour and driving around some, the battery did not charge up. Volt meter showed less than 11 volts. Is there anything I should be looking for besides a bad alternator? If it is the alternator, do you think I can replace it myself. It looked fairly accessible and I have tools (unless there is some specialty tool I would need). Also, I pulled the codes and got a couple of messages - I'll deal with that in the next message - but none of them seemed to implicate the alternator. Is there a code which would give an indication of what might be wrong? Thanks for your help.

 

[KazMan]

the alt may work but cant the battery may not hold a charge if its no good.

with the car running put a volt meter on it.

it should read ove 14volts at idle with the car running. If it doesnt then its your alt. If it does then Id say battery.

 

[BlackOnBlackATX]

well the alternator wont throw you any codes so your kinda in the dark that way, but a sure fire test is once the car is running pull the cables off the battery. if it stops running your alternator is hosed. and you should have your battery checked at an autozone or a pepboys or somewhere similiar. i hosed my alternator by playing my stereo without the car running for too long. i have a large amp and the volt regulator couldnt stay steady since i sucked so much out of the battery so it gave out. oh well ::shrugs::

ok now if you have to do it yourself its really not that bad. I recommend removing the battery AND battery tray seeing as if you have big hands such as myself it makes life easy to get in to manipulate the belt tensioner nut. this way you can squeeze your whole sholder into it to use your body leverage to push on it. but youll only need 3 different size sockets i think and a 3/4 inch wrench for the tensioner ( i think it was 3/4) ive done mine twice and i can do it in about 30 min total, removal with installation, give or take 5 minutes. good luck!

 

[projectSHO89]

If the alternator isn't putting out anything, the BATTERY light should be on. Does the light come on when the ignition is first switched to RUN (before it is started)? If it doesn't, the bulb is probably burned out and you're missing an indication that you aren't charging.

Don't do the trick of pulling the battery cable off while the engine is running. If you do, you run a great risk of frying something electronic. Your choice.

Get an external charger, plug it in overnight, then test the system with a meter in the morning. Sears sells an inexpensive digital meter for around $20, an analog one for around $12.

Steve

PS Disregard any codes until the electrical system is fixed. Any codes you've presently gotten may be bogus due to compromised electrical system integrity.

<small>[ December 31, 2002, 06:45 PM: Message edited by: projectSHO89 ]</small>

 

[SHO&'Vette]

Thank you for the advice ... the BATTERY light did come on when I last tried to start it and after I had jumped it from my husband's Tahoe (while I was trying to pull the codes), it was running for about 20 minutes while still hooked up to his car (which might not have been such a good idea but it's done). Afterwards, it started on its own twice (no jumper cables) but it wouldn't start the third time. I don't think it's a bad battery. It's brand new top of the line SearsDieHard and they tested it in the shop before they put it in three weeks ago. I guess that leaves the alternator. I saw a rebuilt alternator on the Cincy Sho parts list for $175. Do you think that's a good price or should I shop around some more. Thanks again for the help.

 

[luigisho]

I would shop around. See how much a quality rebuild is to have done locally or how much for one from AutoZone. I would get it tested a little further before you commit. Get the alt. output and battery tested. Places like autozone have testing equiptment available and will do it for free.
New batteries can be defective from time to time. If you have mechanical aptitude you could probably replace this yourself.

Tip for future posts. You can make a "signature" that appears at the bottom of your posts. Please include the year and configuration (MTX for manual or ATX for automatic transmission) there are a few differences that make diagnosing certain problems easier.

 

[BlackOnBlackATX]

yeah, ive seen em cheaper than $175, i would go to autozone and pay the $140 i think it was because its also lifetime waranteed. i would recommend against rebuilding only because i had mine rebuilt for $100 bucks over the summer only to have a different component blow that wasnt replaced since it was in good condition at the time of the first rebuild. this just costs more sometimes. not to say rebuilding is a bad idea, but not *always* cost effective. but im sure you can get one for cheap, keep lookin wink

 

[rangerj]

SHO and Vette,

If Sears put a new battery in the car, they tested the charging system, right?

Before you replace the alternator, I suggest that your charging system, i.e. the alternator, be tested. You can remove the alternator and have it tested at most auto parts stores. I think Auto Zone will test it for free, in the car.

It is possible that your "new" battery will not hold a charge. It happens. Sears should test the battery for free, and may even test the charging system for free, or a small fee.

Next, if the battery is good, and the alternator is charging, then your battery is being drained by a short, or something that is "on" and drawing electricity, such as the glove box light, or the trunk light, or the under hood light.

If you find this to be the case, you will need to do an amp draw test to confirm it. This takes an electrial "multi-meter" that can measure amps being drawn from the battery (also available from Radio Shack or Sears, etc. About $35).

You remove the fuses, one at a time, untill you find the circuit that is drawing current. As mentioned above it is frequently a glove box light, trunk light, or under hood light, that is stuck in the "on" mode. It can be a shorted switch, or just a switch in need of adjustment.

Lastly, I believe that you asked if you can remove and replace the alternator yourself. With a few metric wrenches, and a 5 mm allen key wrench, and a willingness to try, YES you can.

It's just a matter of removing a few nuts and bolts, unpluggig a wire connection, and reversing the process to put it back together.

If you do not have service manuals with pictures and a description of the process, you can usually find them at your local library in the referrence section.(Motors Manual, Mitchels, Haynes, and others) You also have access to hundreds (or more) of experienced SHO owner/mechanics at this web site.

Radio Shack has a "Automotive Battery and Alternator Tester" for about $15 (if I remember right). The only part numbers I can find on it are 22-112. rangerj