Do you do it on the back of it ? I assume that would be the best but figured I'd ask to be sure. Mine went last week and took the battery with it and I just want check it. Also how much should I read on the meter ?
Where to measure alternator output
- Thread starter They call me Pete
- Start date
You can check it at the battery since it is connected directly to it. You should get around 13.7 volts with the engine running at idle.
Are you sure the battery didn't take out the alternator?
Are you sure the battery didn't take out the alternator?
ptschram
Well-known member
I'd look for a minimum of 13.7 at idle, anything less is suspect.
Have you replaced the battery, or the alternator? If neither to either (I had to try to use that word progression!), STOP! and replace one or the other. Perhaps a good idea might be to describe what happened before we go further.
Have you replaced the battery, or the alternator? If neither to either (I had to try to use that word progression!), STOP! and replace one or the other. Perhaps a good idea might be to describe what happened before we go further.
I think it was the alternator that took the battery with it. Tach would work sometimes and other I'd drive down the road about a mile or so and all of a sudden it would start working. From what I read on hear sounded like alt. went south. I replaced both battery and alt. together. Also battery wouldn't get charged/hold one after a half hour or so of running. I went with the alt. due to wacky tach but it could have been the battery. I chose to just replace both. Dumb, maybe but at least I have a piece of mind and everthing is fine now. I just want to double check alt. I've read some people getting junk remans and want to make sure mine is good
thanks
thanks
Well I checked it this afternoon and it's only putting out around 12.3 but I noticed my serp. belt is getting shredded on one side. It seems to be running in the middle of pulleys but I'm going to see if one of the pulleys is worn. I'm going to replace the belt and see if I can get closer to the 13.7. Supposedly the alt. was checked before I bought it and to add insult my tach is dead :banghead:
ptschram
Well-known member
Your tach is dead because your alternator is dead. The signal for the tach is derived from the alternator.
I would agree with you but after two days of starting, running wipers, heater fan, headlights, radio and ect. I think the battery would have died by now. Could it be a bad ground/ect. causing tach not to work or is it cut and dry no tach alt.dead ?
I drove roughly 200 miles on the battery only (alternator died on the way there, I had to come back).
Of course, with headlights, that's much shorter. I drove roughly 15-20 miles with headlights on (night) and no alternator. [That was not very smart since.... You don't decide when you can/have to pull over when the battery is too weak to power even just the engine]
Of course, with headlights, that's much shorter. I drove roughly 15-20 miles with headlights on (night) and no alternator. [That was not very smart since.... You don't decide when you can/have to pull over when the battery is too weak to power even just the engine]
Now if your alternator is on it's way out/limping, it might still be charging/producing some courant (but not enough) but the feed to the tach might be dead (IIRC, it's the output of one of the diodes).
That's my thinking too. Alternators can kinda work but not quite good enough. Often, it's not a live and dead state, they will go through a "I'm on my way out" state (like one then two diodes will fail leaving 1 or 2 working).ptschram said:
MUSKYMAN said:
Most times I've seen a voltage regulator go it went opposite and overcharged and nearly exploded the battery. Either way you can change just the voltage regulator quite easily, just remove the plastic cover on the alt and there she be.
Cheers,
Mike
There could also be blown diodes and shorted winding.
My 95 SWB's alternator failed likely due to a shorted winding last week.
My 95 SWB's alternator failed likely due to a shorted winding last week.
Hey Mike,flyfisher11 said:
Were would you order the part? When mine died, I gave it to a local shop because I could not source a regulator!
As you said, it's quite simple a single component in there to screw/unscrew.
MonLand said:Hey Mike,
Were would you order the part? When mine died, I gave it to a local shop because I could not source a regulator!
I just googled until I found one. You can also search your local area for alternator rebuild shops and see if they won't sell you just the VR. I think I paid around $90 for mine.
Probably different animal but my D2 alternator went south a few months back.
My idiot light came on while driving. I took the brush pack/voltage regulator off. The brushes were pretty much gone but the real problem was that the brushes had worn away the armature(hope I'm using the right term) big grooves in it. I was forced to buy a brand new one(no rebuilds for me please).
Another thing that I thought was odd was that according to all data and the rave. The alternator only needs 3 volts to turn off the idiot light.
Just another reason to not take any of the D2 idiot dash lights seriously.
My idiot light came on while driving. I took the brush pack/voltage regulator off. The brushes were pretty much gone but the real problem was that the brushes had worn away the armature(hope I'm using the right term) big grooves in it. I was forced to buy a brand new one(no rebuilds for me please).
Another thing that I thought was odd was that according to all data and the rave. The alternator only needs 3 volts to turn off the idiot light.
Just another reason to not take any of the D2 idiot dash lights seriously.
Well I'm pulling it out today and going to have it tested. The damn thing is only a week old and I don't want to compromise my new battery. I just hope I don't have to change out three to find a good one like some of the stories I read on here :banghead:
According to NAPA it was fine but they gave me a new reman anyway. The guy wasn't to happy but he did it anyway. The saga continues :banghead: