Posted By: SeventySatellite
Is this a good Alternator test ... - 10/29/11 01:55 AM
I read this somewhere awhile back but I haven't tried it yet. Remove positive, hold it above post, if car dies then it's a bad Alternator.
Is this a good Alternator test ...
Posted By: CrAlt
Re: Is this a good Alternator test ... - 10/29/11 01:58 AM
No thats a bad idea..
If the regulator is bad then you could fry everything in the car.
Just get a volt meter and test it the right way.
If the regulator is bad then you could fry everything in the car.
Just get a volt meter and test it the right way.
Posted By: SeventySatellite
Re: Is this a good Alternator test ... - 10/29/11 02:09 AM
Thanks 
Posted By: RodStRace
Re: Is this a good Alternator test ... - 10/29/11 02:57 AM
Wrong/bad/dumb way.
RIGHT WAY
Ensure battery is fully charged.
Load test battery to make sure it's good.
Install battery in car with good clean connections.
Inspect alt., belt, mounts, wiring and regulator. Fix as needed.
Perform starting draw test.
Fix as needed.
Start car and do a charging system test with a heavy load tester.
Fix as needed.
That's why people do the disconnect thing. It's quick and easy. It does NOT check all the components and circuits like you should, and it can cause damage.
RIGHT WAY
Ensure battery is fully charged.
Load test battery to make sure it's good.
Install battery in car with good clean connections.
Inspect alt., belt, mounts, wiring and regulator. Fix as needed.
Perform starting draw test.
Fix as needed.
Start car and do a charging system test with a heavy load tester.
Fix as needed.
That's why people do the disconnect thing. It's quick and easy. It does NOT check all the components and circuits like you should, and it can cause damage.
Posted By: PHJ426
Re: Is this a good Alternator test ... - 10/29/11 03:23 AM
I don't own a load tester so I have also tested the charging by turning on all the electrical loads ie. high beams, wipers, radio, heater blower motor full speed, hazards etc all on.
Measure the voltage at idle and then I would run the rpms up slightly and measure the voltage as well.
Measure the voltage at idle and then I would run the rpms up slightly and measure the voltage as well.
Posted By: cornet684me
Re: Is this a good Alternator test ... - 10/29/11 05:05 AM
that is how Chevy guys check their Alternators, 
get a meter and check it the right way
get a meter and check it the right way
Posted By: lahatte
Re: Is this a good Alternator test ... - 10/29/11 05:43 AM
Recommendations for a meter?
Posted By: CYACOP
Re: Is this a good Alternator test ... - 10/29/11 12:44 PM
Open hood and and use a regular volt meter and check battery voltage. Start car and check with it running. If it goes up chances are its charging, Rev up a little look for increased voltage.
Posted By: DANA60
Re: Is this a good Alternator test ... - 10/29/11 01:06 PM
with that way, and you can also put a tester directly to the alt. (big balck wire) and see what that voltage is. Or, you can pull your alt. and take it to, say, Auto Zone, who will check it for free. Battery is good I assume?
Posted By: Bad340fish
Re: Is this a good Alternator test ... - 10/29/11 01:16 PM
I did that quick and easy test once in high school. My car(barracuda) was running with the headlights on, I pulled the cable and the car started to die so I put it back on. That was dumb lol, it burned out every single light bulb in the car that was on other than the tach light(autometer). Evidently the regulator told the alternator to go full steam and when the battery was hooked back up it caused a voltage spike. The only lights that worked after this were the turn signals, brake lights, and high beams, the only lights not turned on at the time.
I spent a good chunk of change at the parts store for all the lights.
I recently canned the mopar charging system. I put a GM CS130 alternator on the car. Now with headlights, electric water pump, fuel pump, and fan it idles at 13.9 volts. Thats with a 5" crank pulley even.
I spent a good chunk of change at the parts store for all the lights.
I recently canned the mopar charging system. I put a GM CS130 alternator on the car. Now with headlights, electric water pump, fuel pump, and fan it idles at 13.9 volts. Thats with a 5" crank pulley even.
Posted By: RapidRobert
Re: Is this a good Alternator test ... - 10/29/11 02:51 PM
Quote:I have the diagram to hook that one up. is there a special year/make to ask for and will some spacers and fabbing a simple bracket mount it or does it need a custom bracket
I recently canned the mopar charging system. I put a GM CS130 alternator on the car.
Posted By: DAYCLONA
Re: Is this a good Alternator test ... - 10/29/11 03:00 PM
Quote:
I read this somewhere awhile back but I haven't tried it yet. Remove positive, hold it above post, if car dies then it's a bad Alternator.
Bad Idea, don't do it.......if you want a "poor mans" test for the charging system quick diagnosis,...
Try this, with the car running, take a screwdriver and touch the bearing, located in the CENTER of the REAR CASE, if you feel magnetic attraction, the alternator is working, however, if the battery is still not charging, chances are it's the voltage regulator, this is just a "quick" diagnosis test to generally locate the issue,...you should have a meter to understand exactly where and what is going on in the system
mike
Posted By: RapidRobert
Re: Is this a good Alternator test ... - 10/29/11 03:22 PM
What Dayclona said. Yes rarely a diode or maybe something else inside the alt is reducing it's output but k.i.s.s. that'll quickly confirm/deny the alt as the prob then let you move on to the reg/grounds etc. #1 in electrical is a good battery that's been PROPERLY load tested to confirm it's good EDIT and first it must be fully charged for a valid test as in slow charge overnight
Posted By: therocks
Re: Is this a good Alternator test ... - 10/29/11 04:46 PM
Easy just take it to any Big Brand parts store.They will test the whole system free.I like load testing the alt.That way you know how many amps it puts out under a load.Rocky
Posted By: Pool Fixer
Re: Is this a good Alternator test ... - 10/30/11 01:25 AM
Quote:
I did that quick and easy test once in high school. My car(barracuda) was running with the headlights on, I pulled the cable and the car started to die so I put it back on. That was dumb lol, it burned out every single light bulb in the car that was on other than the tach light(autometer). Evidently the regulator told the alternator to go full steam and when the battery was hooked back up it caused a voltage spike. The only lights that worked after this were the turn signals, brake lights, and high beams, the only lights not turned on at the time.
I spent a good chunk of change at the parts store for all the lights.
I recently canned the mopar charging system. I put a GM CS130 alternator on the car. Now with headlights, electric water pump, fuel pump, and fan it idles at 13.9 volts. Thats with a 5" crank pulley even.
I don't see the need to totally can the mopar charging system. Modify? YES... but you can easily run a 130 amp denso of an early 2000's chrysler product and retain the external regulator. Add a fat wire between alt and starter relay and it's good to go.
Posted By: DANA60
Re: Is this a good Alternator test ... - 10/30/11 01:54 PM
he bottom line is: What makes you think the charging system is bad? If your alt meter in the car shows a discharge then yes things need to be checked. If a volt meter is not showing more then 13.5-14.5, then things need to be checked. Yes, you could go to the GM style, but that's not ness. if things are checked and fixed. I, and I'm sure all Mopar owners, have had their issues with the stock charging systems for decades and they do work. Five items: Alternator, voltage regulator, wire conections (black from alt., VR field conections, bulkhead, alt. meter conection, redwire back out to battery) and battery. It's not complicated.
Posted By: Bad340fish
Re: Is this a good Alternator test ... - 10/30/11 05:10 PM
Quote:Quote:I have the diagram to hook that one up. is there a special year/make to ask for and will some spacers and fabbing a simple bracket mount it or does it need a custom bracket
I recently canned the mopar charging system. I put a GM CS130 alternator on the car.
I believe I asked for an alternator for a 91 buick century.
Mine is not stock under the hood at all and I am using a fabbed bracket that I bought. I have a small block with a mezziere electric water pump so the stock alternator mounting doesn't cut it.
Posted By: Bad340fish
Re: Is this a good Alternator test ... - 10/30/11 05:15 PM
Quote:Quote:
I did that quick and easy test once in high school. My car(barracuda) was running with the headlights on, I pulled the cable and the car started to die so I put it back on. That was dumb lol, it burned out every single light bulb in the car that was on other than the tach light(autometer). Evidently the regulator told the alternator to go full steam and when the battery was hooked back up it caused a voltage spike. The only lights that worked after this were the turn signals, brake lights, and high beams, the only lights not turned on at the time.
I spent a good chunk of change at the parts store for all the lights.
I recently canned the mopar charging system. I put a GM CS130 alternator on the car. Now with headlights, electric water pump, fuel pump, and fan it idles at 13.9 volts. Thats with a 5" crank pulley even.
I don't see the need to totally can the mopar charging system. Modify? YES... but you can easily run a 130 amp denso of an early 2000's chrysler product and retain the external regulator. Add a fat wire between alt and starter relay and it's good to go.
I agree that can be done and would work great.
I only use the factory wiring for the lights and wipers, everything else runs off of a relay panel I made(elec water pump, fuel pump, fan, MSD.) I mainly went with the GM alternator as it fit the only bracket available for a small block with a mezziere water pump.
Posted By: roe
Re: Is this a good Alternator test ... - 10/30/11 06:07 PM
Quote:
I read this somewhere awhile back but I haven't tried it yet. Remove positive, hold it above post, if car dies then it's a bad Alternator.
I've done it many times, but I think I removed the neg cable, with no ill effects