Altinator

[vktorana]

Hey how do I know if the altinator is hooked up and charging the battery? It's all hooked up but I wanna be certain it's workin before we head off!

[vk.jonno]

If the ignition warning lamp stays on after the engine has been started and run at approx 1000rpm carry out the followingtl test and precautions;
1. Stop the engine, do not open cuircit any parts of the charging circuit whist engine is running.

2. Check cindition and adjustment of fan belt

3. Clean battery terminals, tighten all electrical connections, check the wiring for shorts to earth and/or bridged cuircuts and make sure battery is fully charged.

4. Start engine and allow to run until normal operating temp is reached

5. Stop engine and disconnect neg terminal.

6. Remove nut and washer from alternator output terminal and disconnect alternator output lead

7. Connect one lead of a 60-0-60 ammeter to the alternator output terminal and the other lead of the ammiter to the lead removed from output terminal.

8. Reconnect battery negative terminal and connect a 0-20 voltmeter across the terminals.

9. Switch on all lamps and allow them to burn for approx 5min to reduce the charge of the battery and apply a load to the cuircuit.

10. Start engine and gradually increase the engine speed to approx 2500rpm the reading on the ammiter should be approx 75% of the rated output of the altinator.
((11) switch off all lamps and run engine at 1500-2000rpm until the indicated charge is below 10amps. The volt meter should Now read between 12.5-14.7 volts.)

-gregories service manual #222 page 165-166

Hope it helps I just typed it out of a book.
And I'm using my phone so my hands hurt

[VR38]

Do you have a volt meter, just connect it up to the battery with the motor off,
a good battery around 12V then start it up should jump to 13V plus,
if the volts rise the alternator is working, if the volts stay the same and start to drop as the motor is running then the alt/reg is doing nothing.

[ari666]

LMAO!!! talk about overcomplicate things.

1. start engin
2. disconnect earth lead

is the engine still running?

no= alternator is NOT working
yes= alternator IS working


if the engine continues to run with the earth lead DC, and to check if the alternator is working well, turn on all your electricals, i.e. heater, lights hazards, foot on the brake, radio, cig lighter. all that stuff MAY cause your engine to die, if it does, reconnect the earth lead, start her up again, and this time turn all that stuff on while holding the revs at around 1800rpm (which is roughly the point where the alternator will 'turn on')

if its working the engine should continue to run with all the electrics on.

[vk.jonno]

Well maybe u should re-write the gregories manual then so I don't feel like a fool

[vktorana]

Lol ari is like a walkin talkin manual! Appreciate it dude!

[delcowizzid]

its the easiest way to kill an alternator if its not allready just use a multimeter on the battery terminals and check voltage

[ari666]

its the easiest way to kill an alternator

lol, how so?

[VR38]

You will overload the electrical system by disconnecting the earth while the motor is running, you should NEVER disconnect the earth while the motor is running, especially with an ECU, the charging system is meant to have a load on it, that load is the battery, if there is no battery where do you think the system will find earth to charge?

[VR38]

its the easiest way to kill an alternator if its not allready just use a multimeter on the battery terminals and check voltage

Hmm yeah would love to hear where this one come from lol.

[ari666]

???? the alternator doesnt just create +V

you disconnect the battery and it will find earth from the alternator...

the battery does absolutely F'k all for the running of your car. at the best of times a battery fully charged MAY go a little over 12V, but when your car is running it should be up around the 14.5V mark. the battery is only there to look pretty and let you start her up in the morning. after that the alternator does everything.

disconnecting the battery while it is running is no worse that taking a jumper lead off after jump starting your car with a flat battery.

[delcowizzid]

it burns out the diodes in alternators but thats the easy part to fix LOL

never let anyone dissconnect your battery with car running
The moment he disconnects either lead from your battery, it's entirely possible he caused thousands of dollars in damage. Here's why...

Your battery does more than just yield electricity. It also shorts AC, spikes and transients to ground. Removing the battery from the circuit allows those spikes and transients to travel around, endangering every semiconductor circuit in your car. The ECU, the speed sensitive steering, the memory seat adjustments, the cruise control, and even the car's stereo.

Even if your computers and stereo remain intact, in a great many cases removing the battery burns out the diodes in the alternator, necessitating a new alternator. If disconnecting the battery interferes with the voltage regulator's control voltage input, it's even possible for the alternator to put out hundreds of volts, frying everything.

Even the initial premise was wrong. If you disconnect the battery and the car conks out, you don't know if it conked out due to insufficient alternator current, or whether the resulting transients caused your ECU (the car's computer, which controls fuel mixture, timing, and much more) to spit out bad data, shutting down the car.

Nobody should EVER run your engine without a battery.

And yet when you tell them not to, they'll roll their eyes. "I'm a professional. I do this every day. It's fine!" They'll sound so authoritative. So commanding. So intimidating. But they're wrong.

The problem, of course, is that disconnecting the battery doesn't always damage something. It does it only sometimes. Less experienced jump start professionals and automotive technicians figure if they got away with it a few times, it must be OK

[ari666]

well VKtorana there you have your two opinions:
1. disconnecting the battery will burn everything in your car and wont tell you if the alternator is not working
2. disconnecting the battery will tell you if your alternator is working

i was gonna argue, but comments like "in a great many cases removing the battery burns out the diodes in the alternator" has just flabbergasted me. and decided its not worth the effort.