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MG MGA - Generator Test
|Guy's is there an easy test to determine if the generator is functioning or not? I not sure if I am running on my battery. I do not want to get to far from home until I confirm. Thanks!|
I assume that you do not have a voltmeter?
Is the ignition light on when the engine is running?
In the dark do the headlights get brighter when you go from idle to higher RPM?
|Yes Mick, I do have a volt meter and the Ignition light is on. My lights do not dim at all but I have a full charge on new batteries. What kind of readings should I be getting at the posts on the generator?|
|Your reading at the battery posts should be higher (about 14 volts or a bit less?) when the engine is running above idle, as compared to when the engine is off (about 12 volts or a bit more).|
That's an easy test, you can short the wires to the generator to test its output, but there's no regulation, so don't rev very high.
Here's a fun site that covers a lot of stuff like you may need now or later:
|Here's another link:|
|Since you have a voltmeter, here is a good step by step procedure for diagnosing the charging system. http://www.vintagemg.com/ArticlePDFs/Tech103.pdf|
|An easy test for the generator is to start the car and disconnect the battery. If the generator is working, it will be able to run the car, although you may have to give it a little gas to keep it running.|
I had an old Ford that I was able to drive to the auto parts store without a battery to get a new one.(the old battery had an internal short, so I disconnected it)
|For those with an alternator conversions, do not run the engine with the battery disconnected. You will blow an alternator diode.|
This is not a problem with generators, which will happily run without a battery connected.
|Thanks for your help guy's! Another question:|
Should the ignition light alway stay on? Or does it go out after the engine starts? How about if the batery is fully charged and not being charged by the generator, would the light be off?
|The light may flicker or come on at very low idle speeds. At normal engine speeds the light should stay off, irregardless of the state of charge of the battery. If it comes on at normal engine speeds, there is a problem with the generator or regulator.|
|Just something to try: whack your regulator (control box) with a screwdriver handle or something that won't break anything. Maybe it will unstick the points and make the light go out. After a long hiatus, I started my car and the light didn't go out. Hit the regulator, and it has been charging since. Kinda makes you feel like ol' Fonzie on Happy Days, hitting the jukebox in the right place to play a song.|
|Well, The light went out all right. For Good. when I first started it three days ago it appeared to work fine with the light coming on with the turn of the key. Noew I get nothing. I did Jeff's test of removing the battery cable while running and the engine died. Guess I will be ripping another part off again! Seems like for every three parts I put together, I have to go back and remove one to Re-Fix!. Here I was hoping "Lord Lucas" was going to go easy on me! Fat Chance :)|
This thread was discussed between 15/07/2007 and 17/07/2007
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