best electrical question EVER
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best electrical question EVER
1990 e 250 4.9 new alt new battery excellent wiring. while engine is running and nothing no lights or heater or any drain everything is great. turn things on engine runs like crap miss fires bucks and acts stupid. no AC ripple from alt. 14.4 stays constant. today i was replacing idler pully and started engine with no alternator belt to hear the difference in sound from bad pully bearing. this is when i found out that i could run any and all accessories without causing a misfire. voltage was 11.5ish of course belt back on and ran engine with accessories on and back to misfires and crap. there is a capacitor on the coil pack to reduce noise that i have not checked or replaced but that's it. crazy
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good question , the old one had an external voltage regulator that got damaged when i was changing the engine. the new one has internal and is a better alternator.
Mountain Pass
Joined: Jan 2014
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From: Madison Ohio
I would have to say you just proved that it is a problem with you alternator, or in the hook up? You say no ripple on output? How did you read this? What did you do with the old external voltage regulator and wiring? IS the new alternator a one wire? OR 3g upgrade? Or ?? If you have no issues without the alternator running and issues when its running I say it's in that factor someplace.
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I would have to say you just proved that it is a problem with you alternator, or in the hook up? You say no ripple on output? How did you read this? What did you do with the old external voltage regulator and wiring? IS the new alternator a one wire? OR 3g upgrade? Or ?? If you have no issues without the alternator running and issues when its running I say it's in that factor someplace.
Tuned
Joined: Oct 2020
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Sounds like something is going to ground that is causing your poor engine performance.
As you turn on each accessory is there a specific point where the engine runs bad? Did the bench test show the new alternator was good? Is everything plugged back in after the engine swap? Kind of a can of worms!
As you turn on each accessory is there a specific point where the engine runs bad? Did the bench test show the new alternator was good? Is everything plugged back in after the engine swap? Kind of a can of worms!
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update went back to alternator shop with alternator in hand .when they tried to test it they cloud not get the belt tight enough under load so now they are tearing it apart.
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Tuned
Joined: Oct 2020
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Too may times over the years I have installed a "new" starter or alternator only to find it did not work. Usually a remanufactured.
So recently did an alternator for a friend (PITA) and before I left the auto parts store (NAPA) I requested them to bench test it. Guy was a bit of a dick about it saying "why? It's brand new" so I told him because it's better to know before I install their "life time guarantee" than later... It bench tested fine and I said Thank You. Was in a Honda.
Never leave the store without bench testing the new one!
So recently did an alternator for a friend (PITA) and before I left the auto parts store (NAPA) I requested them to bench test it. Guy was a bit of a dick about it saying "why? It's brand new" so I told him because it's better to know before I install their "life time guarantee" than later... It bench tested fine and I said Thank You. Was in a Honda.
Never leave the store without bench testing the new one!
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