The alternator replacement thread, Fixed! Options

[VaccaRabite]

Waiting on the side of the road for a flatbed to take me home.

Engine ran great. Charging system not so much. Driving along. Lights started going dim. Car started bucking. Only 5 miles to home but it wasn’t going to make it, and no shoulders to pull over safe on the little farm roads. So I pulled into a spot I knew of and shut it down and parked it and now I wait.

McMark had said earlier he wasn’t sure about the charging system. But the alt light was not on and no issues before now.

So. What’s the alternator I need to buy?
Maybe a new VR as well?
I guess I should test the battery and make sure it’s okay too.

Zach

[FL000]

That sucks, I know the feeling. Same thing happened to me Friday but with a broken CV joint. Good that you are close to home and hopefully an easy fix.

[ClayPerrine]

Did you check the generator light bulb? The wrong one will cause the alternator to fail to charge.

[VaccaRabite]

Bruce Stone is the man and has an alternator for me. Hopefully that is the issue and not a crapped out relay board or faulty wiring.

Zach

[bobboinski]

Did you check the generator light bulb? The wrong one will cause the alternator to fail to charge.

Seriously? The more I know about these cars the more I love them!

[ClayPerrine]

Did you check the generator light bulb? The wrong one will cause the alternator to fail to charge.

Seriously? The more I know about these cars the more I love them!

Very serious. The generator light provides the circuit to the alternator field. If the alternator is not charging, the light comes on because of the voltage differental between the alternator and the rest of the electrical system. When the alternator is charging, both sides of the bulb are "hot" so the light goes off.


That's why you can't use an LED in the generator light socket.

[Mark Henry]

(IMG:style_emoticons/default/agree.gif)
The alternator idiot light was on when you turned the key before starting right?
The light excites the field, so no light before starting and the alternator won't work.
Your alternator light not coming on once the charging system failed tells me something was wrong with the idiot light wiring circuit. That will also need to be fixed.

The two idiot lights are very important, I won't start my engines without them working correctly first.

[VaccaRabite]

Yup. Red light was on when I turned the key and went off when the engine started.

The light never turned on while I was driving. Just noticed the lights started getting dim about 10 miles into a 20 mile drive.

After I turned the car off on the side of the road, the alt light did not light when I tried to start the car again when the tow truck showed up. But the battery was really drained by then.

Zach

[Unobtanium-inc]

I hate the site of a pretty Porsche being dragged, this was my car at my dentist's office, the last place I wanted to spend any extra time.

Hopefully your car is something easy.

[VaccaRabite]

I probably would have made it home if I had not needed to use the headlights. But, I would not have noticed the problem were it not for the headlights dimming and assumed something was wrong with the EFI when the car eventually started bucking.

Zach

[Mark Henry]

Yup. Red light was on when I turned the key and went off when the engine started.

The light never turned on while I was driving. Just noticed the lights started getting dim about 10 miles into a 20 mile drive.

After I turned the car off on the side of the road, the alt light did not light when I tried to start the car again when the tow truck showed up. But the battery was really drained by then.

Zach

That is odd, as a preventative I'd still go through your grounds and connections at the combo gauge. Also make sure your battery posts, battery and trans ground straps, etc., are all clean and have good continuity.
Bad battery and ground connections can make your electrical system do wierd shite.

[bobboinski]

Yup. Red light was on when I turned the key and went off when the engine started.

The light never turned on while I was driving. Just noticed the lights started getting dim about 10 miles into a 20 mile drive.

After I turned the car off on the side of the road, the alt light did not light when I tried to start the car again when the tow truck showed up. But the battery was really drained by then.

Zach

That is odd, as a preventative I'd still go through your grounds and connections at the combo gauge. Also make sure your battery posts, battery and trans ground straps, etc., are all clean and have good continuity.
Bad battery and ground connections can make your electrical system do wierd shite.

I had a bad ground on my Tacoma and the headlights would turn themselves on (dimly) and the warning buzzer would sound at about half volume. This would happen randomly. Guy I worked with said to check the grounds and he was right. Negative clamp on the battery was severely corroded so I replaced it and all has been fine for over a year now. Learned my lesson.

[r_towle]

get an amp gauge.

Bummer, but you are so close man....glad you stuck with it.

rich

[Spoke]

I wouldn't put in a new alternator until you know what is wrong with the charging system. Like Mark said, check all grounds and battery connections.

Charge the battery, remove the VR, short DF to D+ at the VR connector. This will put the alternator in maximum charge condition. Start the car and measure the battery voltage. If it is more than 15V, then the alternator is ok. Don't do this test too long as it applies maximum stress on the alternator and battery.

If you don't see 15V or so, the VR may be suspect.


I know the feeling of a Porsche riding on a flatbed. This ride from Pittsburgh to Allentown a couple of weeks ago cost me a cool $1000.

[Dave_Darling]

I had a VR that came unplugged while I was driving. No warning light, and no charging either. The light did stay off after I shut the engine off and turned the key back on again, though.

--DD

[bdstone914]

Bruce Stone is the man and has an alternator for me. Hopefully that is the issue and not a crapped out relay board or faulty wiring.

Zach

I also have rebuild tested relay boards should that be the problem. Done by 914Sixer, Mark Heard.

[Amphicar770]

I wouldn't put in a new alternator until you know what is wrong with the charging system. Like Mark said, check all grounds and battery connections.

Charge the battery, remove the VR, short DF to D+ at the VR connector. This will put the alternator in maximum charge condition. Start the car and measure the battery voltage. If it is more than 15V, then the alternator is ok. Don't do this test too long as it applies maximum stress on the alternator and battery.

If you don't see 15V or so, the VR may be suspect.


I know the feeling of a Porsche riding on a flatbed. This ride from Pittsburgh to Allentown a couple of weeks ago cost me a cool $1000.

Ouch! If you drive older cars, AAA Platinum is a must have. My Jaguar got a free flatbed ride from Virginia to North of Philly about a year ago.

[Unobtanium-inc]

[/quote]

Ouch! If you drive older cars, AAA Platinum is a must have. My Jaguar got a free flatbed ride from Virginia to North of Philly about a year ago.
[/quote]

Yes, AAA is a must if you're driving an old car. Plus you save at hotels and stuff.

[dr914@autoatlanta.com]

yup you ran out of juice, would check the belt tightness and then the voltage regulator, a new Bosch alternator is the final solution if the other two fail to 'rectify"

Waiting on the side of the road for a flatbed to take me home.

Engine ran great. Charging system not so much. Driving along. Lights started going dim. Car started bucking. Only 5 miles to home but it wasn’t going to make it, and no shoulders to pull over safe on the little farm roads. So I pulled into a spot I knew of and shut it down and parked it and now I wait.

McMark had said earlier he wasn’t sure about the charging system. But the alt light was not on and no issues before now.

So. What’s the alternator I need to buy?
Maybe a new VR as well?
I guess I should test the battery and make sure it’s okay too.

Zach

[bdstone914]

I wouldn't put in a new alternator until you know what is wrong with the charging system. Like Mark said, check all grounds and battery connections.

Charge the battery, remove the VR, short DF to D+ at the VR connector. This will put the alternator in maximum charge condition. Start the car and measure the battery voltage. If it is more than 15V, then the alternator is ok. Don't do this test too long as it applies maximum stress on the alternator and battery.

If you don't see 15V or so, the VR may be suspect.


I know the feeling of a Porsche riding on a flatbed. This ride from Pittsburgh to Allentown a couple of weeks ago cost me a cool $1000.

AAA Extended plan cost about $160 a years and well worth it. You get two tows per year up to 200 miles each . Did that after a 25 mile tow cost $125 with towing "insurance". But I see that is is closer to 300 miles from Pittsburgh to Allentown.