Alternator???

[Go Mifuni]

The other night (last Thursday on my way to the 99 to be exact :D) I was travelling down the highway and thought I noticed my headlights dimming. It was barely perceptible, and I thought I might be halucinating. I looked down at my volt meter and it was reading 12v. Not good! I pulled off the highway to check it, as I happened to have my multimeter with me, and as I came to a stop at the lights, everything got bright and it came back up to 14v. I decided to continue on my merry way, as beer was a higher priority than being stranded, and it was fine the rest of the night. This has happened to me two other times during the almost five years I've owned her; sometimes while stopped, this time while travelling at highway speeds.
Has this happened to anyone else? :confused:

[Raudermaster]

Do you have a tune? Did you go WOT?

[Bobmiddle]

Yea it has happened to me and still happens every once in a while even after a 200 amp upgrade about 6 mo. ago. maybe 2 or 3 times in the last 6 mo. I have no idea what it is. when I upgraded to new alt. I ran extra 4 gauge power and ground with fuses. The only thing I can think of in my case is I still have OEM battery that will need replacing b4 summer

[ctrlraven]

Yea it has happened to me and still happens every once in a while even after a 200 amp upgrade about 6 mo. ago. maybe 2 or 3 times in the last 6 mo. I have no idea what it is. when I upgraded to new alt. I ran extra 4 gauge power and ground with fuses. The only thing I can think of in my case is I still have OEM battery that will need replacing b4 summer

I was thinking about upgrading to a 200 amp alternator. Where did you get yours from?

[Go Mifuni]

Do you have a tune? Did you go WOT?

No tune as of yet. While on the highway, I matted it and got no response on the gage. It was weird. As I came to a stop, like right before I stopped, it came back up. Last time it happened, I was coming to a stop and it dropped.

[RF Overlord]

I was thinking about upgrading to a 200 amp alternator.
Be careful about that upgrade. I read somewhere (Police Fleet Manager magazine perhaps) that many high-amperage alternators will actually put out LESS current at idle and at very low speed than a smaller unit. That's one of the reasons CVPIs have the idle speed raised in the factory tune. Cop cars have a larger alternator to accomodate all the lights, radios, and computers that get installed, so unless you're planning on a mondo sound system that draws mega-amps, a larger alternator doesn't really buy you anything.

[jdando]

...Has this happened to anyone else? :confused:

Yes it has happened to me. Your alternator might being going bad. :depress:

When my alternator went out the voltmeter would "flicker" between 12-14 volts. With the lights/blower dimming/slowing down. The amount of time at the low voltage increased over a period of 1 week then the battery light started lighting up.

I replaced the alternator, fixing the problem and lightening my wallet by $370.

[Bobmiddle]

Where did you get yours from? A place called lincoln auto electric do a google search you should be able to find them. Just make sure they send you the right one they sent me the wrong one the first time. It was a very good deal also. And I do get a little dimming of the lights at idle So I would recomend a tune to bump up the idle a little. I am getting my tune next mo so i will not have that issue.

[Marauderjack]

DO NOT TRUST YOUR OEM VOLT METER!!!!:shake:

I have a ScanGauge II and the two ONLY agree at 14 Volts......Mine went to 12 Volts once so I bought a new alternator......got the exact same results with the new alternator!!:argue:

You need to remove the alternator and get a "Stress Test" done at an auto electric shop to really see if it's OK!!:D

My $.02!!:cool4:

Marauderjack:burnout:

[cougar9150]

Do you happen to know the output at idle. I have always used PA Performance alternators but they can be pretty expensive. The 200A unit for the Marauder is $439 not sure of the output at idle. The 130A unit put out 80A at stock and cost $299. They always have a higher output than stock at idle and come with a new clutch pulley. The 200A I put on my Cougar had 100A at idle. Never had a problem even with the bass thumping at a stop light. 1000W system with no cap. That included a electric fan setup from a 95 Mustang, tranny cooler/oil cooler in 1 w/a fan, and the high output mod done to the headlights.