Alternator

[crouse]

I think my alternator failed. I went to start my Marauder and it turned over a little slower that usual. The volt gauge is down to around 10 volts with the engine idling. When I give it a little gas, the volt gauge doesn't move. When I turn the lights on, the gauge drops to about 8 volts, so I know the gauge is working. Anything else I should consider or check before I go by a new alternator?

[Invective]

I think my alternator failed. I went to start my Marauder and it turned over a little slower that usual. The volt gauge is down to around 10 volts with the engine idling. When I give it a little gas, the volt gauge doesn't move. When I turn the lights on, the gauge drops to about 8 volts, so I know the gauge is working. Anything else I should consider or check before I go by a new alternator?

First, make darn sure your battery and connections are good before you fire the parts cannon...

https://i.imgur.com/PTzV8y0l.png

[crouse]

Thanks. I check that tomorrow.

[rkk]

Is your battery light illuminated in the dash?

If yes, probably need an alternator, if no, then as Invective said, battery and / or connections.

[RubberCtyRauder]

check it with hand held voltmeter at battery with car running and off..dont totally trust the stock volt gauge

[crouse]

All of the connections to the battery are tight. With the engine off, my volt meter reads 11.6 volts. When I start the engine, my volt meter shows 11.2 volts. And the battery light is not in when the engine is running.

[crouse]

Any suggestion other than a Motorcraft alternator?

[fastblackmerc]

I like DB Electrical.

https://www.dbelectrical.com/search-results/#??Make=MERCURY&Vtype=AUTO%20AND%20LIGHT%20TRU CK&Model=MARAUDER&Year=2004&Enginetype=4.6L(281)%20V8

Just make sure it's a 4G alternator.

[RubberCtyRauder]

Have any starter, alternator rebuilders around?

[Invective]

All of the connections to the battery are tight. With the engine off, my volt meter reads 11.6 volts. When I start the engine, my volt meter shows 11.2 volts. And the battery light is not in when the engine is running.

Pull the battery out of the car (disconnect negative first), completely clean it, fully charge it using a standard charger then finish up with a smart charger. Why? A standard charger and the car's alternator will charge the battery to 80% capacity. The smart charger will push it to 100% capacity. Never use a smart charger to charge a dead battery as this isn't what they are designed for. I find it much easier to check the cable connections once the battery is out of the car. If the smart charger successfully fully charged the battery, take a proper battery load tester (at least 1000CCA) and check the battery. If it passes, then move on from there. Reconnect the battery, positive first, start Marauder and check battery voltage with no load. Do it right the first time - once and done....

[crouse]

Thank you for the assistance, however, the battery is about one year old. It's a Motorcraft battery. I'm fairly sure it's the alternator. I'll probably order one from DB Electrical as suggested by FastBlackMerc. And what is a 4G alternator?

[Invective]

Thank you for the assistance, however, the battery is about one year old. It's a Motorcraft battery. I'm fairly sure it's the alternator. I'll probably order one from DB Electrical as suggested by FastBlackMerc. And what is a 4G alternator?

It may very well be the alternator but you haven't verified anything yet. Why fire the 'parts cannon' without knowing for sure...

[Peace2Peep]

DB 220 amp alternator for the win! I love mine!!!

[crouse]

I did remove the positive and negative terminals from the battery. Everything looked good and there is no corrosion on the terminals. I reconnected the battery and started the engine. My hand held volt meter showed about 11 amps at the battery, so the alternator is not charging the battery. The car is almost 18 years old with 123,000 miles and the Motorcraft battery is 14 months old, so that's why I'm assuming it's the alternator.

[crouse]

Just an update. I ordered an alternator from DB Electrical on Monday. Thanks fastblackmerc for the referral. It arrived today. I just installed it and it working great. 14.5 volts while the engine idles.

[Phrog_gunner]

Just an update. I ordered an alternator from DB Electrical on Monday. Thanks fastblackmerc for the referral. It arrived today. I just installed it and it working great. 14.5 volts while the engine idles.

Did the high amp alternator require a new voltage regulator wiring harness or anything, or was it plug and play?

[fastblackmerc]

Did the high amp alternator require a new voltage regulator wiring harness or anything, or was it plug and play?

Plug-n-Play. Internal regulator.

I'd suggest a big 3 upgrade.... to anyone.

[dmjarosz]

I did the "big three" up when I moved the battery to the trunk and was shocked how much a difference it made. I even replaced the wire from the starter to the battery with 4ga and it actually cranks faster.

[Phrog_gunner]

Plug-n-Play. Internal regulator.

I'd suggest a big 3 upgrade.... to anyone.

Thanks Jim. I'm no electrologist, but if it wasn't an internal regulator then wouldn't it be a moot point about the regulator harness when changing the alternator?

My issue is actually more intermittent than crocuses. After years of sitting I've had the MM out idling in this ridiculous heat for hours on end and I think the AC draw is just too much for an old alternator. I know the stock volt meter is unreliable but when it drops to 10.5 or 11V I tend to get cautious. The box store test said charging system tested ok, but my voltmeter disagrees.

[fastblackmerc]

I don't follow about the regulator harness. The regulator is internal ie. inside the alternator.

Your alternator should be putting out around 14volth even at idle. The stock voltmeter is a as reliable as an aftermarket one or a good meter.

You could have bad connections at any of the grounds and positive points. One thing to check is the condition of the cables. sometimes there is corrosion inside the cables where you can't see it. Cables can be tested with an Ohm meter.