1999 Windstar lights bright and dim

[ozarksman]

Hi,
I noticed the other evening that my 1999 Windstar lights, headlights and interior, sort of pulsed from normal to dim, back and forth. A few miles back, 2,000 or so I put a new rebuilt alternator on, $189.00 worth; do you suppose that the alternator is bad already or could it be something else? Any suggestions would be greatlyl appriciated!

[randkell]

Originally Posted by ozarksman

Hi,
I noticed the other evening that my 1999 Windstar lights, headlights and interior, sort of pulsed from normal to dim, back and forth. A few miles back, 2,000 or so I put a new rebuilt alternator on, $189.00 worth; do you suppose that the alternator is bad already or could it be something else? Any suggestions would be greatlyl appriciated!

My 1999 ford windstar is doing the same, I have recently replaced the alternator and checked the battery connections. Have you resolved your problem

[LeSabre97mint]

Originally Posted by randkell

My 1999 ford windstar is doing the same, I have recently replaced the alternator and checked the battery connections. Have you resolved your problem

Hello

Is the brightness relitive to your engine speed? How about the load you have on your electrical system? It could be a bad ground....somewhere...

Six years old is old enough to have corroded wiring or corroded ground locations.



Regards

Dan

[wiswind]

I had a Motorcraft rebuilt alternator (about that same price) burn out in less than a month.
By burn out....I mean the side of the case melted....molten alluminum.... I believe that the windings went out. The alluminum heatsink on the regulator was fine....but the case over the alternator windings was melted.
So....yes, a "new" alternator can fail.

There is a fue for the alternator in the engine compartement Power Distribution box (also contains relays). It is "T" and is 15 amp....it is a little mini fuse....This is on my '96.

The Black with orange strip wire that connects to the alternator stud connects to fusable links "A" and "B" and from there to the positive battery terminal.



The other thing that I would do is consider the battery.....anything over 5 years is old.
I bought a battery from Autozone, 1000 Cranking amps, 850 Cold Cranking Amps (CCA)....and the price was resonable.

Sometimes the 2 items (alternator and battery) fail together. A bad battery can place a load onto the alternator.

[12Ounce]

You may want to hook up a elect pigtail into the cigar lighter. (Radio Shack can sell you some plug hardware.) To this you hook up a voltmeter, inside the cabin, and watch for voltage fluctuations. The cigar lighter is fuse protected, but other than that is "hot at all times" ... right off the battery plus buss.

The headlights, on the other hand, are fed thru "switched power relays".

I kinda expect you will find your problem in the alternator ... but it's not a slam-dunk.

[randkell]

Originally Posted by LeSabre97mint

Hello

Is the brightness relitive to your engine speed? How about the load you have on your electrical system? It could be a bad ground....somewhere...

Six years old is old enough to have corroded wiring or corroded ground locations.



Regards

Dan

It is not reletive to the engine speed, driving at a constant speed the inside lights, headlights and heater fan fluctuate at the same time. I am going to hook up my voltmeter with a full load and watch it for volt loss. I may have a new alternator that is going bad.

[randkell]

Originally Posted by randkell

It is not reletive to the engine speed, driving at a constant speed the inside lights, headlights and heater fan fluctuate at the same time. I am going to hook up my voltmeter with a full load and watch it for volt loss. I may have a new alternator that is going bad.

I Checked with the volt meter, sitting idle it was drawing 14 volts, as I turned on the lights, radio and heater it dropped to 12 volts. When I accelerated it went up to 14 volts and as I took my foot off the gas it dropped back down to 12 volts again.

[wiswind]

Sounds LOW.

You can have the alternator tested at most auto parts stores. Might be the way to go.

[randkell]

Originally Posted by wiswind

Sounds LOW.

You can have the alternator tested at most auto parts stores. Might be the way to go.

The alternator checked out good but they replaced it anyway. The new alternator resolved the problem. It appears it was not charging at low RPM. Thanks for the help!!