Flickering headlights after swap

[Ramcharger90]

Yes I put a cam in, yes I know some times that's the price you pay. But its super annoying. Those headlight are flickering and the volt gauge jumps around but always in the normal operating ranger according to the ranger factory gauge. There has to be something that can be done. I can see at at idol this would happen but it shouldn't be happening going down the road.

 

[PetroleumJunkie412]

Led headlights?

In line capacitor?

Separate battery?

Voltage Regulator?

2.9 swap?

 

[Ramcharger90]

Led headlights?

In line capacitor?

Separate battery?

Voltage Regulator?

2.9 swap?

Regular headlamps!

No, and IDK how to do that!

Same battery the 4cyl was using

?‍

Im not a raging homosexual sooooo no 2.9l

 

[PetroleumJunkie412]

Regular headlamps!

No, and IDK how to do that!

Same battery the 4cyl was using

?‍

Im not a raging homosexual sooooo no 2.9l

SIR, YOU GO STRAIGHT TO HELL


You're in PA, eh?? Donut delivery time.


You're on your own list now, pumpkinfucker.











Insulted by my own kind... This Fiat merger is really taking its toll.

 

[RonD]

Your Alternator has a failing Field coil or Diode

The battery is only used to start the engine, its voltage is 12.3v to 12.8v
After engine starts the alternator takes over ALL voltage requirements, its minimum voltage is 13.5volts, so higher than battery voltage, which is why battery is not used at all when engine is running.

So your flickering lights and voltage gauge, with engine running, means the alternator voltage is fluctuating

An alternator uses 3 Field coils in its outside case to generate AC Voltage, each field's AC voltage is passed thru 2 Diodes to make it DC and usable for the Vehicles electric system
So I would guess one of the fields or a diode is failing causing voltage to jump around, at any RPM

You can test this by unhooking the alternator, unplug its 3 wire connector, that will turn it off
Start engine and see if head lights still flicker
If not then replace alternator, or rebuild it

If they still flicker then you have a loose connection in electrical system

You can only run the engine without the alternator for an hour or so, then battery will be drained and won't be able to restart engine

A more common sign of a completely failed field coil is dimming head lights at idle, no they are NOT suppose to do that, lol
Alternator can only make 2/3's of its rated power with a bad field coil so voltage drops too low at lower RPMs

 

[adsm08]

I've found a good test for a failing diode is to check for AC voltage at the battery with the engine running. About .01V per diode seems to be "normal", so up to .03V is OK, any more than that is excessive. In most cases by the time you have flickering lights you have close to half a volt coming out.

 

[Ramcharger90]

Your Alternator has a failing Field coil or Diode

The battery is only used to start the engine, its voltage is 12.3v to 12.8v
After engine starts the alternator takes over ALL voltage requirements, its minimum voltage is 13.5volts, so higher than battery voltage, which is why battery is not used at all when engine is running.

So your flickering lights and voltage gauge, with engine running, means the alternator voltage is fluctuating

An alternator uses 3 Field coils in its outside case to generate AC Voltage, each field's AC voltage is passed thru 2 Diodes to make it DC and usable for the Vehicles electric system
So I would guess one of the fields or a diode is failing causing voltage to jump around, at any RPM

You can test this by unhooking the alternator, unplug its 3 wire connector, that will turn it off
Start engine and see if head lights still flicker
If not then replace alternator, or rebuild it

If they still flicker then you have a loose connection in electrical system

You can only run the engine without the alternator for an hour or so, then battery will be drained and won't be able to restart engine

A more common sign of a completely failed field coil is dimming head lights at idle, no they are NOT suppose to do that, lol
Alternator can only make 2/3's of its rated power with a bad field coil so voltage drops too low at lower RPMs

Only problem its a 98 explorer alternator. In a 90. Using a mishmash of 92 mustang, 90 ranger, and 98 mountaineer wiring. Lol it was wired in using the 2 wires the explorer would use and I made a cable with a fuse going from the stud to the battery. So I wasn't sure if that was a factor.

 

[RonD]

No, that shouldn't cause an issue as long as you used a Mega-Fuse, and stud and battery connection are good

Just unplug the 2 wire connector, the Green wire on that connector is the ON/OFF switch for alternator
If its unplugged then alternator has no "startup voltage" so will stay OFF when you start the engine for the test

And +1 ^^^, for the AC Voltage test, when alternator is plugged in of course

 

[91stranger]

Sounds like a Johnny Cash song.

 

[RonD]

If you have a volt meter then I would also check voltage on the alternators yellow wire when its unplugged, it should show battery voltage, key off, and move wiring harness around while testing to make sure it doesn't have an intermittent issue

Yellow wire is used by the voltage regulator, inside alternator, to measure "pushback" in the system
When you turn on the headlights or Blower to high there is less pushback so regulator increases alternators output(amps) to keep voltage the same
When you turn these off then pushback goes up so regulator lowers the amps to keep voltage the same

If your yellow wire has a bad connection, intermittent, then regulator could be jumping amps up and down, although I don't think that would be described as a "flicker", but maybe
If the yellow wire is a problem you can wire it to the stud(B+) using an inline 15amp fuse

After you start the engine, battery is drained so alternator/regulator sees lower pushback from battery so you will see voltage above 14volts for a few minutes until battery gets recharged, then as pushback increases(battery is recharged) regulator will lower amps so voltage is under 14volts, 13.5v-13.8v is normal range after engine has been running a few minutes

 

[Ramcharger90]

Sounds like a Johnny Cash song.

That was the joke I made originally when I joined here.

 

[Ramcharger90]

If you have a volt meter then I would also check voltage on the alternators yellow wire when its unplugged, it should show battery voltage, key off, and move wiring harness around while testing to make sure it doesn't have an intermittent issue

Yellow wire is used by the voltage regulator, inside alternator, to measure "pushback" in the system
When you turn on the headlights or Blower to high there is less pushback so regulator increases alternators output(amps) to keep voltage the same
When you turn these off then pushback goes up so regulator lowers the amps to keep voltage the same

If your yellow wire has a bad connection, intermittent, then regulator could be jumping amps up and down, although I don't think that would be described as a "flicker", but maybe
If the yellow wire is a problem you can wire it to the stud(B+) using an inline 15amp fuse

After you start the engine, battery is drained so alternator/regulator sees lower pushback from battery so you will see voltage above 14volts for a few minutes until battery gets recharged, then as pushback increases(battery is recharged) regulator will lower amps so voltage is under 14volts, 13.5v-13.8v is normal range after engine has been running a few minutes

Ill check it out thanks