On this FD the odometer/mileage light, any light thats on inside or outside, with the car running has this pulsin like to it. Where it gets dimmer and brighter, almost with the idle of the engine. Any ideas????

Ever experience, not every....lol

 

Does it stop after it warms up?

Our humvees in Iraq did that, just how they ran, never happend to any of my Fd's, maybe your battery/alternators going.

 

I did a ton of stuff on the car starting in Feb. New Magnacore 10.5mm wires, but I've used them on other FD's and thats whats on mines and no problems.

I did have to lengthen a shielded wire on the main engine harness and I used a short pc. of reg. wire, however I've done that before too and never had an issue like this.

PFC shows good battery voltage at all times too. Guess I could swap out alternators and see what happens since its an easy check.

 

Ill say alternator/battery, bcause when you are going faster if it pulses faster its because the belt is spinning the alt giving power to the battery. Check your battery with a Voltmeter and make sure its at the right number, then start the car up and see if the alternator is charging it to its correct level. Without running it should be I think 12.4......or12.7, when running it should be in the upper 13's and lower 14's which means the alternators doing its job and supplying engery go the battery.

If those numbers are off someone plz correct me, but im pretty sure they are close.

 

Car has over 12v when not running and is always in 14-15's when running.

At first I thougt it may be an instrument cluster ground or something. Thing is the headlights, everything does it. Never gets low power, just pulses....

I wonder if his aftermarket ignition amplifier is doin this. Its right next to the battery. I cant see this being the problem though.

I got a feeling its the shielded wire on the engine harness I lengthened w/a non shielded one. I figured that would maybe just cause noise in stereo speakers, but maybe I was wrong.

I'm gonna eliminate what I can and the engine still run and see what happens?

 

If it fluctuate between dim and bright then it can be your alternator, you can get good voltage out of a bad alternator, gotta test it at Autozone or with a battery tester that can put a load on it.

If it pulses then you might have noise in your circuit.

 

When engine is started up PFC reads 12.0volts steady, no up or down until the voltage regulator kicks in. Then the voltage goes up and the pulsin starts.

Gonna swap out alternators and see what happens.

 

maybe check your ground wires as well!! a good ground can make the world of a difference

 

I had this same situation last year. Every light (including the odometer) would pulse at every rpm. The alternator has a voltage regulator on the back (where your clip plugs in). I replaced this item and all of the pulsing went away. I did find that it was cheaper to get a reman alternator than it was to just buy the voltage regulator. The reman was about $160 and the lowest price I could find for voltage regulator was just over $200.

 

Good news. Swaped out the alternator with one of the extras I got and wala...no more pulsin.

Thanks to those who tried to help. =_)

 

I told you from the get go it was your alternator.

Mazdaspeeddan strikes again, glad its fixed!

 

Yeah man, you were right on.

Thanks for the reply

 

Just got to this thread. It is the voltage regulator without a doubt.

 

unfortunately the regulators in remans are still used, and partially why remans are so unreliable.