White Lightnin'

Going to my local PCA meeting last week & temps were mild, so I had windows open & tunes goin'.

I got a couple of pops & crackles from radio & lights flickered at same time -then both my low beams went out. I had all my other lights though. So I flipped on the high beams & continued on my way. Leaving the meeting... same thing, high beams only.

Before work the next day, I checked low beam fuses & swapped the XXIII/XXIV Combination Headlamp relay with a known working spare. No change. I even swapped the okay low beam fuses (#38 & 39) with new ones. No change.

That night, getting ready to leave work -same pop, crackle, flicker & I lost my high beams (H5's). But I also lost my dash lights. Fog/Driving lights worked, so I used them to get home. Turn signals, marker lights, brake lights, tag lights, & dash warning lights all work. Fog switch lights up when activated, Hazard switch lights up when activated.

Being advised from another member of possible ignition switch issues I performed the following:

1. Jiggled key in ignition while running & lights supposed to be on... no change.
2. Tested & confirmed power at input of fuse #1 (Central Locking).
3. Replaced with new X-Bus relay (IV/4)... no change.

Another night, sitting still with engine & parking lights on, I had the interior light over the rearview on and it increased in brightness, only to settle back to normal.

During daylight today, at different times I had the tach needle jump and the alternator charge needle jump. On each occurence, slight crackle in radio and no changes otherwise to drivability.

Each occurence I had the radio on. It is a removable-face aftermarket head unit that was professionally installed... possibly related?

I had another possible idea... I live in a rural area -what wires under the hood could have been chewed on by mice (or other creatures) that could lead to the symptoms I am having? My car doesn't sit still for days at a time, so I don't think anything is being chewed on... it's my daily driver.

So, my focus is any of the following:

A. Headlight switch
B. Potentiometer (dimmer)
C. Ignition switch

I believe these all to be original units... any thoughts or other things to test?

Mrmerlin

I would start at the radio and include the ashtray and clock wires,
also consider what was the last thing you fixed?

Also inspect the wire harnesses that run under the headlamps,
they can shear at the clamps that anchor the wire bundle ,
make sure there is flex in the cable when the light is up

HaydenM1974

When you say pops and crackles from the radio I assume you mean the speakers....from past experience on other cars it sounds like a bad ground. Not sure if your problem is similar to mine but I have some play in my turn signal switch which also switches between low and high beams and it causes them to switch back and forth with the slightest vibration....

White Lightnin'

Nothing recently fixed... and yes, the crackle was heard via the speakers.

What is especially confusing is how it is going in stages... but fuses are fine.

1. Low beams gone
2. High beams and dash backing lights gone
3. Weird bright then normal interior lights
4. Jumping tach needle & jumping (pegged) alternator needle -then returning to normal

Yet:
Dash warning lights work
Parking lights work
Brake lights work
Turn signals work (and cancel as normal)
Gear indicator lights work
Interior lights work
Stereo lights work (not wired to work with dimmer)
All gauges function as normal (except for the recent jumping)
Fog lights work
Auxiliary high beams work (driving lights)
Fog/Hazard/Defrost switches light up when activated
"!" light and cancel button light up
Central door locking button lights up
Clock works
Seat belt chime works

But, since I am losing function in different things in stages -I can assume these will also cease.

More ideas?

The Forgotten On

Check all of your grounds. Inspect the ground strap for corrosion as that can cause all sorts of weird issues.

Check your positive battery wire that goes to the starter. That is something commonly overlooked and can corrode really badly.

HaydenM1974

At this point are the bulbs still good. Halogen bulbs tend to be more sensitive to voltage fluctuations and they may be burnt out. With that in mind maybe a voltage regulator issue?

SMTCapeCod

Daytime only car now, or did you get it sorted?

White Lightnin'

Dang SMT, that avatar pic is sad...

Yeah, I forgot to update my own thread... no excuse for that!

It was the voltage regulator (within the alternator) that was causing the over-charging spikes.

The results of this part failing:

1. Low beam filaments (both) popped... then,
2. High beam filaments (both) popped and the fuse for the dash lights popped... then,
3. Daytime only for a while... then,
4. Overcharging caused battery to 'boil' and noxious gasses filling cabin (first thought it was MAF melting).

Replaced:

1. Voltage regulator (PITA with no lift!)
2. Battery
3. Headlight switch (for good measure)
4. Headlight bulbs (cheapos at first to verify fix)
5. Assorted fuses

All good now...

Thanks Hayden... you were dead on!

Mrmerlin

FWIW since you have just experienced a regulator over charge failure,
it would be wise to pay attention to your volt meter,
as if its charging more than normal it will also be seen on this gauge.
NOTE any non normal reading you see on the gauge should trigger you to put a volt meter on the hot post ,
see what the charge rate is at 1500 RPM, it should be from 13.5 to 14.2v if its over 14.6 then the regulator is over charging, replace it with a factory Bosch part or PRhone.
if its under 13.4v then you have a blown diode .

White Lightnin'

That would be good to see under differing operating conditions.... lights, wipers, defroster, etc. -differing demands on the system while driving.

There probably exists an aftermarket gauge that will show this that could be installed in the interior somewhere... I will have to look into it.

Thanks!

danglerb

I have a couple of the three or four LED battery diagnostic testers that sell between $5 and $10 and plug into the cigarette lighter. Only time I didn't get an accurate diagnosis was with a blown cigarette lighter fuse. If something seems wrong with one of these, check at the jump post to verify.