Too much voltage to headlights?

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HTMLmopars

HTMLmopars

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I installed @crackedback 's headlight relay kit something like a month and a half ago. Worked great, no problems. I had put new headlights on the car just before I installed the new wiring, they were the midlevel parts store ones, sylvania, like 15 bucks each. Went to drive across the state and it turns out both headlights are cooked, brights and low beams on both headlights, not working at all. Bought new ones at the gas station and it all worked again. But about 3 hours down the road, I lose the driver's side low beam. High beam still works and passenger side is still 100%. I looked and I'm getting 14.5-14.8v at the headlight connector when the engine is running and at some rpm. Is it overcharging and killing the headlights, or are the emergency gas station headlights just junk? (they were like 20 bucks each).
Note: one of the boxes from the gas station headlights looked like it had been sitting on the shelf since before I was born, now I'm not that old, but 20 years is pretty old for a headlight.
 
Those voltage levels should not kill the headlights. Is that voltage while plugged into the headlight and on?
 
That's what I thought.
I took the headlight retainer loose, used a zip tie to keep it from falling and connected the lead directly to the exposed part of the terminal where the harness connects. Car on, and then gave it some rpm.
 
That voltage is barely too high. If the battery never gets above that it is very close. Voltage with engine WARM (VR is temp / voltage sensitve) 13.8--14.2

Are they firmly/ properly mounted, or do they shake and vibrate?
 
The passenger side might not be as well held in as it could be, theres some damage to that fender, but i hadn't had any problems with headlights until now, over 20,000 miles with zero issue with the headlights themselves. Driver's side is pretty well mounted now, but having installed them in the gas station parking lot at like 8pm with a leatherman tool, i don't know for sure if that one was tight or not. Passenger side still works, driver is the one that lost.

And i put a gauge on the alt just to see and once she gets up to temp, it seems to hold steady for alt output right at 14, maybe occasionally 13.9, 14.1 but never outside that range.
 
Lord Sparky said:
Did you ever figure this out?
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No, and I actually had both headlights pop on the way home from work a month or two ago. Just turned them on and bam, off. No brights, no low beams, nothing. Had to use markers for my 35 mile commute, swapped another set of parts store special headlights in and am running those now, but I just avoid running the car at night so I don't have to worry about them going out.
 
I cannot imagine what is going on, unless you have some voltage surge for a short period You could run 15.5--16 and it likely would not shorten bulb life by very much

Bumpy/ washboard road?
SURE?? the lights are rigidly mounted? They must NOT rattle and bounce
Any indication of surge? Weird "lights brighten" some time?
I'd be hookin up a voltmeter to monitor supply voltage for awhile, night and day, to see if it's doing something weird

What do you have for an alternator/ regulator? I mean, is it stock pre-70 stuff, or have you swapped "something else" in there or what?

Maybe you just got some "old stock."
 
I'm running relays i my daily driver and I use low beams about 5 hours a week.
I think my voltage is about what his is.
Somewhere between 14 and 15 volts.
What I've noticed is GE Nighthawks don't seem to last as long. Its like that line in Blade Runner.
The candle that burns brightest burns quickest.



..
 
68Valiant225 said:
The passenger side might not be as well held in as it could be, theres some damage to that fender, but i hadn't had any problems with headlights until now, over 20,000 miles with zero issue with the headlights themselves. Driver's side is pretty well mounted now, but having installed them in the gas station parking lot at like 8pm with a leatherman tool, i don't know for sure if that one was tight or not. Passenger side still works, driver is the one that lost.

And i put a gauge on the alt just to see and once she gets up to temp, it seems to hold steady for alt output right at 14, maybe occasionally 13.9, 14.1 but never outside that range.
Click to expand...
Just think about how this works. You can't have a system voltage higher than the alternator output unless you have a lazy charging system and a freshly charged battery from a battery charger. Your 14-14.6 is normal output.
 
I know one thing..........."near the end" of incandescent bulbs in the big "energy save crisis" those chinese crap didn't last anywhere nearly as long as the old ones.....and you could not find quality ones. I'm speaking of home lamps. I STILL HAVE two 130V/ heavy duty clear bulbs "from the old days" must be 20 years old I used to use in the garage that work.
 
I'm going to make a big hip shot here and recommend a 0.01uf capacitor across the make contacts of the relay. Cheap ceramic capacitors at any voltage above 20 will work. Let me know what happens.
 
billccm said:
I'm going to make a big hip shot here and recommend a 0.01uf capacitor across the make contacts of the relay. Cheap ceramic capacitors at any voltage above 20 will work. Let me know what happens.
Click to expand...

Not relevant. Lighting is not an inductive load and none of the relays in a modern vehicle have caps across the contacts. Besides, how can switching burn up lights?
 
You might have a weak ground, not an open ground, that is creating a higher resistance on the circuit down steam from the lamps. This could be putting strain on the elements causing premature failure.
On an ac circuit such as in your house a weak neutral will cause the same thing.
 
moparmarks said:
The lamps should be able to handle 15 volts but maybe some of the China crap won't?
Click to expand...

Can you point us in the direction of non Chinkesium crap? Does anybody make it anymore?
 
67Dart273 said:
I cannot imagine what is going on, unless you have some voltage surge for a short period You could run 15.5--16 and it likely would not shorten bulb life by very much

Bumpy/ washboard road?
SURE?? the lights are rigidly mounted? They must NOT rattle and bounce
Any indication of surge? Weird "lights brighten" some time?
I'd be hookin up a voltmeter to monitor supply voltage for awhile, night and day, to see if it's doing something weird

What do you have for an alternator/ regulator? I mean, is it stock pre-70 stuff, or have you swapped "something else" in there or what?

Maybe you just got some "old stock."
Click to expand...

For charging system I've got a squareback alt with the mopar voltage reg. It's been a minute since I looked at that wiring, but I remember taking my time and making sure was correct.

I'm thinking my budget headlights are the problem. But I don't wanna put more expensive lights in it just so they can pop like the cheap ones
 
What do you mean, "Mopar regulator?" That is what I'm trying to find out.........what regulator exactly, do you have? 69/ earlier stocker, or the auto parts replacement? Or the "race" regulator? Or did you convert to the 70/ later "flat" electronic?

There is some chance that the thing might be spiking at some point, which is why I suggested monitoring it--and I mean "as you drive"
 
67Dart273 said:
What do you mean, "Mopar regulator?" That is what I'm trying to find out.........what regulator exactly, do you have? 69/ earlier stocker, or the auto parts replacement? Or the "race" regulator? Or did you convert to the 70/ later "flat" electronic?

There is some chance that the thing might be spiking at some point, which is why I suggested monitoring it--and I mean "as you drive"
Click to expand...

Sorry, its the 70s solid state regulator. I meant that it's the legit Mopar part, not parts store junk.
Mopar Performance 77R06286 Mopar Performance Voltage Regulators | Summit Racing

I'll have to get the ol girl out this weekend and monitor voltage while I'm driving. One weird thing is that the lights popped right when I turned them on, the car was idling and I had just started it. Didn't really seem like they're wearing out, just that they saw too much power or something.
 
That is exactly why I suggest monitoring system voltage. Not necessarily with lights on, but for a period of time just as you drive. Maybe the charging system is doing "something."

One of first things I'd do is check or maybe just "improve" grounding. Add a starter cable "eyelet to eyelet" between body and engine. On a v8 the same holes in the front of the pass side head are at the rear of the drivers side head. Get about a 1 foot starter cable and attach to head, and to firewall, the master cyl. studs are one place

Make CERTAIN voltage regulator is grounded. Remove, clean around firewall holes and rear of VR flange, and remount using star lock washers.
 
I know it's not super accurate, but, have you noticed the AMP gauge jump or hold at far right position? This would indicate voltage (amperage) spikes that maybe blowing those cheap headlights?

Just a thought...
 
Voltage and amperage are not the same. Actually they are inversely proportional.
Might take two minuets and check your headlight grounds or just keep chasing the rabbit.
 
A ground jumper between the motor and body is always a good idea. I use a braided ground strap like the factory did on later cars. On small block cars to goes from the coil mount to the wiper motor.
 
65Val said:
I know it's not super accurate, but, have you noticed the AMP gauge jump or hold at far right position? This would indicate voltage (amperage) spikes that maybe blowing those cheap headlights?

Just a thought...
Click to expand...

This actually IS a good idea --if you still have a working ammeter-- Jumping around indicates some sudden (unwanted) change, such as a loose connection or even stuck/ gummy/ worn out brushes
 
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