Problem: My bulbs all seem to blow out way before they should. Regulator adjusted.

[Loco_Hosa]

Howdy yall,

Problem: I seem to blow out light bulbs very quickly.

Theory 1: My regulator is nearing worn out on the alternator therefore the voltage has spikes and dips? (Not been noticed on the Gauge)

Theory 2: My Batteries are garbage, so the entire charging system is strained? (These batteries are 2+ years old, and they have not been the best taken care of)

Background: My truck seemed to being going through bulbs very quickly from the time I first purchased it. It sat for a long time while I re-did the brake system, but after sitting for about 20 months I have begun to drive it again. I ordered brand new 24 volt H4 bulbs, where on the second short trip both bulbs become blown out and deformed, I believe due to the regulator being out of adjustment. After adjusting it I put new H4s in and purchased some new dash bulbs, which only operated for about 6 total hours of drive use before one seems to have blown out.

The batteries measure 24 volts when not being charged, and 27-28 when the truck is running. The readings do seem to bounce around just a little.

Closing: Thanks so much for taking time from your busy day and reading this, I would love some help.

 

[Loco_Hosa]

Dog gone it, I didnt mean to post this under the Hot-Rodding forum. My bad yall.

 

[cranetruck]

Voltage readings appear close to normal...
Check and clean your battery connections and as long as the batteries are fully charged 2-3 years is far from an aging battery. Now, if they have been sitting at less than full charge, replace them.

 

[doghead]

Do you idle a lot?

Vibration will kill them.

The headlight mount rubber isolators get hard with age.

I know we've posted replacement choices.

Turning up your idle a little helps too. Watch your steering wheel and adjust untill it stops vibrating.

Be sure your grounds are clean.

 

[moving chicane]

Be sure your grounds are clean.

One of the first things I would check.

 

[MarcusOReallyus]

Theory 1: My regulator is nearing worn out on the alternator therefore the voltage has spikes and dips? (Not been noticed on the Gauge)

Possible, I suppose. You won't see that kind of thing on the gauge, though. It comes and goes too fast for the gauge to register it. You'd need a 'scope to see it.


It would sure stress your bulbs, though.

But before you go there, I'm with doghead. Check the grounds. Bad grounds do very strange things.

 

[steelandcanvas]

Follow the Big-Dogs advice, he is right on the money. I have put almost 6000 miles on my truck in the past 4 years, and have never had to replaced a lamp. My truck idle is set for about 800 RPMs, that takes a lot of the shake out.

 

[doghead]

One more thought, look over all of your positive cables. Look very closely for a short to ground. A large intermittent load could cause spikes that would blow bulbs.

Known bad spots are near the turbo, under the edge of the cab,and the hole in the frame near the battery box.

 

[Dblbeard]

I noticed you said 27-28 volts while running, do you mean at idle or with the rpm's higher? Also, are you running a stock generator or a newer 24v alternator? If the readings you are getting are at idle, have you idled the engine up and then checked the voltage?

 

[Loco_Hosa]

Wow everyone, thanks for the prompt replies!

Voltage readings appear close to normal...
Check and clean your battery connections and as long as the batteries are fully charged 2-3 years is far from an aging battery. Now, if they have been sitting at less than full charge, replace them.

The batteries sat for 12 months unloved and they didn’t look new when I purchased the truck, who knows how old they were or how they were treated. Then, they show signs of wear because of being overcharged before I adjusted the regulator. They do need to be replaced, I’m just trying to determine where on the priority list. Could this be the cause of my problem?

Checked the grounds, they are clean and good.

Do you idle a lot?

Vibration will kill them.

The headlight mount rubber isolators get hard with age.

I know we've posted replacement choices.

Turning up your idle a little helps too. Watch your steering wheel and adjust until it stops vibrating.

Be sure your grounds are clean.

You know, I have wondered if this could contribute, and I have felt it idled just a bit low due to the intense vibrations before. Thanks for the helpful input!

****, now that I think about it this could explain why it’s only the cab and front end lights that give me trouble, and NOT the tail/brake lights....

Possible, I suppose. You won't see that kind of thing on the gauge, though. It comes and goes too fast for the gauge to register it. You'd need a 'scope to see it.


It would sure stress your bulbs, though.

But before you go there, I'm with doghead. Check the grounds. Bad grounds do very strange things.

So it could be the regulator, but it would be hard to tell without some extra equipment?

One more thought, look over all of your positive cables. Look very closely for a short to ground. A large intermittent load could cause spikes that would blow bulbs.

Known bad spots are near the turbo, under the edge of the cab,and the hole in the frame near the battery box.

I will be checking all of these. Thanks!

I noticed you said 27-28 volts while running, do you mean at idle or with the rpm's higher? Also, are you running a stock generator or a newer 24v alternator? If the readings you are getting are at idle, have you idled the engine up and then checked the voltage?

I had the engine running about 1500 RPMs when I adjusted the alternator, and its the newer 60 amp alternator.

 

[Dblbeard]

As the guy said above, check for a ground. The best way to see how to do it is do a search on youtube, that way you can actually see a visual representation of
what is being explained.

Also, use the amp probe like the guy said above and take readings on the circuits, this will tell you where the main current draws are.

However, blowing bulbs like that points at a short to ground like the guy above also said. Sometimes a ground can be very hard to find. The easiest way to narrow it down is if you do
find that a circuit is shorted, start taking fuses out one at a time and you should see the ground go away when you take out the right fuse.
Then its just a matter of tracing that circuit down.

 

[doghead]

There is only one fuse on a deuce.

 

[197thhhc]

I still have to go back to the grounds and not just the battery cable ground. Did you take the grounds off and clean then retighten them? If not you should. Thats the only way to know for sure if the ground is good. Use the wiring diagram and make sure you hit all the grounds.

 

[cranetruck]

An alternator/generator will produce large voltage spikes if the connection to the battery is interrupted (=bad connections). It is know as a "load dump" when this occurs and the voltage can easily be in excess of 100 volts.

 

[Dblbeard]

cranetruck, Ive been working on cars for over 30 years and I've never heard that. I'm not saying it's not true, I just have never heard that. I work on robots, plc's, and all other types of controls, but I've always said that if a man can work on a car he can work on anything. They can be the most aggravating things to work on.

 

[AN/ARC186]

LH,

feel free to stop by on weekends, I'll help you go through the electrical, have the connectors and lugs and such on hand.

Dblbeard, had a dodge truck brought to me with a similar problem, due to a bad connection to the alternator it was pumping out over 75 volts. you can imagine the havoc that created.

 

[cranetruck]

cranetruck, Ive been working on cars for over 30 years and I've never heard that. I'm not saying it's not true, I just have never heard that. I work on robots, plc's, and all other types of controls, but I've always said that if a man can work on a car he can work on anything. They can be the most aggravating things to work on.

Google "load dump" and learn.
This is from one of my old General Glectric Metal Oxide Varistor manuals, it's dated 1976, so there is nothing new about it.
The regulator often fails due these transients, so never remove the connections to the batteries when the engine is running.

I don't think that light bulbs are particularly sensitive to this, but mention it anyhow.

Oh, yes, the reason for the connection to varistors is that the MOVs are very often used to absorb the transients, but not always included in the design.

 

[Diecorpse]

I had a similar problem. I had two new military batteries and less than a year one shorted out. Caused my alt regulator to short out and I blew six bulbs and melted the red plastic in the instrument panel. I learned from a mechanic why it is a common problem. The military batteries are glass lined instead of metal. This allows the battery to be charged many times when low. However overtime and vibration these glass cells will crack then they lose power or short out. Most batteries are made this way. The metal lined batteries are not prone to to die as much and turn to junk after two or three times running them down that low. However they are not acceptable to the vibrations so thats why they are used in industrial equipment like dozers and such. They have more cca as well. The mil alternator are fine but they have their fair share of problems and they are very expensive and not as easy to come by. I switched to an AC Remey 24v with 120 amps. It was about three fifty for a new one and most local retailers can order them. The catch is they are smaller so your original bracket that connects alt to block will have to be removed and a custom bracket will have to be made with new belts too. This set up allows easier alt adjusting and removal with one large bolt. I also went with napa dozer batteries that are 980 cca each! Much better set up than the origanal and she turna over very fast and starts very quick, even in - 10 f temps! But since then all my electrical problems perished. The whole set up only cost me$680 with labor and that is still cheaper than buying the military batts and alt. I hope your issue is an easy one to fix, but in the future if you replace those components, I hope I help you with a better educated decision.