Headlight Bulbs blowing, charging at 16volts!

[andy 0]

I recently replaced my headlight bulbs as one had blown, I put in the Phillips +80% ones recommended on here. However they have only been in a couple of weeks and they have both blown the dipped element, it went on both bulbs at the same time, just after startup. I replaced the bulbs and one of the new ones has blown the same element within 200 miles. Anyone else had this, googling it seems to suggest voltage regulator issues (overcharging). How easy are they to get at/ any idea how expensive/does this seem likely?

[Philuk 0]

bit of a long shot but you dont slam the bonnet from a height do you. i bust headlight bulbs in my old car because i slammed it too hard! just a thought really! lol

[v8rumbler 0]

You need to get a voltmeter on your system . S/b showing 12+ volts without the engine running and around 14+ volts when it is running. Any more than that and you have a problem.

 

Sent from iPhone 4 using Tapatalk

[andy 0]

bit of a long shot but you dont slam the bonnet from a height do you. i bust headlight bulbs in my old car because i slammed it too hard! just a thought really! lol

lol no, although my koni suspension is on the firm side! I don't think it's that though as the old bulbs lasted 4 or 5 years.

 

You need to get a voltmeter on your system . S/b showing 12+ volts without the engine running and around 14+ volts when it is running. Any more than that and you have a problem.

Yes I figured that was the next step, not sure my analogue meter is accurate enough, might have to borrow a digi one.

[jamiehamy 0]

I've got the same issue, although it only started after I fitted an upgraded loom with OEM connectors. I've had to unplug it as i've been through 3 sets of bulbs, including the same Philips ones.

 

Problem is, the lights are shocking without the loom! argh!

[andy 0]

I reckon you may have the same problem as me then, I reckon the uprated loom has highlighted an excessive voltage. You may well have had excessive voltage output from the alternator/voltage regulator previously but not seen it at the bulbs due to the 5m of cable and associated volt-drop. Now you're running the bulbs straight off the battery effectively you are getting the full (over) voltage?

[andy 0]

I have measured the charging voltage at 16 volts. I assume its new regulator time! Anyone know how much needs to come off to do this on a VR? It looks like the whole fornt panel will need to be removed :-(

[davidwort 0]

I have measured the charging voltage at 16 volts. I assume its new regulator time! Anyone know how much needs to come off to do this on a VR? It looks like the whole fornt panel will need to be removed :-(

 

use the search Luke

 

viewtopic.php?f=1&t=86274&hilit=vr6+alternator

[jamiehamy 0]

I have measured the charging voltage at 16 volts. I assume its new regulator time! Anyone know how much needs to come off to do this on a VR? It looks like the whole fornt panel will need to be removed :-(

 

 

Gosh! I've not got a multi meter handy and completely forgot to get one today. Sounds like this will be my problem too. Sorry if this seems a silly question, but where did you measure the voltage? Across the battery when running, or from the alternator wire to earth?

I'll need to search replacing the regulator...hmm...At least i like fixing so will get done at the same time as I paint the shocks etc... :) Busy weekend ahead!

[andy 0]

use the search Luke

 

viewtopic.php?f=1&t=86274&hilit=vr6+alternator

 

Cheers :) , hadn't quite got to that search yet, was trying to find Regulator part numbers!

[andy 0]

Sorry if this seems a silly question, but where did you measure the voltage? Across the battery when running, or from the alternator wire to earth?

 

Just across the battery, 12V without engine running, 16V ish with it running, should be more like 14V.

2 min job.

[v8rumbler 0]

You are lucky to have only blown a couple of bulbs---- could have been a lot worse!!

 

Sent from iPhone 4 using Tapatalk

[andy 0]

Indeed, she's been running really well too. I'm surprised the ECU is so resilient (he says, touching wood!).

[jamiehamy 0]

Funny you mention ECU's, my car is very temperamental, sometime fast and good economy, sometimes slow, sometimes poor economy.

 

One thing i notice is that if i run the engine fans (via the bypass switch I've fitted), they run at idle, but revving to 1k, they pick up a fair amount of speed. Obv the rev will produce more voltage, but it's a pretty big jump.

 

Figuring if this happens with the fas, it must be happening to other components like you say V8. Will update how I get on once i've checked it tho...

[jamiehamy 0]

hmmm... checked voltage tonight, max 14.2v. Bummer. Will try a couple more times, in case it's intermittent. Back to the drawing board for me :(

[andy 0]

hmmm... checked voltage tonight, max 14.2v. Bummer. Will try a couple more times, in case it's intermittent. Back to the drawing board for me :(

Looking at how difficult the alternator is to get out, you may have the preferable option! Maybe running a voltage guage into the car temporarily would help to see if its intermittent.

[jamiehamy 0]

Yeah, alternator is a pain, but only because you have to strip the front, which is not a big deal really, but nonetheless, a lot of work for what will only be a small amount of work.

 

I usually save up tasks and do them in a oner. Do you have anything else you need to do?!

 

Good shout about temporary in-car meter to check. Will also rewire the loom and see if that makes a difference.

 

Will keep posted!

[andy 0]

I usually save up tasks and do them in a oner. Do you have anything else you need to do?!

Yes, bottom end swap/head refurb/chain replacement!..... Not urgently, just desirable sometime in the future. On a more serious note, yes I need to rewire my oil temp switch as the wire has broken, redo my headlight relay wiring (5 years of weather has taken its toll), blue temp sensor must need replacement by now and a coolant swap (easier without front on) , so yes a few other jobs to do while its out. Mines not been off, certainly in the 6 years/60k miles I've owned it, possibly never (150k/16 years), I'll get the plusgas/wd40 ready!

[andy 0]

As an update, got my alternator out today, don't need to take the front of the car off. I removed off-side headlight, air filter housing (BMC in my case but shouldn't make any difference.), belt tensioner and front grill. I then took the nuts/bolts off the front and rear engine mounting and jacked the engine a couple of inches. You can then remove the 2 bolts holding the alternator on. Afer levering the very seized alternator out (it had grown in!) you can get to the electrical connections and remove them. Without rusty/seized bits/bolts shouldn't take more than 1/2 hour. Mine is in a right state, rusty, casing split, regulator goosed. So I have decided to buy a new Bosch one from GSF for £100. Giving my BMC a proper clean whilst its out too!

[Kevin Bacon 5]

Yep, that /\ is the standard way to remove it! It's definitely a front end off job if you have a 120A alt though as it's frickin massive!

[andy 0]

Mine was a 70A luckily, loads of space :D

[Kevin Bacon 5]

Yeah I remember my 70A coming out easily using your method. But putting the 120A in.....hmmm....down with the tools, put the kettle on and mentally prepare yourself for a much bigger job!

[jamiehamy 0]

Any thoughts on why mines keep blowing Kev? I've checked several times and voltages are al normal. Everything on the car operates as it should and really at a bit of a loss as to what to look for :( Lights worked great with the loom connected, but just kept blowing the bulbs. :(

[andy 0]

How many bulbs have you blown, is it always the same element, both sides of the car?

[jamiehamy 0]

Blown three, two on passengers side, one on drivers.

 

Interestingly the first bulb as a cheap one from a spare bulb kit and it actually melted the glass into a boil like protrusion!