Headlamp question.

[Mad4slalom]

Hi all, out for a little run in the 72 this eve. Was running on side lights then it got to dusk so raised the head lamps.
Stopped in a fuel station for some E5, I put the headlamp switch back to position one ( side lights) and fuelled up. I noticed the headlamps stayed up whilst engine was off and side lights were still on. Headlamps go down as normal when headlamp switch is pushed all the way in to “off”
Is this normal or another vac leak quirk ? TiA

 

[James Vette]

Not sure about 72 but on my 71 they go down if on position one for sidelights.

 

[Mad4slalom]

Not sure about 72 but on my 71 they go down if on position one for sidelights.
I was pretty sure mine did usually, i just thought if the over ride switch under the column was in the down position , that would do it, the lights went off when switched to side lights but i wonder if the over ride switch prevented them from closing although isnt the over ride supposed to stop them closing even when switched off

 

[Roscobbc]

Sure you haven't activated the override switch under the dash?

 

[Mad4slalom]

Sure you haven't activated the override switch under the dash?

that is what I was just wondering but wouldnt that stop them from closing even when the lights are switched off completely ? I will go out and have a play tomorrow

 

[Mad4slalom]

that is what I was just wondering but wouldnt that stop them from closing even when the lights are switched off completely ? I will go out and have a play tomorrow

Thanks Rosscobb,
Both over ride switches are closed, ie up

 

[johng]

Was the engine running when you switched the headlamps to the off position?

 

[Emc]

The valve in the headlight switch only closes the vacuum on the main lights, not on the side lights
They did not go down because maybe there was not enough vacuum in the tank to do so

 

[Mad4slalom]

Was the engine running when you switched the headlamps to the off position? Hi johng, I had just stopped for fuel and to be honest I cant be sure if the motor was running or not when I switched them off. Would it make a difference if it was/was’nt ?

 

[Mad4slalom]

The valve in the headlight switch only closes the vacuum on the main lights, not on the side lights
They did not go down because maybe there was not enough vacuum in the tank to do so

thanks Gavin, I thought I had read that the vacuum tank holds enough for one or two open/close operations even with motor off, I may be imagining that tho I did once think I heard air escaping when I operated the headlamp switch, cant remember if it was when i was switching on or off tho.

 

[Emc]

thanks Gavin, I thought I had read that the vacuum tank holds enough for one or two open/close operations even with motor off, I may be imagining that tho I did once think I heard air escaping when I operated the headlamp switch, cant remember if it was when i was switching on or off tho.

Yes that's the point of it, but 50 years later, we'll who knows

 

[Mad4slalom]

Yes that's the point of it, but 50 years later, we'll who knows

hmm I think the general consensus is that not only are they 50 years old but also they are a bit hit and miss and a bit quirky in that its a bit of a lottery what they will do at any time . I suppose I should think myself lucky that they do mostly at least open and close when requested.

 

[johng]

Most likely you have a small vacuum leak (or 2), or your non return valve isn't working, so that as Gavin said "They did not go down because maybe there was not enough vacuum in the tank to do so".
On the other hand if you had turned off the engine, then switched the lights to position 1 (and they stayed up) and then turned the lights off (and they went down), I would say you have a problem with the light switch. Don't think this is very likely though.

 

[Mad4slalom]

Most likely you have a small vacuum leak (or 2), or your non return valve isn't working, so that as Gavin said "They did not go down because maybe there was not enough vacuum in the tank to do so".
On the other hand if you had turned off the engine, then switched the lights to position 1 (and they stayed up) and then turned the lights off (and they went down), I would say you have a problem with the light switch. Don't think this is very likely though.

thanks jg, I will do a run through of different scenarios and see what does what when I actually have a new hlamp switch in stock . Easy job? I have a mitie vac pump too so i can do some more testing. I checked the filter was clear and the chrome (non return valve ?) next to it and it held pressure . A friend said it can help to fit jubilee or similar clips to all vac hose connections to help eliminate small leaks ?

 

[CaptainK]

There is a position 1 and 2 on the headlight switch? On my 68 its "pull the lights switch rod thingy" to get the lights on (dipped lights) and headlamp covers up. Then a switch on the floor you press with your foot to get the main beam lights on.

 

[Mad4slalom]

There is a position 1 and 2 on the headlight switch? On my 68 its "pull the lights switch rod thingy" to get the lights on (dipped lights) and headlamp covers up. Then a switch on the floor you press with your foot to get the main beam lights on.

72 the same
Got to get mine out when the rain clears and see exactly what mine does and what affects what

 

[CaptainK]

72 the same
Got to get mine out when the rain clears and see exactly what mine does and what affects what

I genuinely didn't know how to run mine with just sidelights, and thought the headlight knob just turned all the lights on when pulled (and assumed it didn't have "just sidelights" as it was an old car). Did a Google and I see now there is a position 1 and 2, and also seems if you rotate the knob it alters the brightness of the lights in the dashboard... and maybe even turns the interior lights on when turned up to max. I'll have to try that next time I'm out in it. Learn something new every day.

 

[James Vette]

Just don't leave the interior lights on by accident when parked!

 

[Mad4slalom]

I genuinely didn't know how to run mine with just sidelights, and thought the headlight knob just turned all the lights on when pulled (and assumed it didn't have "just sidelights" as it was an old car). Did a Google and I see now there is a position 1 and 2, and also seems if you rotate the knob it alters the brightness of the lights in the dashboard... and maybe even turns the interior lights on when turned up to max. I'll have to try that next time I'm out in it. Learn something new every day.

love cruising around early evening with side or as they say in the states, “running” lights on

 

[teamzr1]

Also, a FYI that if having a C5 and newer

To prevent the parking/running lights being on and draining battery
Is with key off, pull up on the parking brake, doing so tells the BCM not to turn them on
Even then if waiting for the ole lady in the store burning your money, and you stay in the car, so you do not puke in seeing what she bought,
you can have radio on in ACC mode and those lights off helps voltage drain

Also, good to do when if using a OBD scanner and want to see some things with engine off or flashing a tune into the PCM or TCM