Headlamps not switching off - help required!

[jimblob]

Thanks for that I'll give everything a good greasing when I get back of holiday.

[Chillidoggy]

What Derek says sounds perfectly logical to me Jimi, I'd start with the easy stuff. But if I have any other views on the subject when I get the new module, I'll post them up.

 

Might be worth having a look inside the pod lift module to see if there's any obvious signs of overheating on the circuit board.

[Chillidoggy]

Just don't you go thinking I'm an expert, because I'm far from it!

[Chillidoggy]

Ooooh, matron! There's more chance of me winning the lottery than fault-finding this little piece of gadgetry!

 

The guts of the failed pod delay module:-

[Jacques]

Without knowing the circuitry, I'd say first look for the obvious like all the soldering. One or more can go bad from heat/Cold and vibrations. And the two Black capacitors (or whatever they are called in English) can loose their value and begin to "lift" their top. Like a small buldge and after that they turn a little brownish. Cheap and easy fix, if that's the case.

At least they are known to give up after som 5-10 years, depending on spec., and could very likely be the first component in that circuitry to get unstable or give up completely.

 

Most smd's are pretty stable, even to rather extreme heating, so that is where I would look last.

The function of the coil could also be affected, if for example the lacquer on the copper is too thin some places, and in time melts through or by vibration. Should be easy enough to test.

 

The soldering to the relay connectors are obvious Places to look for a bad connection too, if for example it's been taken out and refitted a number of times, as just a small wiggleing can break the solderings on the socket connectors.

 

The IC could well be a little timer circuit, and should be easy enough to find (online), but I'm guessing here.

 

Just my two pence,

Jacques.

[Chillidoggy]

I might be a pedantic old sod, but I don't think I'll be delving into the workings of the module for the sake of a few quid! Might be different if they were unavailable, however.

[jimblob]

I ended up pulling the headlamp motor and found there were a bunch of little ball bearings all over the place inside the motor, ordered a reconditioned one to replace it as I have no clue on how to sort this myself.

[mdw]

You can buy rebuild kits from sjs or I think there is somewhere in the us that makes metal gears and rollers for them

[redshift]

Its a very common fault with PCB mounted relays in modules like this. I would guess that if you re-soldered the connections to the relay and the connector pins all will be resolved. Vibration coupled with the unsupported weight of the relay results in open circuits.

The fuel pump relay on the TVR is exactly the same, think I had bought 3 or 4 before stripping one apart and finding the real problem!

[sanj]

I ended up pulling the headlamp motor and found there were a bunch of little ball bearings all over the place inside the motor, ordered a reconditioned one to replace it as I have no clue on how to sort this myself.

How-to pictorial: http://home.earthlink.net/~turboesprit/headlight/index.html

Parts from http://rodneydickman.com/catalog/index.php?cPath=50

[jimblob]

You can buy rebuild kits from sjs or I think there is somewhere in the us that makes metal gears and rollers for them

On inspection the problem with mine is that a metal washer has snapped releasing small ball bearings into the motor itself, the plastic things that come with the rebuild kit are fine. I have ordered a reconditioned one from the guy who makes the metal gears.

[sanj]

Ah, I misunderstood, then. Cheers!

[sailorbob]

Whilst doing some unrelated tinkering I found that the headlamp wiring diagram in Section ML of the Service Notes is wrong for the A100M6048F main / dip beam & indicator switch. This is what it should look like. Hopefully it'll anyone fault finding in the future.

[Escape]

Well spotted Derek! I had to take a long and hard look to figure out what was wrong, but in the manual all three dots on the right side are connected (56 to 30), so the blue wire for the lights would always be powered via the purple feed...

Filip

[sailorbob]

I realised after I posted the picture I could have just shown this!

[eeyoreish]

So I realise I'm resurrecting an old thread here but it's the closest/most relevant I could find to my issue...

Fettling my Esprit (the 1990) for MOT after a while standing in the garage and I seem to have a headlamp pod problem. On the first few tests, both headlamp pods raised and lowered fine for dipped beam and headlamp flash. Then I remembered that I needed to clean some debris out of the bowls, so I did that and now the RH pod always lifts but mostly doesn't go down again ☹️

To clean the pods I removed the pod delay module K and also the dim/dip lift relay G (because I couldn't remember which one stopped the pods lowering when the lights go off). Pod arms also disconnected to reach under them and clear debris.

After I replaced everything I have this problem.

With the pod arm disconnected and the actuating arm off the motor removed (leaving just the spindle) the motor seems to run fine both ways as it should. However, when I connect the actuator and arm it will work in the up direction until the arm hits the up stop, then mostly doesn't go down again. I say mostly because once or twice it's worked but then refuses again. If I manually wind down the pod (easy, with no resistance) I get the same again on the next attempt.

I've removed the motor and checked the gears, re-greased etc and it's all moving freely with no obvious problems.

Possibly related (or not?) the dim/dip lift relay G is warm and I can feel it switching as soon as it's plugged in, almost like it's constantly energised. Having delay module K plugged in or not makes no difference to that.

I've also noticed that regardless of whether dim/dip lift relay G is plugged in or not my pods lift and lower (LH) and the lights come on so what on earth does relay G actually do??

Any help appreciated here as I really wanted to get the car through it's MOT this week.

Emergency plan B would be to present it for MOT with the pods permanently up, which presumably I can do by just removing the delay module K and manually winding both pods up to the stops?

 

[Escape]

Your plan B should work to pass MOT I think, don't see a reason why the pods need to lower.

As I understand it, the dim/dip relay has the dipped beam on at 10%(ish) when the sidelights are turned on. And  it also raises the pods of course. So in normal operation you wont notice a difference, as you're rarely running with just the sidelights on (actually, I do on occasion run just the sidelights, mostly to have the rear lights on when there is reduced visibility but no real need for the headlights).

As for the real problem, could it be the linkage that is binding? As the motor is spinning as it should without load and the gears have been checked. Maybe something got disturbed when you disconnected the linkage to clear the bowls?

Filip

[eeyoreish]

Thanks Filip.

Further investigation today revealed the following; what is supposed to be (by its position in the fusebox) the dim/dip relay is actually the aux power relay, which is why it was energising with ignition off but the key still in. One mystery solved. Clearly a PO has rearranged the relay holders at some point... All of which means it's at least unconnected to my pod problem.

It seemed that resistance or weakness of the RH motor might be the issue (because of the way it stops by detecting a resistance in the arm as it reaches the stop) so I investigated that further.

Firstly, I'd read on another forum that a lack of rubber pad on the stop tab can result in increased tension in the motor when it comes to a 'hard' stop, making it difficult for it to reverse off again. My rubber stop was mostly disintegrated so I fabricated a temporary one from a piece of hose. That improved things but every so often the motor still wouldn't lower the pod.

I removed and stripped the motor again, this time stripping out the electrical side too, not just the gear end. What I found was that some of the grease from the gears had found its way onto the motor brushes, no doubt affecting the contact and certainly blackening the contact surface a little. I cleaned and degreased everything, reassembled and re-adjusted the motor end float then refitted.

Now it seems to be fine.

So it looks like the combination of hard stopping against a metal stop added to a slight weakness in the motor was enough for the motor not to activate for the return journey. Probably operating it repeatedly helped to free things up, which is why I started to get a few more successes later yesterday.