Head lamp valve voltage

[roy4matra]

Hello all,

I'm new on here so forgive me if this has been asked before but I did a search first and couldn't see anything that answers my query.

I'm a technician with 40 years experience, have a classic of my own, and help classic car owners in my spare time. It is my first time working on a Plus 2S/130 and the fault is that the head lamps won't come up when switched on. Now the reason is that the (3 terminal) relay in the valve is not operating. The positive and negative are O.K. but the third wire - the operating feed, is not giving enough power to activate the relay. But here is the interesting thing and the question I wish to ask:

The valve is marked as a 24 volt unit. Is this correct?

The head lamps have been operating until recently, so the fact that the operating feed has low voltage at the moment is obviously the main reason for the current fault and I have to trace where it is losing potential, but it can't be helped by the fact that this is a 24 volt unit on a 12 volt car. So I'm wondering if they were all fitted like this, or is this a mistake and a contributing factor as it's an incorrect voltage unit.

The second point is that if I give the feed a boost and it switches over then the spring brings the head lamps up, but not fully as if the spring is weak, with age maybe? It is not some vacuum holding them back as it is the same if I completely disconnect the vacuum. Is this a common fault, and is there an easy cure or simply a new spring required?

Thanks for any help you can give.

Roy

[c42]

Hi Roy

Fancy meeting you here, sorry I cannot help with this problem but the +2 headlights sure makes a Murena look straightforward! I am converting my +2 to use Mazda headlamp motors, hopefully they will not be so fickle.

Best regards
John Lockwood

[Jason1]

Hi Roy

Try posting a pic of the part as the systems are different for different year +2.

Do you have a copy of the workshop manual? There is lots of useful info in there.

Jason

[roy4matra]

Hi Roy

Try posting a pic of the part as the systems are different for different year +2.

Do you have a copy of the workshop manual? There is lots of useful info in there.

Jason

I will take a picture next when I see the car tomorrow or Monday.

There is a workshop manual but it only seems to cover the Elans S1 to S4. Certainly there are no circuit diagrams for a +2S 130/5 or any info. on the Pull down/Spring up headlamps.

Roy

[stugilmour]

Welcome Roy.

You mention 'spring'. Wondering if you are missing one spring? Lights should be solidly up when no vacuum present.

Mine is a Federal car, which had a bar between the two light pods, and one vacuum cylinder. However, this setup has two springs to move the pods to the up position if vacuum runs out. You ca see a diagram of both setups at rdent.com in the Plus 2 parts manual section. The light pod hardware is under body / exterior/ Headlights.

Sorry I can't help with the solenoid valve as my car used a manual valve in the light switch assembly. Like Jason mentioned there are several versions over different models.

I also converted to Toyota motors rather than replace the duff vacuum cylinder.

HTH

[roy4matra]

Welcome Roy.

You mention 'spring'. Wondering if you are missing one spring? Lights should be solidly up when no vacuum present.

I would agree, they should be firm when up, otherwise you would have them bobbing up and down over bumps. It may be this car has not been used at night for some time so the owner hasn't noticed, but they are definitely too soft.

Mine is a Federal car, which had a bar between the two light pods, and one vacuum cylinder. However, this setup has two springs to move the pods to the up position if vacuum runs out. You ca see a diagram of both setups at rdent.com in the Plus 2 parts manual section. The light pod hardware is under body / exterior/ Headlights.

Sorry I can't help with the solenoid valve as my car used a manual valve in the light switch assembly. Like Jason mentioned there are several versions over different models.

I also converted to Toyota motors rather than replace the duff vacuum cylinder.

HTH

Thanks for the rdent reference. That looks a very useful resource. That listing only shows the Federal cars as having the single vacuum servo and electrical relay/valve and a bar between the lights, but this UK car is similar, and I'm fairly sure I only saw one spring, so you may be right that one is missing - maybe broken at some point. I will certainly be inspecting again (with more knowledge about it) next visit. Thanks for your help.

Roy

[Jason1]

Some bedtime reading

http://gglotus.org/ggtech/elan-hdlamp/headlamp.htm

and

http://www.rdent.com/manuals/index.html

go to:

Elan +2
Body
exterior
pop-up HL

[bob_rich]

Hi Roy

I have posted a picture of the valve in my december 73 Elan +2S 130 (which started life as a /5) picture as with it striped down after cleaning up. There were no markings on it but after assembly with 12V applied it passed around 1.3A.

the system (on mine) used a single vacuum cylinder with both pods linked by a bar and with two return springs one much stronger than the other --this is apparently as it should be. The two springs certainly hold the lamps up OK and after a lot of fettling with the reservior position the system seem to work OK. Not fnshed the car yet but have test out using a hand vacuum pump and all seems 2 B fine

Hope this helps
Best of luck

Bob

[roy4matra]

Hi Roy

I have posted a picture of the valve in my december 73 Elan +2S 130 (which started life as a /5) picture as with it striped down after cleaning up. There were no markings on it but after assembly with 12V applied it passed around 1.3A.

That's interesting since this car is nothing like that at all. The valve almost looks like an industrial valve with integated relay. Is is one block with the ports at one end and the relay at the other, with three terminals sticking out on the side. Two of the terminals (the relay positive and negative) are female Lucar and the third operating terminal is a male Lucar blade.

Hope this helps
Best of luck

Bob

Thanks Bob. It certainly seems to indicate that this car has been modified at some stage and that the 24 volt rating is a consequence, and probably not correct.

Roy

[roy4matra]

Some bedtime reading

http://gglotus.org/ggtech/elan-hdlamp/headlamp.htm

As you might gather from my log-on name, I am familiar with Matra sports cars - I have a Murena which I've had from new in 1983 and the Bagheera was the model before it and they both used vacuum for the pop up lights. One difference was they used a double acting servo, so the lights are sucked up and sucked down. They have a manual pull cable in case things fail.

The Bagheera used a cross tube of the chassis as a vacuum reservoir, and just like it explains in that article, the end caps eventually leak as corrosion sets in. And in a similar way they are difficult to re-seal since they are not easy to get at.

The Murena however, uses an ABS plastic vacuum tank for a reservoir. Similarly many diesel cars a few years ago needed a vacuum reservoir for their servo brakes because with no throttle plate they did not create the vacuum like a petrol engine. (today's common rail diesels are different and very often have a throttle plate) So these diesels often had plastic vacuum reservoirs too.

The reason I mention this here is that if an Elan reservoir is leaking, rather than go to the trouble of trying to repair and seal the cross tube, the better way would be to fit one of these plastic reservoirs. They are small, light, and tough, and would easily fit in the spare space in the front of this Elan +2; not sure about the smaller Elan, but I think one might as I don't imagine it is much smaller. You would have a reliable vacuum reservoir that lasts. My Murena is 30 years old and still has no trouble with the reservoir.

Roy

[Jason1]

the better way would be to fit one of these plastic reservoirs.

I have seen this done and as you say they are easy to get hold of.

You will need to check that the front cross member is the problem. I had a leak on my +2 which turned out to be one leaking pod and a leaking dash switch (early car). After chasing leaks and driving in the dark with the pods going up and down I found it less frustrating to fit MX5 motors.

Jason

[GerardJPC]

Roy is working on my Plus 2, and has worked also on my Murena and Excel. I recommend Roy highly as an excellent classic car mechanic.

[GerardJPC]

Thanks for all help. The lamps now go up properly:-

[roy4matra]

Hi Roy

I have posted a picture of the valve in my december 73 Elan +2S 130 (which started life as a /5) picture as with it striped down after cleaning up. There were no markings on it but after assembly with 12V applied it passed around 1.3A.

To let other know how it was cured and (if I get this right) I am attaching a photo of the valve on this car (before I had done the repairs).

As I suspected the low voltage at the operating relay connection was due to wiring corrosion and poor terminal joints. I replaced the three terminals at the relay and repaired other joints which were going green (corrosion in copper wiring) and even though the valve is marked 24 volt, once I had a full 12 volts plus, the relay and valve operated.

As for the springs, there were two springs but they were not operating fully, as one was fouling and restricting the other. Once fitted properly, the combined spring pressure was enough to raise the lamps properly and hold them up against the stop.

Thanks again for all the help and guidance.

Roy