Headlight Motor Copper Strip repair

[peteyg]

Hi all,

Any advice on removing, flattening and refitting the copper strip inside the headlight motor? I've never removed and replaced the 'rivet?' that holds the strip down. What's it actually called and what's the tool required to refit? ? The copper strip is too far bent to make contact and I can't straighten it in situ.

Cheers,

Pete

 

[snowrx]

You may be able to take a mild little coil spring and glue it under the switch compartment lid to hold down a damaged switch strip.

[Andyww]

Typical crap piece of Lucas design which carries current through rivets going into plastic. So the connection goes bad and gets warm, melts the plastic which makes the connection worse.

I think it is just about possible to bend those strips with thin nosed pliers in situ so they contact again. I cleaned everything up with wire brush then soldered the tags to the rivets on the 2 end connection and soldered tag to strip on the middle one.

[peteyg]

This one's beyond bending in situ...

[snowrx]

Well, in that photo it seems to be held open by the cam pin from below.  I followed the lead of a PO and added a closing spring. Photo I posted earlier is the PO's solution, I neglected to take a pic of my revision. 

Make sure you get the cover/wires sealed when you close it up,  these get water in them and the whole lot corrodes.

[TAR]

Use a pair of tweazers or flatnose pliers to gently draw the copper strip flat again, then you can put a slight curve back on it. I did this with a set and managed to get a good working contact again.

[peteyg]

I drilled out the rivet in the end, properly flattened the strip and screwed it back in. Turn's out it was all a waste of time as the motor itself is buggered! Still, pleased with the initial result...flat as a pancake!

[TAR]

The module that you have there were originally available as replacement parts (I have 2 new boxed ones) they are now long obsolete. Its worth keeping as they are more prone to problems than the motors themselves.

The motors themselves are quite basic are you sure its broken?

Did you test the diodes, they are known to fail?

[peteyg]

When the headlights are switched on the motor runs fine. Turn them off and the motor winds down maybe a quarter of the way. Shake the motor (whilst disconnected from the pods) and it winds back a little more each time I shake it until it finally reaches its original position. All the wiring seems to check out but internally, bits are falling off the windings and one of the brushes was missing chunks.

Not a fan of electrical stuff so how do I check the diodes and would they be likely to cause these symptoms?

Thanks for the advice so far,

Pete

[Andyww]

The motor is doing the same thing when raising and lowering the pods, its moving the same way. So it sounds like something common to one direction which would be the contacts on the aforementioned strip, or bad contact on the switch/relay wiring.

Could be a diode but they usually either go completely short circuit or open circuit. They can be tested with a multimeter or simply use a 12V test lamp in series with the diode. Should light one way but not the other.

You can easily test the motor itself by connecting the 2 motor wires direct to a 12V supply. As Tim says, they dont often fail as they get so little use compared to the same motor on a windscreen wiper. Running the motor for a while would probably clear off any corrosion on the commutator etc.

[johnpwalsh]

So, would this contact strip be the casue of one light coming up  but not going down again.

 

[TAR]

Yes it could, if one end isn't making a good contact. The motor is powered via that contact (at one end) and it stops because there is a nylon pin which breaks the circuit as the motor turns. The next time it  needs to move, its powered by the contact at the other end. If this isn't making a good contact, the motor wont move. 

Have a look here for an explanation of the circuit - http://www.wedgeneering.co.uk/TVR%20390SE%20p6.htm

[peteyg]

23 hours ago, johnpwalsh said:

So, would this contact strip be the casue of one light coming up  but not going down again.

 

Absolutely.

[johnpwalsh]

Thanks Peter. Also found the lift arm has about 12mm of free play on it, so it looks like its been forced at some point in it's life. I am busy rebuilding an S1 that we have never had running before so finding loads of little niggles, as in the motor, missing earth wires, one light on dip not working, wrong bulbs in tail lights. Etc Etc. But now its up and running.

First pic as found. Second is 95% completed. Almost 100% UK S1 spec, but still left hand drive.

[skiing]

I know this is probably sacrilege but I do quite like the rear louvres... I would love a set for my S3

[LJR]

I’m having a battle with my lamp pods constantly flapping up and down on dipped beam. They don’t do it on flash or main beam.

I opened the motors as shown in the picture above and one of the contacts for the switch did look a bit suspect so I put some string under it and pressed the strip against the contact while pulling upwards on the string to create a slight bend. This seems to have created better contact between the contacts but hasn’t cured the flapping motion.
 

I’ve also:

swapped the relays around

dismantled the binnacle light switch and cleaned it

bypassed the binnacle light switch

disconnected and checked the column stalk

none of these have fixed it and I’ve run out of ideas. Can anyone offer any suggestions?

[Choppa]

Not sure if your list covers this but have you checked the plastic pins inside the headlamp switch? Over time they can deform ever so slightly with the heat when the connection is made and prevent contact being made intermittently. This might be the issue and if you are careful you can dismantle the switch and replace the pins from a donor Lucas switch 

[Andyww]

There is a differece in the current path when main/flash is being used vs dip, but cant see how that can cause cycling on one setting but not the other. 

Maybe the reason it does not happen on main beam is the voltage drop is higher on the battery so the motors are being less "driven".

If thats the case it could be motor run-on. If either motor runs past the limit switch it will cause both to carry on running. Run on could be caused by two issues: The motor supplies are each earthed by a changeover relay when not running, which acts as a brake. If this is not happening it will cause this. Also the motors have end-float adjustment screws with locknuts on the end of the gear housing. If one of these has come unscrewed it will cause the braking effect to not work properly.

Also has the system ever been rewired? If someone has wired it according to the Turbo Esprit wiring diagram in the service notes it wont work properly as there is an error in the diagram. In fact the results of the error would be pretty much what you are seeing.

[LJR]

On 06/08/2022 at 21:14, Choppa said:

Not sure if your list covers this but have you checked the plastic pins inside the headlamp switch? Over time they can deform ever so slightly with the heat when the connection is made and prevent contact being made intermittently. This might be the issue and if you are careful you can dismantle the switch and replace the pins from a donor Lucas switch 

Yes I have and they are both fine, they look like new and are definitely applying pressure.

 

On 07/08/2022 at 09:08, Andyww said:

There is a differece in the current path when main/flash is being used vs dip, but cant see how that can cause cycling on one setting but not the other. 

Maybe the reason it does not happen on main beam is the voltage drop is higher on the battery so the motors are being less "driven".

If thats the case it could be motor run-on. If either motor runs past the limit switch it will cause both to carry on running. Run on could be caused by two issues: The motor supplies are each earthed by a changeover relay when not running, which acts as a brake. If this is not happening it will cause this. Also the motors have end-float adjustment screws with locknuts on the end of the gear housing. If one of these has come unscrewed it will cause the braking effect to not work properly.

Also has the system ever been rewired? If someone has wired it according to the Turbo Esprit wiring diagram in the service notes it wont work properly as there is an error in the diagram. In fact the results of the error would be pretty much what you are seeing.

I don't believe it has been rewired, certainly not in the five years I've owned it and the problem only occurred a few months ago. The wiring looks old and seems to correspond with the wiring diagram.

Where should I be looking to check the changeover relay and the earth connection? 

Is there a specific way to check the end float adjustment like a torque measurement?

[LJR]

@Andyww what is the error in the service notes wiring diagram?

[Andyww]

2 hours ago, LJR said:

@Andyww what is the error in the service notes wiring diagram?

Its on the connection to the changeover relay. Should look like this.