HELP PLEASE - Lightforce lamp electrics

Eyefor

Well-Known Member
Any electricians on here please?

My lightforce bulb died so I replaced it with a new one - but now the lamp will not work on the suction arm.

If I put the two wires across a 12v battery the lamp comes on. I have also put a voltmeter at the business end of the handle and I have 12.96v - but the light will not come on when connected to the same wires??

I have tried various combinations and different connectors - all to no avail.

Any ideas please as to what I am doing wrong?

Thanks in advance.

Iain
 
Try changing the seating of the bulb, if i remember right some need to be seated right down while others need to be lifted slightly off the seating so there is a gap between the bottom of the bulb and the housing.
 
If you have used crimps that you have crimped the copper cores and not the rubber sheath. You could also check the continuity of both wires to make sure the cores are not broken .

Provider
 
Try changing the seating of the bulb, if i remember right some need to be seated right down while others need to be lifted slightly off the seating so there is a gap between the bottom of the bulb and the housing.

If you have used crimps that you have crimped the copper cores and not the rubber sheath. You could also check the continuity of both wires to make sure the cores are not broken .

Provider

Many thanks for the replies and I will check out both of these tomorrow (& report back) - but why would I get a lamp that works connected straight to the battery and doesn't work when connected to wires showing 12v+ on the meter.

Slowly going mad........
 
Test the NEW bulb, just because its new doesn't always mean its a good one. You could also try bypassing the switch as these sometimes fail.
ATB Gaz
 
If I put the two wires across a 12v battery the lamp comes on. I have also put a voltmeter at the business end of the handle and I have 12.96v - but the light will not come on when connected to the same wires??

This isn't clear to me, but I've never seen a lightforce lamp before so...

Which two wires do you put across the battery? Are these two bare copper wires that connect directly to the lamp and you are just holding them across the battery?

"The busness end" where is this and how is it related to the two wires mentioned above? For example do they plug into it?
 
This isn't clear to me, but I've never seen a lightforce lamp before so...

Which two wires do you put across the battery? Are these two bare copper wires that connect directly to the lamp and you are just holding them across the battery?

"The busness end" where is this and how is it related to the two wires mentioned above? For example do they plug into it?

The two wires I put across the battery are connected direct to the lamp and are (something like) 2 core x 1mm plastic coated. Doesn't matter which way round I touch the wires to the battery - the lamp comes on.

The "business end" is the top end of the suction arm where the lamp sits and the driver can use the swivel mount to direct / rotate the lamp as required when lamping. The sequence of the wiring is (for various reasons) crocodile clips to battery / bottom multiblock / switch (in base of handle) / top multiblock / lamp. At the top multiblock with switch on I have 12v+ on a meter but the lamp (when connected) will not illuminate.

Aaaaaargh.

Daytime shooting is so much easier!
 
Welcome to the world of Lightforce wiring and switches.

Sounds to me like there is possibly a breakin one of the wires which is causing the continuity issue.

Also did you check the old bulb is actually blown?

Is the new bulb OK, flick it with your finger nail just to see if the filament is Ok.

Is it a vertical or horizontal filament bulb?

Had numerous issues with this problem, you may need to resort to testing every section of the wiring, and wiggling it you may then pick up the wire which is broken. Helps to have crodile clips to attach to ends of wires.

Also look very closely at the switch, classic place for fracture/soldering to go.

I susupect like most lightforce users you will end up rewiring the whole lot.

Light bulbs direct is good source for bulbs.

D
 
Welcome to the world of Lightforce wiring and switches.

Sounds to me like there is possibly a breakin one of the wires which is causing the continuity issue.

Also did you check the old bulb is actually blown?

Is the new bulb OK, flick it with your finger nail just to see if the filament is Ok.

Is it a vertical or horizontal filament bulb?

Had numerous issues with this problem, you may need to resort to testing every section of the wiring, and wiggling it you may then pick up the wire which is broken. Helps to have crodile clips to attach to ends of wires.

Also look very closely at the switch, classic place for fracture/soldering to go.

I susupect like most lightforce users you will end up rewiring the whole lot.

Light bulbs direct is good source for bulbs.

D

Hi.

Many thanks for the input.

I have switched bulbs (horizontal filament Osrams from t'interweb at £2 each) between working ones and still the same result. Daft thing is if I wire direct to a battery it works but via the handle it doesn't - although I have 12v+ at the wire ends?

If I put the meter in to the lamp holder I still get 12v but when I insert the bulb - nothing.

I also suspect I will end up rewiring the whole lot - but how to get the lampholder out of the handle? It is pop rivetted in?

UPDATE

The problem is definitely in the T handle 'cos I have now wired the lamp to a battery using the old Lightforce flexi cable (& not the 2 core household style cable that came with the - secondhand - T bar) and the lamp works.

Rewire of T Handle I think!

Thanks for all input.
 
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Yes it is rivetted in with an alluminium rivet, just be carefull how you drill it out.

Come to think of it had to do this on mine, I think it was a cracked soldered connection. Not too difficult a job ( was on a hand/scope mounted version) bit fiddy. Best to use a short ally rivet replacement just in case.

D
 
Yes it is rivetted in with an alluminium rivet, just be carefull how you drill it out.

Come to think of it had to do this on mine, I think it was a cracked soldered connection. Not too difficult a job ( was on a hand/scope mounted version) bit fiddy. Best to use a short ally rivet replacement just in case.

D

Rewired the handle & found (crap) scotchlok connector with poor connection was causing all the trouble and now 100% working.

Very grateful for all inputs on thread and PM's.

Let there be light!!
 
HI there this is not just a fault with lightforce but you will find that you can get 12 v reading with no load on it .
But more than likely you have a poor conection that only shows when under load.
From a motor mechanic that see's this with 12v systems a lot. with this poor conection It will offen
get warm or even fizz good luck.
 
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