Bedford MW Headlights - Electrical testing

[44GPW]

Hi all,

 

Discovered last night that the headlights on my MW have stopped working. Bulbs seem ok and all other electrics are fine? I re-wired the whole vehicle with an Autosparkes loom last summer.

 

I have a tester but am no expert when it comes to automotive electrics. I used it to do continuity testing when i fitted the loom, but what settings do i need for testing if I'm getting a feed to the headlights? Can anyone advise.

 

Also, anyone have any idea where i should look first?

 

Thanks

 

Richard

[kpu121265]

If it is affecting them both (and other electrics are working) then it is something common to them both which is at fault, i'd be looking at the switch or dip switch if it has one.... (or the live feed to them).

Ken

[Tony B]

One or both headlights? The first place to check, and I'm speacking from experience, any fuse! (once stripped an entire set of units off before doing that) The next place would be the main switch, then the dip switch and earths. You should get voltage at each point. Do them in that order and you are following the circuit from scource at the battery up to the lights and to return. Other thing is which way was the blackout lights set? Remeber most military vehicles have a system to kill the head lights , easy enough to turn switch the wrong way.

[GeePig]

And remember to consider what you were last doing in the vehicle. Sometimes you disconnect something while working on something else, and then forget you have done it.

 

You can always make a continuity tester using a bulb in an old bulb holder (I think mine was an indicator bulb holder from a Triumph Stag), adding a pair of leads to it with some crocodile clips on the other ends of the wires. Clip one croc clip to a good earth and then test the connections on the feed wires progressively all the way from the battery to the headlamps, via the switches. If you want to get to a hard-to-get-to connector, clip the croc clip to a screwdriver and poke around with that. I always had one of these in my toolbox back when I was a mechanic.

 

Trevor

[44GPW]

Thanks both.

 

Its both that are effected. They have been perfect up to now. Mine being a later MW does not have the dip option, and the wires that go to the blackout switch on the panel are just joined on mine, again because its a later model. I'm happy about the switch position.

 

So on my tester, what should i be setting it at in order to check the live feed?

 

Thanks

 

Richard

[GeePig]

Thanks both.

 

 

So on my tester, what should i be setting it at in order to check the live feed?

 

Thanks

 

Richard

 

Not sure what type of tester you have, Richard, but presumably set it to DC voltage? One lead clipped to earth, the other to whatever 'live' feed you are testing.

 

Trevor

[44GPW]

Nor am i Trevor....lol.

 

Ok, thats great...should find my way now. I will post how i get on, on Monday.

 

Thanks all for your replys.

 

Cheers

 

Richard

[44GPW]

Hello again John,

 

Thats really interesting but doesnt answer why the lights have been ok until now, unless a fault occurs on the feed in the loom between the fuse box and the lighting juncion box. I cant see it but you never know i suppose?

 

Could just be a loose wire somewhere, on the switch itself maybe?? It was quite a struggle getting the panel wires in (thick loom and not a lot of room) so maybe i didnt nip the main light wiring up as tight as i should have done?

 

I will hopefully get to the bottom of it this weekend and post here what i find.

 

Thanks

 

Richard

[mike65]

OK you have had some sensible answers and now for the stupid questions.

No offence meant but I had a couple of friends who spent 2 hours trying to get a just serviced mini working only for me to point out the rotor arm was in the top of the socket set.

 

I work with a tester that lights up if there is a current. It is simple like me when it comes to electrics:D

 

You state you have power to the headlights. Is this at the bulb?

If yes, is there continuity through the connections.

Have you tested the bulbs? Have seen failed fuses and bulbs where the break is not clearly visible.

 

I have also been known to test using a meter set to volts if the simple test does not help.

That was how I traced my headlightproblem down to some fool connecting the wires wrong and earthing back via the dip circuit.

 

Mike

[44GPW]

Well after all that the problem (or problems) were very simple ones!! The left hand side had a bad bulb (element looked fine but it failed when tested. The right hand side had a bad bulb holder. The spring that pushes the contact in the bulb holder onto the contact on the bulb was weak and not pushing it up far enough. A small order to Auto electrical supplies and i should be sorted. Thanks all for your input. Cheers Richard