Sealed beam headlights

[milothedog]

Surely it isn't difficult for an electrics expert to work out which of the three terminals is earth, dip and main using a multimeter and a 12v supply......

That's how I did it when wiring up my 4xH4 system.

PMSL

[milothedog]

Further to my earlier "Unidentified Black box" thread and ensuing headlight problems I decided to examine the connections to all the sealed beam units.

The two Lucas inners (full beam only) are OK but discovered that they were wired with red and black feeds which of course is non standard. Furthermore guess what the black is live and the red is earth Took me some time to conclude this with multimeter

Following the wiring back reveals crimp connectors just before wiring diappears into sheathing where (difficult to see) it appears that the correct colouring is restored.

My main question relates to the 2 outers. These are Ring units with dip and mainbeam filaments. In their intended application these should I assume be wired for dip beam only.

My memory confirmed by searches says that on these SB units viewed from the rear with the centre connector uppermost Then:

The LH connector is Earth

The centre is Dip

The RH is main

With my LH (N/S) outer I have no idea how it was connected as the connectors fell off on removal. I have reconnected it as above

When I removed the RH (O/S) outer SB unit it was connected with Earth on the left but RH as 12v feed (i.e. Main beam?) There is also a second independent earth connector in the housing (apparently not connected) Have established that both black wires in this case are truly earth.

We have only owned this Stag for about 3 months or so but it has an MOT dating from only a couple of months before we purchased in which I would have thought any lighting errors would have at least been advisories.

Could forumites confirm that my connection ideas are correct in the context of these Ring units and comment on the correct way that the outer RH(O/S) unit should be connected..

It also occurs to me that these outer units have unused main beam filaments. Why are they just not connected in parallel with the inner main beam units?

That may have something to do with the way sealed beams are checked on an MOT (on main beam).

[HersnotHis]

Surely it isn't difficult for an electrics expert to work out which of the three terminals is earth, dip and main using a multimeter and a 12v supply......

That's how I did it when wiring up my 4xH4 system.

Yes I could do it that way but had hoped someone on here with recent experience of SB units would save me the trouble - all I want is confirmation that my understanding of the physical connectors is correct.

[HersnotHis]

Surely it isn't difficult for an electrics expert to work out which of the three terminals is earth, dip and main using a multimeter and a 12v supply......

That's how I did it when wiring up my 4xH4 system.

Yes I could do it that way but had hoped someone on here with recent experience of SB units would save me the trouble - all I want is confirmation that my understanding of the physical connectors is correct.

[HersnotHis]

Not hard to find out

Google is your friend........

Thanks yes I found this on Search. See my OP but seem to remember that not all SB units were the same ? ? Just wanted confirmation that these 5.75" Ring units were the same. - thats all!