bonnet 8 point connection

[david muir]

Busy doing headlamp relay upgrade........is there a wiring diagram of colour to number in either manual-can't find!! Everything worked before now chasing Red/yellow to put feed in from alternator. G
uess it doesn't matter as long as everything matches . Horn goes to centre pin-correct??


{1964 3.8L, just on change over to 4.2}

[abowie]

Are you talking about the 8 pin plug, or the bakelite connector in the bonnet itself?
The plug wires are numbered in the connector from 1 to 8. If you look on the wiring diagram the wires are marked with the correct number, in a circle. So for example low beam is 3, high beam is 2, etc.
The bakelite connector needs a little thought to get the wires, particularly the earths, correct. At first it seems there aren't enough slots, but a bit of trial and error will get it right.
The red yellow wire is for fog lamps; unless you have them fitted you needn't worry about it although I have found uses for it in the past, either as an additional earth wire or to bypass another wire when it was broken inside the loom.

[christopher storey]

David - I am puzzled ( and a little bit concerned) about your reference to an alternator feed . This can have no valid connection to the bonnet plug at all?? In any event , if you are using an alternator on a 3.8, you really need to use the early 4.2 circuit diagram

[david muir]

Sorry Christopher, my question wasn't worded very clearly! Doing the headlamp /relay upgrade and (think it was suggested on here?) was going to take the large feed to the front lamps from the spare +ve terminal on the alternator rather than go back to the battery.

[christopher storey]

David : unless I have misunderstood the scheme, I don't like that idea at all. It seems to me that it would leave you essentially with an unfused supply to the lights at all times when the engine was running . Also, if for any reason e.g. broken drive belt the alternator ceased to transmit current, at night you would have a sudden loss of both main and dipped beam which if the car was in motion could be highly dangerous . Would it not also result in the light intensity continuously varying with alternator output voltage ?

[mark10337]

Adam: Can you remember where the red/yellow wire comes out in the main loom? I've seen it on the connector to the bonnet, just never noticed the other end of it anywhere

[MarekH]

The bonnet loom red/yellow wire reappears behind the centre panel of the dash.

I think Christopher has almost certainly misunderstood the proposed wiring alteration:- any sensible alternator wiring methodology powers the the battery brown wire and hence the whole car at any revs higher than idle. The alternator's regulator stops light intensity from varying, as the alternator output is regulated to typically 14 to 14.4 volts. When an alternator fails, you are left with battery voltage, rather than nothing. I don't think anyone is envisaging a new unregulated and unfused output from the alternator.

It would be sensible to fuse the front light feed from the alternator.

kind regards
Marek

[Heuer]

I suggested using two fuses in the headlight upgrade (one per headlight) so that if one fuse did blow you would not be left without lights. As Marek says, using the alternator post or battery post makes no difference as they are part of the same circuit. I think the confusion here is there is no 'spare' alternator post - headlight feed should be on the same post as the brown high capacity cable to the battery.

[david muir]

Have now completed headlamp/wiring/relay upgrade and am now 'tidying' the headlamp fitment as per info. on this site. Before upgrade my headlamps had adjusters at 9 and 12 o'clock (from front of car) and this allowed the headlamp to be located(on its 3 lugs) correctly in the retaining rim and plate. Now, having moved the bowl/gasket/ adjusters to the 'correct' 3 & 6 o'clock, the headlamp will not locate in the rim and plate!!
Is it definite that adjusters should be at 3 & 6.?[ car is late 3.8 , RHD]. I have seen mention , on here , of adjusters at 9 & 12.

[Heuer]

Adjusters should be at 3 & 6 o'clock if you have the correct parts.


Check these posts:

viewtopic.php?p=40168#p40168
viewtopic.php?p=49432#p49432

You need to make sure the bowls and retaining rings all match up. Holden sell bowls, rings or a complete unit with adjusting screws at 9 and 12 o'clock : https://www.holden.co.uk/displayproduct ... e=54520553

[david muir]

Okay, got all correct parts-it's the lamp retaining 'cup' and rim that required 'fettling' so that the Cibie unit (with three lugs not at 120 degrees!) would sit and locate as it should as it should! Nearside headlamp now good, hopefully offside one will be as straightforward.
Thanks for prompt response.

[Heuer]

Interesting you can get the Cibie headlamp units to fit as I could not with the flat backed housings. Are you using non standard ones?

[david muir]

they're Z beams (or what used to be called that!). No problems getting them in(read your historical post) . Great headlights, fantastic cut-off, way up nearside verge. I've never measured the height of the headlamp but will when I take the next one out!

[david muir]

David, Just removed O/S headlamp and its 'depth' (convex of glass to rim of bulb holder) is approx. 4". Once bulb in, depth is approx. 5"
Now tidying up wiring on O/S, have got new 5 way connector but need a photo of where it mounts-anyone??
Sure I've seen a photo somewhere but can't find it now! Wiring was just a mess of insulated connectors(hate them!) and sleeve connectors.

[MontanaDiver]

I understand the rationale behind using two fuses for the headlamps, however would there be a disadvantage to using two circuit breakers instead?
Just thinking about the issue of losing the low beam until I can replace the fuse versus the circuit breaker allowing the lights to work after a temporary short occurred.