Thread: PROJECT 2A, New Headlight wiring up grade

Only problem I can see with this is my 2a and most of the others I have seen over the years, including two out of three my mobile parts supplies do not have H4 connectors on the existing headlights. My impression is that although the H4 connector is listed from suffix B on these were not fitted in Australia until the headlights moved into the mudguards in about 69. A lot of these may have been converted however - I have been thinking about converting mine, and probably put a relay in at the same time.

(I have no problems identifying wires etc, but others may have problems)

John

Hi John, I will eventually be making a kit available to accommodate other types of headlight fittings but there will be some additional work involved, as you have already workout.

The locating and identifying of the existing headlight wiring can be a difficult task for many people, so I have to makeup a step by step procedure that can be followed to make it a bit easier to fit the kits.

Which ever way you go, upgrading headlight wiring on older model vehicles, Landies or otherwise, does have a number of advantages.

The obvious and usually the main reason for upgrading, is to increase headlight out put but in many cases, the existing headlight switch not only controls the operation of the headlights but the switch also provides all the power, which usually leads to the switch melting and / or wearing out.

As the headlight upgrade removes this high current from the switch, it should mean that the switch never needs to be replaced again.

This alone will more than cover the cost of the upgrade kit.

Cheers.

Yes, I am aware of all this and fitted a relay to my 110 several years ago - this installation is very similar to your kit, but I cut into the wiring, partly because the incident that prompted me to do it was the failure of the H4 connector in the LH headlight (with standard bulbs). The main difference from your circuit diagram was that I took the power feed from the alternator output terminal. This is only six inches from the relay (4BD1 engine), where the battery is about six feet, and will have a higher voltage anyway under driving conditions.

John

Originally posted by JDNSW
I took the power feed from the alternator output terminal.

Hi again John, as the Defender battery is so far away, there may be some advantage to picking up the power for the lights at the alternator but as a rule I never pick up there because picking up all power at the battery tends to soften the change in charge requirements and lessen the jolt to the alternator.

Also note that all manufactures make their supply connections at or after the battery, including your defender, so there must be some reason for this.

By fitting adequately thick enough cable in the first place should result in equally bright lights.

Cheers.

Originally posted by drivesafe+--><div class='quotetop'>QUOTE(drivesafe)</div><div class='quotemain'><!--QuoteBegin-JDNSW
I took the power feed from the alternator output terminal.

Hi again John, as the Defender battery is so far away, there may be some advantage to picking up the power for the lights at the alternator but as a rule I never pick up there because picking up all power at the battery tends to soften the change in charge requirements and lessen the jolt to the alternator.

Also note that all manufactures make their supply connections at or after the battery, including your defender, so there must be some reason for this.

By fitting adequately thick enough cable in the first place should result in equally bright lights.

Cheers.[/b][/quote]

Supply connections on the County are at the starter solenoid as with many cars. The reason for the particular location is usually manufacturing convenience rather than anything else. Picking up power away from the alternator will not lessen the switching "jolt" to the alternator to any extent - it will only be lessened by the inductance of the extra wire, which is negligible. Certainly, if all wiring and connections are adequate and in good shape there will be no significant difference in connecting to the alternator, but if any of these are less than perfect, the alternator will be better.

You need to think of it the way the aviation industry does - the alternator supplies power, the battery is only a backup. Same system, just a different way of looking at it!
John

Sorry John but that couldn’t be further from what actually happens.

I’d be the first to state that you are going to have a higher voltage at the alternator but the battery acts as a huge capacitor.

Motors in particular, will draw high currents for anything from a few milli seconds to a couple of seconds when first starting up.

A standard 100w driving light globe will pull up to 200 AMPs for a few milli seconds, till the filament heats up, and if you are running 4 driving lights and you add in what your high beam is going to pull, then you are looking at well over a 1,000 AMP spike and it’s got to come from somewhere.

Both the cable running from the alternator to the battery and the battery, itself, act as a surge protector for the alternator.

By putting the light power wire at the alternator, you are not only defeating the battery’s benefits but the cable between the battery and the alternator now also works against the battery being able to supply this current surge.

You may like setting up that way and fine, that’s your choice, but for the long term effects this sort of set up has on the alternator, I go with the manufactures preferred set up.

Cheers.

I have to disagree with your reasoning again. The initial surge will come from the battery regardless of whether the connection is to the alternator of battery. The voltage drop at the alternator will be virtually the same in either case since for the time involved the inductance of the wiring is negligible - There will only be a somewhat greater voltage drop, but the timing of it will be essentially identical.
In fact, if you are running that number of lights, it is likely that the current initial current will be a lot lower than predicted simply because the voltage is a lot lower, so you will get a soft start effect. And unless the diodes on the alternator are very under rated, the effect is likely to be just as bad on the battery as the alternator.

But, again, in practice, if all wiring is adequate, and all connections good, it will make little difference whether the power is supplied from the alternator or the battery, except that in the case of the 110 there is about six feet less wire, and in all cases the voltage at the alternator will be higher than at the battery (even if not much), giving brighter lights. (Alternator voltage must be above the battery voltage since current is flowing TO the battery, even if the resistance of the charging lead is very small, as it should be)
John

Hi John, your mixing voltage spikes with current loads.

A current draw of 200 amps is 200 amps at 12 volts, 14 volts or at 4 volts, the only difference the voltage level will have is the lower the voltage, the longer it takes for the filament to heat up, the longer the high current draw will last.

The Alternator will tolerate this current surge but it appears like a dead short with such a higher current draw.

Whereas the battery is most definitely designed to cope with this kind of current draw, this is exactly how the starter motor acts on a battery.

Cheers.