T4 Headlight Issues

[OzFitzy]

My 2000 T4 (LWB 2.5 petrol auto) has two issues with headlights.

[ 1 ] Poor output.

[ 2 ] The dip switch won't latch.

[ 1 ] It has appalling headlights. It is like having a candle in there (and reminiscent of the output found on early 6V Beetles).

Even highbeam is not up to the low-beam output of most vehicles.
High beam penetration is so bad that at night on rural roads I can only travel safely at 80kph on a road I know and 60kph on a road I'm not familiar with.

Just wondering what other have found or done to improve this.
I think it uses H7 bulbs and wonder what bulbs I should change to.
I wonder if the reflective area has gone dull?
A HID kit is probably an overkill.

[ 2 ] Also the highbeam will not latch on - although I found last night that if I first put the turn indicator on, it will latch high beam and then turn off the turn indicator and it stays latched.
Not good, but it beats holding high beam on with the flasher stalk for a one and a half hour trip as I did the first night before I found that workaraound.

In fact I found (once I got it latched on high beam) that I could leave it on and not one other driver flashed me for not dipping - so poor is the output.

At first I thought it must be a faulty relay, but my T4 doesn't use one.

So it must be a mechanical wear point in the switch.
Anyone else found this?

[Brian Considine]

I hope someone has a solution - my similar aged T4 has the same pathetic headlamps, dip & main.

However, there is an almost 2v drop between the battery terminals & the headlamps (measured with & without the engine running - the 2v drop is the same). This could be the reason why the lights appear to be dim.

I suspect that the loss may be through the wiring - there does not appear to be any relays in circuit. I have thought about rewiring them with relays but it may upset the monitoring circuits !

As an aside the van had an appetite for rear stop/tailamp bulbs, so I fitted a pair of LED replacements - problem cured, but when the lights are on the engine management light flashes ! - when I tow a trailer (putting the load back onto the circuit) the light no longer flashes !

[OzFitzy]

As an aside the van had an appetite for rear stop/tailamp bulbs, so I fitted a pair of LED replacements - problem cured, but when the lights are on the engine management light flashes ! - when I tow a trailer (putting the load back onto the circuit) the light no longer flashes !

Brian,

I'm assuming that since the load of trailer lamps fixes the situation, without the trailer the LEDs are probably a lower resistance and seem like a blown globe to the system. My guess is you need to measure the ohms resistance of both the original bulbs in circuit and the LED lamps. You might then be able to add an appropriate resistor at the LEDs to bring the load up to what the engine management system expects.

I must look for voltage drop on my headlamps too. No doubt introducing a couple of relays would overcome that drop - but I wonder if the headlamps were any good when the vehicle was new?

I wonder what the alternator output is? Maybe a couple of driving lights would help (if the alternator can handle it).

Cheers
Wayne aka Oz Fitzy

[Brian Considine]

Hi Wayne - I have though about adding some ballast resistors but have not really got round to it.

Most T4's have decent alternators so I don't think it would be a problem adding a couple of driving lamps.

A friend of mine who has had a number of T4's told me that not one has had decent lights - & his were all new when he got them !

As most of my driving is on motorways & well lit roads I'll probably leave it for now.

Maybe you solution (albeit illegal ?) would be to relay the circuits & fit 100/150w bulbs ?