Dim Dull lights front and back, checked earth!

Post by **ali thommo** » 01 Jul 2008, 19:56

Ive got a T25 1986 1.9 petrol. Just got back from Glastonbury after driving there with virtually no lights! Heres what ive checked:

- Cleaned all contacts on battery
- Checked battery with a meter getting around 12V
- Checked earthing "roses" behind fuse box
- replaced bulbs

Both the front and rear lights are dull as are the indicators, everything else works fine i.e. stereo, wipers, water jets etc. I was hopin someone could point me in the right direction as im supposed to be going to wales this week and dont fancy another scarey ride! javascript:emoticon(':shock:')

I was wondering a few things, anything to check on the alternator? The main thing i was wondering is where all the earth straps are and what they look like, i believe theres one from the gearbox to chassis? I cant see one but dont really know what im looking for ( a picture woiuld be great!)

Anyway any help would be great and if i solve the problem ill report back on what it was because i cant find any information that solves this!

Thanks All.

Post by **big red bus** » 01 Jul 2008, 21:21

Have you checked the charge rate. You say that you have 12v at the battery. You should have 12v when engine not running and when engine running around 14v is a healthy figure. If it is 12v alternator not charging battery although problem does sound more earth related. Have you removed headlights or any lights and checked put a sepearte earth onto the lamp/light. If lamp light up bright as normal then it is a earth fault.

Post by **ali thommo** » 01 Jul 2008, 21:52

Hiya, yes ive took the light out and just connected the bulb to the connecter (discarding the outer metal shell), i have then crocodile clipped the earth to the metal surround on the bulb, started the engine and nothing changed then I removed the wire to confirm and still nothing changed, thanks for the advise on the alternator though ill check that tomorow. If the alternator is reading below 14 when the engine is running does this mean a new alternator or just replace the brushes? The belt on thealternator is not too slack. Thanks again.

Post by **big red bus** » 01 Jul 2008, 22:21

check the obvious first. presumable the belt is on and tight, wiring to alternator is present and connected,
if you are getting a reading lower than 13.5 then alternator is not charging suficently. most likely just to be the brush pack or the regulator pack.

Post by **ali thommo** » 02 Jul 2008, 22:17

Hello spent another 4 hours trying to diagnose the lights! double checked the earth with a multi meter, resistance was a little high cleaned it up - not made much difference. The battery when engine is not running was just over 12V something like 12.44V i think, when the engine was turning over the reading risen to 13.74V so no problems there. Really confused, cant understand why all the lights would be dim, even when changed. Is there anything else i can try?? The help posted has been great so far and ive ticked of quite a few things now, kind of run out of things to try so any suggestions would be great.

Post by **Mocki** » 02 Jul 2008, 22:20

ok, what voltage are you getting at the tail lights , both engine running and not?

could be dirty fuses
or iffy light switch
or bad feed to switch
bad battery connection

if all the earths are good, it must be a live problem

Post by **Fritz** » 02 Jul 2008, 23:12

My turn to back up our lad M0cki, I 'd be having a closer look at either the side-main lights switch on the dash or the Dip/Main beam switch on the column sound to me like one or both is suffering from a bad connection/getting hot or burnt out.....

Regards

Fritz,,,,,,,,,,

Post by **ali thommo** » 02 Jul 2008, 23:42

2 more things to try tomorow! ill double check the voltage at the lights, got obsessed with earths today! Im liking the sounds of the switch having high resistance, deffo check that tomorow. Just ordered 25 spade connectors from ebay thinking about changing all the spades on the earth crown and the ones on the light sockets. Once again ill post back the results we`ll crack it!

I take it the reading at the bulb end of the lights should be around the same as i read on the batttery, i.e. around 12.44 idle and around 13.74 turning over? Or is this wrong?

Post by **ali thommo** » 03 Jul 2008, 12:50

Well thats annoying, checked all switches with multimeter no high resistance on any of the points. Checked the red wire from end to end, no resistance. still not checked the voltage at the socket end of the light will check that today if the thunder that i think i just heard holds off! Suppose knowing the voltage at the socket end of the light will be informative.

Post by **ali thommo** » 03 Jul 2008, 20:30

Ok pretty much tried everything now. i tested what voltage i was getting at the light socket with 1 light unplugged and both lights unplugged (main beam)

while engine was running i got:
1 bulb in: 11.64V
0 bulbs in: 12.98V

This all sounds good to me! So all i can put it down to is the bulbs: ive checked them and the 55/60 wat H4`s they are what there supposed to be.

heres my final verdict! i think its either the spade terminals having a poor connection or the small reflector that sits on a stalk and covers the bulb, i think its a reflector, heat sheild, anti glare thing. Should this be chrome/highly reflective? mine is kinda dull metal.

Anyway as ever anymore input would be great! feels like its dragging on a bit now!

Post by **Mocki** » 03 Jul 2008, 20:39

ok, can i just verify something here?

are we talking about dim headlights, or all lights?

if it is just headlights, check the dim dip resistor nessled behind the o/s headlight ( if you have one) also, try running a temp wire direct from the battery to the headlights ( spliting it into two as near the headlights as poss, with the van loom unplugged) and see if it much brighter....

that seems to be a bit big a voltage drop to me.........

Post by **VWCamperfan** » 03 Jul 2008, 20:52

Unlikely I know but make sure you have got 12 volt lamps in place. You can get 24 volt versions of all the lamps you mention and this will give you a very poor light.
The wattages will still be the same though so it may appear correct just by looking at that rating.

Post by **ali thommo** » 03 Jul 2008, 21:08

Everytime i post here i think ive run low on possibilities and then people post more ideas! Ill double check the voltage on the lights tommorow. I should have thought of running a direct line to the lights again ill try that tomorow. The only thing that keeps confusing me is that all the lights are dim including indicators! Anyway thanks once again ill check those things tomorow.

Post by **Mocki** » 03 Jul 2008, 21:18

i would be swapping a couple of bulbs for known good 12v ones, say a indecator and a taillight.......

although i dont for one moment think its 24v bulbs in the indecators, or they wouldnt flash the right speed, possibly

Post by **AngeloEvs** » 03 Jul 2008, 23:12

You seem to have a large voltage loss at the bulb when drawing current from the battery, my first instinct is the positive feed from the battery to the Fuse panel. You state that the voltage falls to somewhere between 11 and 12V when you connect a bulb. Switch the engine on and measure the voltage across the battery with no lights and then repeat the measurement with the lights on. If you are measuring around 13V /14V(across the battery with the lights on and the engine running) then you should be getting a similar reading across the bulbs. If the reading across the bulbs is less then you may have a problem with a common feed wire but any component/connection that is common to the lighting circuit could be at fault. Also, check the voltage across the bulb terminals and then compare the reading by placing the meter across the live conx of the bulb and to a good chassis earth point, if there is no change then it is unlikely to be an earth fault.

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Dim Dull lights front and back, checked earth!

Dim Dull lights front and back, checked earth!

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