Forum:
Sorry about another light problem, i have read previous posts but cant find what i need to know.
Fourtrak F78 V Reg....light switch pos 1 side lights come on fine, pos 2 right headlight fine but left dim. Operate main beam and left comes on but right goes dim.
Was going to try bulb but guy in local car accessory shop tested it and was fine, he said why dont you just run new earth to each light, which i'm happy to do, but i read on here somewhere that they use a switched earth? and does not go to vehicle body.
It would help if i knew what colour was supposed to go where on rear of bulb,...the thing is they were like it when i bought it recently and someone has put new connectors on to bulbs, so i would like to make sure they are the right way round. But my lack of knowledge is not helping. It seems every combination i try, something does not work!
I have cleaned the connectors inside the steering column as i read that is a common fault.
PLEASE HELP my garage is tiny and bloody freezing! I would almost rather do the fuel lines again rather than this!!
Thanks in advance Steve
headlight bulbs allways have
headlight bulbs allways have an earth at the bulb holder, if its a three terminal bulb like a 472 then one is earth the other two will go live when dip or main beam are on respectivley, ident the earth one and "provide" it with an earth direct from battery, then check operation, if problem cured then do a proper repair, what you are describing does seem to be an earting issue, hope that helps, kirk
ive just had a peer at some
ive just had a peer at some wiring diagrams on a cd i got off ebay years ago.... they show the side, stop and indicaters wired conventionally, power, switch, light, earth... the headlights are shown as a switched earth... power , headlight relay, lamps, then two wires back to the two contacts (main and dip)on the column switch, then down to earth . horn is also shown as a switched earth.
so there are three wires connected to the headlight bulb... one should have power on it from the headlight relay when the headlight switch is in the main or dip position. this will have to be connected to the common terminal on the bulb (the one which is earth on a normal car) the other two should be shorted to earth (via the switch) when headlight switch is on... if you get them the wrong way round the dip and main will be swopped over.
good luck
Thanks Richard, that would
Thanks Richard,
that would explain why i'm confused, i wont give up just yet then! will give it another shot tomorrow.
just tested my sporty wiring,
just tested my sporty wiring, one terminal remains earth at all times, the other two live up depending on dip or high beam-the one that stays earth is the one to give a permanent earth to[just to test]
DONE IT !!! What a swine that
DONE IT !!!
What a swine that was. Turned out to be contacts at steering column, but mainly a faulty bulb connector, doesn't seem possible something so simple can be faulty, probably why i overlooked it.
Although this switched earthing didn't help.
All bulb terminals become live at different points in the lighting cycle, thats what really through me.
Anyway thanks for all your help and comments.
Steve
hope we were of some help,
hope we were of some help, realy dificult without the car in front of you!
Thank you for your reply
Thank you for your reply Kirk, sounds logical, but what i'm confused over is..as you look at the three pins on back of the bulb (from the rear) the left pin is ground (i think), but when i put my tester on this pin, its live. Hence me being unsure of earth. Steve
Bulb pins in wrong location.
You have put the bulb into the holder with the pins in the wrong location. The circuit is illuminating the wrong filament within the bulb. I did same a few years ago.