headlamp bulbs all blown

hi thanks for the replies. im obviously missing something here but I think the guy at wins told me that the bulbs are 60w each. total of 120w 120/12= 10 amps that is a hell of a lot of current. also does one have to put a resistor for the coil of the relay? otherwise surly it is a short circuit?
if he is running the lights off the alternator I guess he wont have lights with out the engine running???
coop
 
hi, knocked up a quick circuit diagram so we can understand each other



thanks
coop
 

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I used the wire from the shunt to the light switch and spliced two wires into it. One down the inside of one wing and one down the other. I used modern multi core which could handle 25amps. I used 4 relays, 1 for each dip beam, 1 for the inner mains and 1 for the outer mains. I fed the power wire straight the first relay, then piggy backed it to the second one. Same with the other side.

No single relay failing could leave me without lights.

I am not running the lights from the ammeter, but from the ammeter shunt which is a huge connector behind the dash. A large cable comes from the shunt to the light switch, use that cable. You can just pull it off the light switch and connect it to 2 x 25A wires to the relays, and one more smaller wire to the light switch (where the large supply cable went).

Don't know why you feel you need a resistor though.

Richard
 
Just found a wiring diagram I did for someone else when I wired mine a few years ago



Been a while since I did this :)
 

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hi thanks for the response. I was worried that u were dropping the full 12 volts across the coil of the relay hence practically a short circuit. (I can see this getting into node analysis and kerchovs theroms lol) what did u use for the earth side of the coil as I assume u used the existing lamp wiring for the switched side of the relay circuit.
coop
 
cooper1203 said:
hi thanks for the response. I was worried that u were dropping the full 12 volts across the coil of the relay hence practically a short circuit.coop
Click to expand...
Although relays may operate at a lower voltage than rated, generally a 12V relay requires 12V across the coil to operate correctly, in the same way that a 5V relay requires 5V, a 24V relay requires 24V etc... :D
 
cooper1203 said:
sorry meant thevinins not kerchov
coop
Click to expand...

Don't know much about Russian chess masters :?

I have just noticed that the wiring diagram I have posted is not quite right, as it shows the main beam relay running both left hand main beams, and the other one running both right hand ones. I actually changed this to run inners and outers from different relays so if 1 failed, you would still have a light each side of the car.
 
hi all quick update I have spent the morning looking for the missing wires. the whole loom is a real mess with wires running everywhere with bits of wire cut off. some wires going no where and others broken off by the looks of it. I did manage to find the nearside outer headlight wire but not the offside one. there are about 4 blue with white stripe wires there all running in diff directions and into different branches of the loom. there is no blue and green wire in sight. the only one we thought it could be went into a metal box with half a dozen connections fixed to the inner wing on the offside.

upshot is I have dipped only on the outers and main on the inners. this is how it was when the bulbs blew. I have an mot on Monday so I will ring the garage and make sure its acceptable I don't see why not as that was how it was when it was presented last year and passed.

I might end up having to save my pennies and get a new loom as this one is almost imposable to work out so many things have been added then taken away.

many thanks
coop
 
Personally, I wouldn't mention it to the garage just in case they're the pernickety sort (you may know them not to be, of course) who will tell you it's not ok even when legally, it may be.
You have dipped function & you have main beam function which is the MoT requirement. Unless the testers know the P6 set up, I doubt they would think anything unusual at all. A single headlight runs both filaments for main beam so I wouldn't think both running in separate headlights would present a problem.

If you tell them & they say it's not acceptable (even if that's not the case), you have to sort it immediately rather than at your leisure.

Harvey should be able to confirm or deny this.
 
From the test manual.

"3.
Check that the vehicle is securely fitted with obligatory headlamps, as follows:

. a matched pair of main beam headlamps, and

. a matched pair of dipped-beam headlamps

Note: Main and dipped-beam functions may be provided by a single pair of headlamps.
4.
With the headlamps on, switch between dipped and main beams checking that:
a.
each headlamp illuminates immediately it is switched to either dipped or main beam

b.
either:

. all main beams are switched off by one switch (dip switch) leaving a matched pair of dipped-beams switched on, or

. the main beam headlamp reflectors are deflected by a driver’s control, to make them dipped beams"

I can't see anything there that should cause a problem. Just because it's not the way the original set-up worked on the P6 doesn't mean it won't comply with the requirements of the MOT.

I'd suggest going to a classic friendly garage, as they'll have a better idea of what's needed, and they won't do your front wheel bearings up nice and tight......
 
Thanks guys that's pretty much what I figured. The owner of the garage I go to had a 3500s years ago and one of the other guys did his appretership on them and the sd1's. The issues comes when those two are on holiday and or busy as no one else has a clue lol.
coop
 
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