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Sprint 4 headlamp problems

Posted: Tue Jun 27, 2017 6:10 am
by olr159w
Hi

I’ve nearly got the Sprint back to being roadworthy; not of course that there are actually any MoTs in Western Australia so its arguably academic in a formal sense, unbelievable though that is.

Two and a half issues left. Possible remaining camber issue on the offside but suspect all fixed by virtue of having the ride height correct. I hadn’t actually realised that a lower ride height causes negative camber so that whole topic may have been a red herring mis-identified prior to setting the ride heights. And then the exhaust downpipe needs replacing with a custom one that properly avoids the sub frame.

But the new issue is the headlights.

Turned them on and only the offside dipped beam worked. I assumed the nearside unit had therefore failed.

Then I tried main beam and they all lit up except the OS inner full beam bulb. My initial conclusion was some sort of earth problem causing weird effects. But I’m not clear on whether the dipped beam outer units have double or single bulbs? What happens re the outer lamps when main beam is selected – is it a second filament ?

I’ve changed my conclusion to the likelihood being that the NS dipped bulb/filament and the OS main beam/spot bulb have failed. However I can also see a high potential for tail chasing with this. Any wisdom regarding best course of action to most quickly reach an accurate conclusion would be appreciated.

Bonus question : I know I have a couple of spare lamp units in a box somewhere. How do I tell whether they are outer dipped+main or inner main only units?

Thanks

Re: Sprint 4 headlamp problems

Posted: Tue Jun 27, 2017 7:08 am
by GTS290N
Outers have twin filaments and three prongs on the rear of the unit, inners are single filament and have two prongs.
Dip beam the two outers are on, full beam all four are on.
4 x 55W and a nominal 12v that's close to 20 amps running through the stalk on the steering column, on tiny little copper contacts.
Fit relays!!! Now. These stalks are now very hard to come by. :)

Re: Sprint 4 headlamp problems

Posted: Tue Jun 27, 2017 9:52 am
by Carledo
What he said!^^^^^^

Best course is to take the units out (its not rocket science) and test them off the car with a battery and a couple of bits of wire. Take note of the wire orientation on the outer unit plug. Blue with white trace is main beam and blue with red is dip. black is ground for both. The inner units should work whichever way round you connect the 2 leads.

If it turns out that you DO have 2 duff sealed beam units, now might be a good time to convert to bulbs! (WITH relays!)

Steve

Re: Sprint 4 headlamp problems

Posted: Tue Jun 27, 2017 12:06 pm
by bazyerma
Hi

I say this on Rimmers for £120, has anyone tried it, or just made it up themselves?

https://www.rimmerbros.co.uk/Item--i-RM8100

Regards

Barry

Re: Sprint 4 headlamp problems

Posted: Tue Jun 27, 2017 3:04 pm
by cleverusername
bazyerma wrote: Tue Jun 27, 2017 12:06 pm Hi

I say this on Rimmers for £120, has anyone tried it, or just made it up themselves?

https://www.rimmerbros.co.uk/Item--i-RM8100

Regards

Barry
I just bought the headlight units from ebay and the rest is easy. A couple of cheap 12 volt relays and a s**t load of wire. I can't remember the price, but it was much less than what the brothers want.

Re: Sprint 4 headlamp problems

Posted: Tue Jun 27, 2017 3:42 pm
by olr159w
I've just checked and the two spare lamps I have are both dipped beam units - one looks used and the other brand new.

I should be able to swap some lamps in and out and find out whether its these units or some wiring problem.

It looks like new inner main beams are only 15 quid from Rimmers

Re: Sprint 4 headlamp problems

Posted: Tue Jun 27, 2017 3:57 pm
by xvivalve
Test the existing lamps by putting a current across the terminals; if they illuminate, they are fine! If they illuminate, then it's bad earth or faulty switch.


Always best to use a lower voltage on lamps that have stood a while; 12v immediately can cause them to overheat and blow!

Re: Sprint 4 headlamp problems

Posted: Sat Jul 01, 2017 4:25 pm
by olr159w
Result was that one dipped bulb had failed inside the sealed unit and one main beam had it's connector blade come loose. The latter was repairable and I happened to have one good new spare dipped beam unit so all is now good except I find one of the headlight adjusters has snapped. Separate thread for that .....