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        General >> Problems >> Nearside Dipped Beam Headlight Fault
        
(Message started by: Technology2005 on Apr 25^th, 2013, 12:22pm)

Title: Nearside Dipped Beam Headlight Fault
Post by Technology2005 on Apr 25^th, 2013, 12:22pm

On the other half's Scorpio 2.0 Ultima the nearside headlight decided to stop working on dipped beam. No problem I thought I'll change the bulb. The bulb when removed looked perfectly ok which was a bit disconcerting.

Fitted a new bulb and, yes you guessed it, no dipped beam! ???

A quick check in the main fusebox and confirmed that fuse 5 is ok. Out with the multitester....

The ground for the dipped beam bulb is fine. With the lights switched on and the connector off the bulb I get around 12V at the connector.

Plugged onto the bulb I get no volts. I compared this with the offside headlight and of course as expected I was getting the 12V with the connector on or off the bulb (otherwise it would not illuminate).

If I put main beam on and swap the connectors on the dipped beam bulb and the main beam bulb the dipped beam bulb works and the main beam does not.

It would seem there is a short to the headlight bulb connector when the lights are switched on? But this same short does not stop voltage at the connector if the bulb isn't physically connected.

I'm going to swap Relay 3 from the battery side fusebox for one from my Scorpio as a check, but does that relay even energise the dipped beam circuits independently?

The only other thing I can think of, apart from hunting down a short, is to change the light control switch in the dashboard but the fault is only with dipped beam and only on nearside. Sidelights, mainbeam and parking lights are all fine.

Any thoughts? If a short where is the most likely place to start. I do have spare headlight units if necessary but I don't think the issue is the headlight itself unless there is a problem where the multiplug connects.

David

Title: Re: Nearside Dipped Beam Headlight Fault
Post by PJDavis on Apr 25^th, 2013, 1:15pm

I had the exeact same fualt on my second car, it's a 2 ltr as well. The only way I could solve the problem was use a wee short jump-wire with a female spade one end and a piggy-back spade the other. Used it to take an earth from the main-beam. Nothing else would work!
Peter

Title: Re: Nearside Dipped Beam Headlight Fault
Post by Mike H on Apr 25^th, 2013, 1:57pm

on 04/25/13 at 12:22:41, Technology2005 wrote:

With the lights switched on and the connector off the bulb I get around 12V at the connector.

Plugged onto the bulb I get no volts. I compared this with the offside headlight and of course as expected I was getting the 12V with the connector on or off the bulb (otherwise it would not illuminate).

This suggests resistance in the wire somwhere, can't get enough current through for the bulb, so ends up looking like a short to ground (no Volts).

Could be fixed with a new wire in parallel?

Title: Re: Nearside Dipped Beam Headlight Fault
Post by Simmo on Apr 25^th, 2013, 2:09pm

Check out the lighting switch. There is a known issue with Pin 15, from memory. It overheats. Look at the connector also which attaches the loom to the switch as it may show signs of scorching. :)
The details for removing the switch are Here (http://www.fordscorpio.co.uk/intbasicelec.htm)
A better detail is here (http://www.fordscorpio.co.uk/manual/electrical/intbasic/Switch-Light.pdf) at para 10. This latter is linked from the Fault Finder page on the site.

Title: Re: Nearside Dipped Beam Headlight Fault
Post by Bikerdon on Apr 25^th, 2013, 5:38pm

I had a similar problem, but with the offside dip beam, solved it temporarily with the separate earth wire trick. When I investigated further it turned out to be the dim dip relay had packed up, replacing that sorted it out and I was able to ditch the temporary earth. I know only some model year Scorps have the dim dip circuit. Mine is a 1997 P plate 2.0l ultima which does have it. HTH.

Title: Re: Nearside Dipped Beam Headlight Fault
Post by Glyn on Apr 25^th, 2013, 5:40pm

Are the dim=dip affected as well?. Had same problem in the past which turned out to be faulty main fuse box.

Title: Re: Nearside Dipped Beam Headlight Fault
Post by Technology2005 on Jul 10^th, 2013, 11:43am

Had an auto electrician look at this and (after much head scratching) he traced the fault back to a faulty fusebox....oh joy :P

Luckily I have a spare one but not looking forward to the contortionism required (from what I have read elsewhere on the site) to change the pesky thing!

In the meantime he ran a feed from the OS headlight to the NS and this enabled the car to get through the MOT.

David

Title: Re: Nearside Dipped Beam Headlight Fault
Post by amigafan2003 on Jul 10^th, 2013, 9:28pm

TBH if you've got a workaround and no other faults, I'd just leave it as it is.

It's not like we've got cars worth £10k and we need to keep them original. We're all really just buying time before they finally get scrapped.