...any ideas how I should start to try and fix it?

Never had it play up in any car before, no idea where to start

sidelights/parking lights (the 5W ones) come on as normal, as do the dipped and main beams, but no sign of the dim dip when ignition is on.
Its an H plate Mk4 Escort so should have it.

 

Have you tried new bulbs 1st ?

 

That's not the way it works!

Somekind of low voltage is applied to the main 55 watt bulbs so they glow when on the sidelight setting alongside the 5 watt bulbs. And as above all other functions are ok.

 

stalk will prob be faulty- common thing on the mk3 and 4.

THey're not the same stalk though

 

Wouldn't have thought it would be the stalk as the sidelights come on ok, just not the dim dip feature.... would have thought this was controlled by a relay or similar elsewhere.
Have you had a faulty dim dip due to a stalk before?

 

Any ideas people?

 

You need to check the sidelight and ignition feed to the dim dip relay first.
If these are ok and it(relay) is getting power and earth it is your dim dip relay.
The stalks do play up but you are getting lights on headlight switch setting so is not this.
tabetha

 

Try the brown and white relays at the back of your fusebox on the right. They become corroded over time and a bit of sandpaper should fix it.

(Had the same problem on mine, and was told this on the rsoc. worked perfectly afterwrds. )

 

Cheers!

Had a quick peek at the brown relays and the connections are immaculate!
Will have a poke about with a multimeter later....

 

YES- otherwise I wouldn't have suggested it.

I have experienced this problem - stalk related on:
Mk3 escort RS1600i
MK4 escort RST x2

If you're going to rubbish peoples suggestions and your clearly know enough about the lighting wiring system anyway - what was the point of the post?

 

i know you have said you have checked the relays

but try wiggling them

either 2 little brown or white relays at the back of teh fuse box

which is the main problems

if not then its either stalk or bulbs

 

No need to be so defensive mate!
I didn't rubbish your suggestions... I was merely trying to get more info out of you in the quest of finding out the best way to sort my car.

I'm hardly going to run off and buy a stalk just because you post a single sentance relpy with no explanation to backup the suggestion.

Anyway, what RS1600i ever had a dim dip function?!