The reason for the fuse failure was you no longer (with relay) had enough current to "wet" the HiBeam fuse contacts and they would corrode as they were in the engine compartment.
 
Graeme
 

so it makes sense to me that I need a relay to cover the load of the additional inner driving lights.
 
I had a bit of a peek through the Gregory's escort manual I have here (including rs2000), and found this.
 

 
 What can clearly be seen here is that at some stage (it doesn't seem to specify the year) ford put a factory relay in for the driving lights (point 23).
 
Can anyone verify per chance if they have seen one of these relays in the flesh?.
 
Dave

Dave
 
Funny, I had a '77 escort rally pack from new as well (until someone totalled it) hence the new RS. It did come with the Driving light relay as it had seperate driving lights. Yes the same power draw as the RS but no relay in the RS. I did a lot of night driving those days so it was one thing I was very aware of.
 
Note the description "driving lights" not "Hi Beam" relay.
 
There should be an appendix to this wiring for the RS.
 
I'm not at home this week so I can't check my wiring diagram, so this is from memory but I do remember adding relays to the RS.
 
I must get round to putting up a thread on my escorts....Currently restoring a 79 RS just like my original one.  Monza Red as well..:-) 
 
Graeme

The relay was for the rally pak. If you have too higher wattage lights without relays you will melt the contacts and plastic that holds it all together in the dipper switch. It has been done many times. 

Ossboss
Ok we have now established that rs had no relay, outers were high/lo beam and inners were high beam. And were not sealed beam.
but what wattage globes and what fuse rating did rs come with factory?

Cheers

Outers 55/60 or 50/55  inners 55.  As for fuses probably 20 amp. Most inners were uprated to 100w, check this as this may be adding to Dave's problem. ie faulty dip switch or wiring damage if no relay.  
 
Graeme

There you go Dave, if a 20 amp is factory fit explains why your 16amp 'sometimes' blows.
 
cheers

So is that to say I should be safe with a 20 amp fuse? Or should I be worried about the stalk etc?

Does anyone have any documentation or seen a 20 amp being used in the flesh before I put one of those bad boys in?

Cheers

Dave

I recommend putting a relay in for headlamps regardless, not only to prevent your stalk burning out, but if you use thicker wiring you'll also get brigter light by virtue of lower losses through the wiring itself.  Definitely a good thing for any Escort.
 

speaking to a very knowledgeable chap today, he says there is a relay up under the dash (behind the cluster somewhere), that has something to do with the high beam lights. Can anyone confirm if their car has one or not?. Is this a factory thing?. Im currently at work so not able to check my car.
 
Dave