Headlamp relay

[Andy8421]

Andy,

You mentioned these connectors as gas tight, why is this necessary?

Richard Hawkins

Richard,

The killer of a decent contact is corrosion. Ideally you want to have a contact design that places sufficient pressure on the contact area to exclude moisture and oxygen to avoid the contact corroding - hence 'gas tight'. In the case of a switch where the contacts will be separated as part of the design (when the switch is open), then a sealed case and 'wiping' action of the contacts helps to keep the contacts clean.

In a car, particularly in the engine bay where water can be a problem, sealed connectors along with adequate contact pressures are the way to go.

Some examples of what not to do on the Elan are bullet connectors that have low contact pressure, no sealing and almost seem to be designed to collect water and allow moisture to leach along the contact area, that dreadful open frame immobiliser switch in the glovebox, and the switches that the manual laughingly calls 'microswitches' that control the headlight relays that are repurposed door pillar courtesy light switches.

Good connector design is a subtle art, but has pretty much been solved in modern car design. As I mentioned above, the Elan could be made 'bullet proof' at the expense of originality by using modern connectors and a more robust and safer circuit design.

[RichardHawkins]

Andy,

Thanks for the explanation, there have been times when I questioned the wisdom of what I have done, especially when friends encouraged me to just buy a new loom to the old spec. I have made errors along the way, but am now glad I stuck to my plan and updated the wiring. Most of my improvement work has been kept out of site so the car still looks as it should.

Richard Hawkins

[gus]

If you have a LHD car, it is incredibly difficult to get places in the UK to understand that there is a difference.

Yes the Lucas connectors are junk, sorry, that is what it is.
I rewired my car with pretty generic Molex connectors in 1995, at that time a 25 year old car, and have had virtually zero connector related issues since. The corners[parking/indicator/headlamps] i used gold plated connectors, because when wiring one car, the difference between 50 cent terminals and 10 cent terminal is unimportant.

i think the stuff coming out of the UK now is pretty good quality, and if I was ordering a harness for a LHD car from the UK, I would confirm that there is a LHD harness and a RHD harness and that they know the difference and are sending you one so marked.

THat said, I am not so sure that Lotus used a different harness as all the wires kind of shot through the firewall in the general direction of the dash in a big tangle.