Talk Morgan Forums Morgan Sports Cars Maintenance & Servicing Headlight issue

The "vice versa" part of your wiring description worries me Dave. I know you need to sort missing main beam but would re-engineer spotlights with a relay in the course of fixing this (possibly blown fuse or headlamp dipswitch issue)

The relay coil (trigger) should receive power from headlamp main beam via the spotlight rocker switch. The main relay contacts should receive power from an extra fused power feed. The borrowed wiring diagram below illustrates this. The spotlight rocker switch could be fitted in series with orange cable or better still in the green coil ground lead from contact 85.



Wired this way the headlamp dip switch will not have the extra spotlight current through its contacts, neither will the rocker switch. The spotlights will only illuminate when switched on and headlamp main beam selected. You then won't get the undesirable and potentially dangerous vice versa effect.

That does point to either a problem with the main beam relays/wiring or the main beam contacts on the the actual column switch itself. Good luck the investigation work.

Typically there aren't any relays for dip/main headlamp control. The only Morgan I'm aware of that does use one is the 5 speed V twin M3W. I know some have added them to save the dip/main light switch contacts but it's designed to cope so unnecessary extra complexity in my view.

Using a relay for spotlamps is advisable though, however if the car used LED's all round you could easily get away without.

In a previous post Dave said he was sure he'd fitted relays when wiring in the spots. I blew my stalk switch when I originally replaced my sealed beam headlghts with halogen H4 units (no spotlights). I had to replace the switch and fitted main and dip relays.

True for more recent models but the older stuff had sealed-beam headlamps at something like 35W. Bunging in a pair of 55/60W halogens leads to quite an increase in current through the dipswitch which will burn them out if relays are not fitted. I learned this the hard way.

Gents

Nothing like a good topic to get people thinking. I always find electrics a 'Dark Art'. It will be interesting to find the cause. I will update when i get to a solution.

In the mean time thank you for your suggestions. Just to let you all know I have put in LED for Side, Indicators and rear brake lights.

Gents, just an update. The problem i had was caused my one of the wires leading to the relay coming away from the female fixture. Next problem, sorting out my LED indicators!

Good news!

What's wrong with the indicators? Are they fast flashing? If so, need an electronic flasher unit - easy replace, just make sure you get like for like (2 or 3 pin usually)

TBM
Sometimes they work, sometimes not. My bet is on a faulty connector.

Is it side specific or affects both sides?

When the stalk switch fails do the Hazards still work?

The feed for the indicators goes through the Hazard light switch - often, due to lack of use, the feed through the switch fails. Next time the indicators work, give the Hazard Switch a few clicks on and off and see what happens.