Talk Morgan Forums Morgan Sports Cars Maintenance & Servicing Headlamp issue 97 +8

Hi I’m a new member I bought my green +8 last December it’s a 97 3.9 , I have an issue with the headlights off side works fine near side main beam only I’ve checked the fuses Under the dash and the bulb is there a relay or fuse elsewhere. I’m an absolute duffer when it comes to electrics

With neither high or dip beam operational it may well be the earth that is causing your issue, which is not unusual as connections can corrode over time. The earth wire is usually black and ultimately connects to the chassis as a return to the negative side of the battery, thus without a good earth the circuit can be broken. It might be a good idea to check that out first then come back if nothing found..?

Good luck.

There are no relays involved. Suggest checking the n/'s dipped beam fuse again, it's the one with blue/pink cable feeding bulb . Remove, check for contunuity electrically, clean contacts including holder and replace. Would normally suggest checking ground/chassis connection as well but that is shared with main beam, both of which you say are working fine.

Above assumes you have thoroughly checked bulb filament is OK with multimeter. If still no luck trace power supply looking for +12 volts with multimeter against ground with headlamps on dip and from battery side of fuse box (blue/red cable) onwards.

Hi Richard thanks for your reply I put a new bulb in which is annoying because it looks like there was nothing wrong with the one I binned I just assumed it was the bulb , I’ll try your suggestion on the weekend

Nine times out of ten , poor electrical performance on Morgans is down to a bad earth, but both bulbs share a common earth so this is unlikely to be the cause.

There is no relay on the headlight circuits , but fitting one is really good idea, it protects the circuit and gives much better voltage at the bulb. I think there is a fitting and circuit guide on here somewhere.

If Richards ideas don't bear fruit (or light?) come back here and we will try to come up with other ideas.

Will do and thanks . Electrics aren’t my strong point but I did fit a new Mulfab radiator and it’s made such a difference to the running temp which is now a constant , when I removed the thermostat housing To put the new one in there was no thermostat in there ? Not a good idea ,anyway I digress . It’s good to talk Morgan enthusiasts it’s the same as when I had my TVR

Hi Richard. Ok I’ve cleaned the earth connection the one bolted to the chassis behind the off side front wheel , moved the fuse box so I can see the wires and replaced the fuse and put a news bulb in and still only have main beam on the near side, off side is fine . I’m stumped

Sorry to hear your issue persists. Not surprised checking earth made no difference though as it's shared with main beam, which works.

You now need a multimeter set to measure DC voltage. With dipped beam selected check at fuse box on battery feed side of dipped n/s fuse between there and ground referenced by the colour codes mentioned above. Then if +12 volts or so measured, continue on electrical path towards headlamp on other side of fuse, measuring similarly. At some point you will find the culprit be it bad connection/connector or hidden break in wiring. It could even be faulty contact/break on headlamp plug itself.

I did have a 1997+4 so this may help or not
The wires from the head lamp unit go back inside the engine bay where they connect into the loom using bullet connectors. These are prone to problems from water ingress / rust, so take apart clear and reassemble. If you have wing top side lights then you are likely to find one unconnected bullet (thin red wire) which is the side light bulb in the head lamp reflector.

These photos are offside but I expect there will be something similar nearside.



Good luck.

One area to check is the wiring under the wing. It is a VERY exposed area. Spray from the wheels when driving in the wet coats everything. Morgan used bullet connectors to connect the wiring and these are poor for keeping water out so you get corrosion in them. Mine (2002car) were solid, couldn’t split them when checking for a similar problem to yours. I cut the wires and rejoined with spade connectors, finally sealed the joints with shrink wrap. That cured the problem for me.
Gomog website has wiring diagrams but they are a guide only! Morgan had a habit of changing things so the wire colour codes could be different!
www.gomog.com