Hi Dave

I know nothing about your Morgan car models but assuming they are OBD2 compliant and they very probably are, then there are very cheap (about £15) OBD2 fault readers available on the internet. If all you requite is to read the fault codes when the engine warning light comes on and then reset them and put the light out they would be do the job. They plug into the diagnostic socket. Just type obd fault reader into google

Forgive me if you already know this but an example of a fault code these devices would show is P0301 which means misfire on cylinder 1. You can look up all the code meanings on the internet.

I have had one of these for years and it works very well on both my Ford cars and on my wife's Smart car (heaven help us) which is made by Mercedes. Ironically it does not work on my 1999 Morgan because it is not OBD compliant despite the fact that pretty much all cars made in that year were. I have a much deeper diagnostic software tool on my computer for the Morgan.

If you require a deeper look into the car workings then Simon and Hamwich posts are more suitable.

Regards Tony