I have just fitted a late MGB rev counter to my early late bay, wiring it as per previous threads as follows: Bullet connector - to negative side of coil Terminal next to bullet connector - to ignition switched live Terminal to case - to earth I haven't connected the back lighting as yet Thing is, it doesn't work! I was told that the rev counter was working, although I bought it off ebay so who knows, however I do have accuspark electronic ignition fitted. Is there any way I can test the rev counter & could the electronic ignition be preventing the rev counter from working?
I've got a Lumenition electronic ignition and my rev counter works fine .......but then it is fitted to my MGB
I think part of the problem is that running a 6 metre wire from the coil to the front of the bus carrying the 12volt pulse signal with hundred-volt plus oscillations on it when the points or electronic ignition breaks the circuit is asking for trouble, coupling noise into other wiring going the same way. On an MG where the engine is much closer to the dashboard the problems will not be as bad. One of the reasons my rev counter has a black box in the engine bay, and a serial cable to the display in the front of the bus.
I have a similar rev counter - I think it's the Spitfire one, but they are very similar - and it worked fine with my A/C engine running points, and it runs equally well with my subaru with its EFI.
just found the problem - a break in the wire running from the coil to the rev counter - replaced and now working (subject to being woken up with a little tap on the glass!). Thanks peeps.