Talk Morgan Forums Morgan Sports Cars Maintenance & Servicing Rev counter and now temp gauge

Hello Nick
I have the same on my ARP4. Let you now when we found the problem.

Stefan

Ah well - spare key only worked for those tests. Just went to drive it and same old symptoms but with the spare key. Dash off next then....

Do also test the earths they are often bad. Though I am on the second pcb.

Well pulled apart the dash. No sign of any wiring issues...i had wondered if mice had got in. Checked the earth by the heater box.... cleaned it all up but it was clean anyway. I don't like the concept of all those small wires going into one big terminal though...

Anyway as I have a spare board that I had modified with the meatier flyback diodes, I thought I would just swap it out and see what happens.

Put it all back together and had a run out. Worked this time but I have no faith in this car any more so will reserve judgement. I'm a bit annoyed at having invested in door checks and new tyres as right now I could happily say goodbye to it. There's character and idiosyncrasies in cars, and then there's hassle and pains in the backside that takes away all the fun... I'm in the latter camp just now....

There certainly are a few anomolies in the wiring and electronic setup of the Morgans. I had my share of problems with the circuit board too. Now that I have a completely wired system it does seem to be reliable (thanks to Borghi). Perhaps you could try soldering the wires together or even solder them to the conector. The current is so low that the slightest resistance could cause a problem.

I still have some strange problems with the instruments including resistances that seem to change depending on whether the engine is running or just the ignition on. I will get Borghi to check earth connections the next time it goes in for service. The two that are giving me problems are the fuel gauge (always a mystery on a Morgan anyway) and the temperature guage. At least I seem to have the fuel guage reading about 90° when the engine is at that temperature and the fuel guage showing empty when I have about 30 to 50km of reserve.

Keep in mind that I have changed the dash and have separate instruments so you can't really compare this to the original.



Just go for a nice drive on your favourite bit of road and the enthusiasm will come back

Sorry to hear about your annoying issue Nick and yours Peter. I don’t know if this might help or not but it might be worth making and breaking the Caerbont ‘Multi Function Unit’ connectors a few times. The + 4’s Ford Visteon EEC-V ecu may be sharing instrumentation data with the MFU over the ecu’s J1850 bus before it gets to the dash pcb (do you still have a MFU Peter?). On later + 4’s the MFU is located next to the ecu in the metal enclosure in the engine bay. I think one of Dave's old pics of Bumble shows water staining in the enclosure, not so good if the signal connectors are not environmentally sealed.

Thanks Peter.
Rog... I'll check under the ecu cover and do as you suggest. I did spot the technical issue with that cover when I got the car so whipped it off and used some neoprene to stem the flow of water from the heater box outlet that naturally flowed through the electronics. But it wont ham to take another look under there.

Thanks for the encouragement folks
Nick