Talk Morgan Forums Morgan Sports Cars Maintenance & Servicing Still confused...Fuel Pump voltage (2002 4/4)

I am still very confused.

After some issues with no starts and suspect Fuel Pump Relay (see earlier thread) I have now got car starting but the voltage at the fuel pump and the inertia switch is still 7.35v. How can this be? Does anyone have a wiring diagram as the ones we have all shared show the cables disappearing into the 'Engine Loom' and I cannot see the wiring from to the inertia switch and pump.

OMEX suggests that there should be 12v??

This is driving me crazy...

What resistance measurements are you getting across the cables from one connection to another?

Ie if you have a corroding wire it'll have a high resistance and drop volts.

Hello Keith
I had the same voltage problem and contact spray ( Multi Super 5) on the connections took away the problem,.......afther some recherche. Check also negative connection.



Stefan

Could be an earthing problem..Check the engine block earth strap.

Hi Keith. Did you record 7.35v with the motor connected or disconnected? I wonder whether you have a slow pump with high resistance owing to a dirty/tarnished commutator on the DC motor. Can you take the pump out and run it on the bench? If you do manage to run it you stand a chance of self-cleaning the commutator. Just a thought.

With pump connected. I ended up pulling the fuse box holder off to check which fuse was what and then found fuse were not as indicated on diagram (why am I not surprised!). After much faffing around I tried it again and all good! I suspect the wire loom as it drops down to the engine bay near the battery as it was very tight against the footwell. I have relieved some strain and placed neoprene under it.