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Old 02-02-21, 09:41 AM
PEU186F PEU186F is offline
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Quote:
Originally Posted by peter dowdle View Post

The fuel gauge in my 412 sat on empty. Replacing the tank sender solved the problem.
Peter, et al

The 411 wiring diagrams on this site show that there was a step change in wiring and fusing practises after the 410, fusing in particular was vastly improved. They also show that the fuel and temperature gauges were fed by the voltage stabiliser which is required by the gauges that incorporated a heated bimetallic strip, that were the standard by this time. These will show empty if the tank sender or wiring fails to open circuit. This type of gauge characteristically takes a little time to react when you turn the ignition on but does have the advantage that it doesn’t waver about as the fuel sloshes about in the tank.

The gauge used in the 410 and earlier cars , which relies on opposing electromagnets, doesn’t require voltage regulation, does react instantly when one turns the ignition on and does waver about as the fuel moves about and also fails to (beyond) full if the tank sender or its wiring go open circuit.

Note that the tank senders have to have different characteristics to operate the two different types of gauge correctly, one shouldn’t change one without changing the other.

I trust this clarification may be a help to somebody someday

Roger
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