Electric fuel lift pump on Nanni 3.21

[Grant Gordon]

I have just pulled my ancient Universal diesel and installed a Nanni 3.21. The Universal had a bulkhead mounted electric lift pump and I would like to keep using it with the new engine. It make bleeding easier should it need to be done.

I am having trouble finding an electrical connection that is "hot" when the key is turned on. Ideally I'd like to do this without splicing into the existing wiring harness. Has anybody dealt with this before and if so, where did you make the connection.

Thanks

Grant

[DeepFrz]

Was the electrical lift pump set up so that it only ran to bleed the system? That is how it should be unless you bypass the mechanical lift pump on the engine.

[model 10]

The same source as the alrernator field. An electric pump uses almost no power.

[Blue Stocking]

Originally Posted by Guy

The same source as the alrernator field. An electric pump uses almost no power.

I think the Nanni switches field current on thru a relay, does it not ? You could tee off the oil pressure sender location with a normally closed switch, which would run the pump when your engine is running, and with a SPDT remote switch to a + feed for bleeding purposes. Kill 2 birds without cutting into the harness.

[model 10]

Originally Posted by Blue Stocking

I think the Nanni switches field current on thru a relay, does it not ? You could tee off the oil pressure sender location with a normally closed switch, which would run the pump when your engine is running, and with a SPDT remote switch to a + feed for bleeding purposes. Kill 2 birds without cutting into the harness.

You should "not" mix warning or indicator circuits with electric motors, or anything else for that mater. A warning circuit should be on it's own.

[a64pilot]

Besides most low oil pressure switches work by switching ground not power.
Backside of the ignition switch I bet has a contact that is switched power.

[Grant Gordon]

The Nanni does not have anything on the alternator that is "hot" when the key turns on. Only after the engine is started. In reply to the comment about bypassing the mechanical pump, the manufacturers documentation clearly shows that an electric pump can be used inline with the mechanical one. It just doesn't offer a suggestion for power. For the present time I am going to go without it.

[model 10]

I have never heard of a start switch that did not have an accessory term. Usually the term is used to power up the alternator field at the regulator not the alternator itself. You would NOT want to use the actual field power itself. It's only about 5 vdc max and you might totally freak out the regulator.