VintageMopar wrote:
A word about electric fuel pump wiring. Keep in mind you don’t want a ignition on fuel pump running gas on you while your rig is upside down in a ditch. GM used an oil pressure sending unit in the early days so if motor was not running it would shut off. (Vega) . Chrysler used an asd relay that was pcm controlled as did ford . Have to think a bit about how to control on non computer engine. Maybe alternator triggered control relay on 13-14 volts?
Yes, absolutely. That's why I specified a momentary, spring-loaded switch for the 'primer' bypass.
For a while, manufacturers were installing inertial 'crash' switches that would turn off the fuel pump. However, there was a tremendous amount of 'false positive' triggering -- many times the number of actual crashes.
I've been trying to figure out a good way of having the fuel pump only running when the engine is running. (Eric is going to need a manual cut-off switch for when he's running on propane.)
My problem is K.I.S.S. but reliable. Everything I've come up with so far involves complex circuits, too many components, too much expense, electronics, and so forth.
Oil pressure sensing still seems to be the best ... old school but that's often the best. There's a way to set up your motorhome for both gauge and indicator (aka 'idiot') light. Leeann's done it to her motorhome. We could 'tee' off the indicator light circuit but the there's a time lag between engine start and sufficient oil pressure.
If I come up with something simple, inexpensive, and reliable, I'll try to remember to let everybody known.
In the meanwhile, everybody should remember to turn off the ignition (key) switch if you're involved in an accident.
