Wiring for LP pumps?

[Peter Olliviere]

My qustion concerns how the LP pumps are actually switched on or off. Looking at the RF Electrical Manual I see the following wire discriptions,

LH Pump wire is Black/Green
RH Pump wire is Black/White
2 Way Valve is Black/Orange
Crossover Switch is Red/Green + Black/Orange

The 2 Way Valve is a power on power off type valve that fuel flow is directed to either side when power is applied. I assume that the Red/Green is power on the switch and the Black/Orange when switched takes that power to the 2 Way Valve.

My question is how are the LP pumps actually switched? It looks to me that when you flip the selector switch you power the valve but I don't see the connection to direct which pump to operate.

The reason I am looking for this information is that I am using a 6 way valve that has inputs and returns for each tank and the surge tank built into it. the valve is motorized and works by changing which lead is powered. The change over switch is a on/on switch that changes the polority on the valve thus changing the feed and which pump is powered. What I am trying to work out is if the pumps on the original RF setup are actually being turned on and off in some manner and not by the switch alone.

Thanks Peter

[Dan Weilacher]

Hi Peter, from looking at my setup I am going to have to make a jumper from my low pressure pump to the "anti-back flow " valves as I do not believe the RF harness has had them incorperated. I'm not that far along as you , sorry . [img]/ubbthreads/images/graemlins/tongue.gif[/img]

[Peter Olliviere]

Dan,

when I first started to review the fuel system I noted that the way it was shown could lead to a backflow concern between the pumps. That was one of the reasons I decided to go with a valve that provided discret paths from tanks to LP pumps thus avoding the backflow concern. I was very surprised when you posted your "whats this part?" question that turned out to be oneway valves to address the problem.

In thinking about it you do have the same question I do, and that is do you take your power from the pumps and assume that when the pump either LH or HR is enegized you will enegize the backflow valve for that pump, or do you jump from the changeover switch? A schematic of how the pumps are actually wired would clear this question up but unless I missed something This diagram is not included in the manual.

Peter

[Jim Dewar]

Good Morning Peter,
I spoke with RF recently about that area and Robert said the solenoid is closed with power off so a jumper wire from pump to solenoid is correct.

[Dan Weilacher]

What Jim said, haha [img]/ubbthreads/images/graemlins/grin.gif[/img] Thanks Jim .I'm guessing on this one but I bet the lead that attaches to the three way valve is in circuit with one of the pumps as well. I would guess the right Low pressure pump. Due to the stock three way valve either being energized or not, so you need to make sure your in "sinc" with either tank and dont accidently return fuel back to the wrong tank. If this is the case an ohm meter may show it is linked to the pump. That way you can run the correct outlet hose to the corresponding tank. I think I made sense , something to try anyway. [img]/ubbthreads/images/graemlins/crazy.gif[/img]

[Peter Olliviere]

I'm back, I't amazing how work somtimes intrudes on what important [img]/ubbthreads/images/graemlins/smile.gif[/img]. Anyway Dan you more than likely are right that one of the pumps is inline with the valve, as I think about it that makes sense. In your case a jumper over to the pump that is not on would take care of things, I think [img]/ubbthreads/images/graemlins/confused.gif[/img]. As for my problem I still have to understand within the relay box how the two pumps are switched. Need I mention that electrical work is not my strong point.

Peter