MEP-002A No Fuel and DC Breaker Popping

[Light in the Dark]

Got an 85 Hollingsworth 002A that Letterkenney got a hold of back in 2007. It has only 7 hours on it now. Was playing around with it for the first time yesterday... fresh fuel and new filters. It appears they disconnected the electric fuel pumps (I believe that's what these are). Images attached.

1.) Do I need to trace these wires back to see which is appropriate for which pump, or are they both energized all the time (but only a return signal is sent to aux pump when tripped by the in-tank float)? Meaning can they be tied to either and function fine, or are they location specific?

2.) The DC breaker pops within a few seconds of turning the unit to Prime + Run. It does this with neither of those wires hooked up, but also with them hooked up each alternate way (testing...). The unit WILL crank if I just run from OFF direct to START.

Also I am not getting any fuel to be pumped anywhere in the system (I am sure this is all related). Nothing into separator or inline filters, and of course nothing into the return line.

Might have been better to tackle these independently, but I'm thinking they are all related. Thanks for your help.

 

[Light in the Dark]

And sorry for the crappy photos... my cell phone camera sucks.

 

[Triple Jim]

In normal run mode, two pumps are plumbed in series, and are both energized. When using an auxiliary tank, the third pump is also constantly energized. The float switch in the built in tank controls a solenoid valve that allows fuel from the aux tank to be pumped into the built in tank. When the solenoid valve closes, the third pump works against the closed valve, but it's made to to this, and it slows down, patiently waiting for the valve to open again.

 

[Light in the Dark]

In normal run mode, two pumps are plumbed in series, and are both energized. When using an auxiliary tank, the third pump is also constantly energized. The float switch in the built in tank controls a solenoid valve that allows fuel from the aux tank to be pumped into the built in tank. When the solenoid valve closes, the third pump works against the closed valve, but it's made to to this, and it slows down, patiently waiting for the valve to open again.

So the three rubber boot leads that go to these... does the wiring matter, or not since as I read this... they are all constantly energized?

 

[R Racing]

I could be wrong but I do believe there is a + and - to the pumps so they do make a difference.

 

[Light in the Dark]

Hopefully these connections are in the book. Time to go do some reading. Thanks

 

[Guyfang]

Yes, look at the schematic. Two of the wires go to the primary and secondary fuel pumps. One to the Aux fuel pump. Find the wire (P62E16) to the Aux fuel pump on the schematic. Hook it up. Then hook up the other two. doesn't matter which is which.

IF the CB-2, D.C. circuit breaker pops, start un hooking first the fuel pumps one at a time, trying to put the S-1 start switch in the prime and run position. If it still pops, then you need to start unhooking things, one at a time. I would start with the K-4, (Aux Fuel Solenoid).

 

[jamawieb]

With the switch in the prime and run position, you will have 2 of the 3 wires with 24 volts. Then when you turn the switch to aux/run, all 3 will have 24 volts. When I'm referring to the wires, I'm talking about the connectors you have pictured, you have one connected and 2 disconnected.
1st thing you need to do is disconnect all the wires, just because the one is connected to the aux pump does not mean its connected properly. Then see if the DC breaker pops with all 3 disconnected.
2nd when you find that the DC breaker stays on with all three disconnected, turn the switch to prime and run, find 1 wire with 24 volts and connect one pump at a time to the 24 volts to see if the breaker pops.
3rd when you find the pump that is the trouble maker, follow the wire towards the pump and you run into a box looking thing mounted to the frame. This box looking thing is the trouble maker, it's a capacitor that is notorious for shorting and causing your problem. You just have to cut the entire box out and splice the wires back together because the capacitor is not needed for civilian use.

Good Luck!

 

[Light in the Dark]

Yes, look at the schematic. Two of the wires go to the primary and secondary fuel pumps. One to the Aux fuel pump. Find the wire (P62E16) to the Aux fuel pump on the schematic. Hook it up. Then hook up the other two. doesn't matter which is which.

IF the CB-2, D.C. circuit breaker pops, start un hooking first the fuel pumps one at a time, trying to put the S-1 start switch in the prime and run position. If it still pops, then you need to start unhooking things, one at a time. I would start with the K-4, (Aux Fuel Solenoid).

So I didn't get back to this today, but it appeared that two of the three electric pumps were vaguely wired 'together' (the two units further back from the operator panel) and the frontmost was by itself. Do you all know which of these are the primary, and which are secondary and aux input? It appears the last two are the aux input, so my assumption is thats also the redundant pump versus primary?

 

[Light in the Dark]

With the switch in the prime and run position, you will have 2 of the 3 wires with 24 volts. Then when you turn the switch to aux/run, all 3 will have 24 volts. When I'm referring to the wires, I'm talking about the connectors you have pictured, you have one connected and 2 disconnected.
1st thing you need to do is disconnect all the wires, just because the one is connected to the aux pump does not mean its connected properly. Then see if the DC breaker pops with all 3 disconnected.
2nd when you find that the DC breaker stays on with all three disconnected, turn the switch to prime and run, find 1 wire with 24 volts and connect one pump at a time to the 24 volts to see if the breaker pops.
3rd when you find the pump that is the trouble maker, follow the wire towards the pump and you run into a box looking thing mounted to the frame. This box looking thing is the trouble maker, it's a capacitor that is notorious for shorting and causing your problem. You just have to cut the entire box out and splice the wires back together because the capacitor is not needed for civilian use.

Good Luck!

Well unhooking the third wire was a good idea... now the DC circuit is not tripping. Progress, albeit small!

What is the proper way to test this? Negative back to the battery post, or are there common spots on the frame which will double duty?

 

[jamawieb]

Negative back on the post. Your problem is going to be with the pump that was still connected. Luckily it looks like its the aux pump so we can work around it for now, leave that one pump disconnected. Turn the switch to prime/run and you will have 2 wires that have 24 volts and those 2 hot line need to be connected to the 2 primary pumps. The 2 primary pumps I'm referring to is 1 primary that is right next to the auxiliary fuel pump and the secondary pump is behind the 2 pumps that are side by side (you have a picture of it in your second picture). After you have the primary and secondary pumps hooked up, let them pumps runs for about 2 minutes or longer to cycle the fuel. Then you should be able to start it.

 

[Chainbreaker]

Do you all know which of these are the primary, and which are secondary and aux input? QUOTE]

The Aux pump is the one with the solenoid on top of it and the input line should be capped off when not hooked up to an aux tank. The other two are both primaries as they are hooked up in series, you can verify that by following the fuel line routing, one fuel pump's output should connect to the other pumps input. Normally both pumps are active, however only one functioning pump is necessary to supply fuel to the injection pump. It can be either one as they don't have an internal check valve due to being hooked in series (the round check valve is midpoint between the last pump's fuel line and injection pump). If one pump fails they are designed to allow fuel pass through the non-function pump to allow the good one to continue to supply fuel to the injection pump (redundancy factor). So...if you hook up both pumps and the breaker trips you can hook up only one of the primaries and if the breaker does not trip it should start. If neither of the primaries causes the breaker to trip you are good to go. By the way, did you pull the bottoms (twist lock) off the pumps and clean the sediment filters?

 

[rustystud]

The usual culprit for the circuit breaker tripping is the fuel pumps built in "suppression" unit. This is on the power line to the pump. By cutting this out of the circuit you will have you pump back usually.

 

[Guyfang]

You know, I don't feel bad about going to a physical Rehab clinic for 3-4 weeks now. You guys got this covered. I will be up in the Alps, and may not have email capabilities. But if I do, I will try and contribute a little bit.

Light in the Dark. Partner, you need to get the books out and crack them hard. This is a easy set to work on. But you got to help yourself.

Good luck and keep up the good work!

 

[rustystud]

You know, I don't feel bad about going to a physical Rehab clinic for 3-4 weeks now. You guys got this covered. I will be up in the Alps, and may not have email capabilities. But if I do, I will try and contribute a little bit.

Light in the Dark. Partner, you need to get the books out and crack them hard. This is a easy set to work on. But you got to help yourself.

Good luck and keep up the good work!

What's all this talk about "rehab" anyway ? Are you getting surgery for something ?

 

[Guyfang]

I got lucky. Found internet at the AFRCS army hotel near my REHAB! I am at at clinic to find out if I am able to return to work, or be sent into early retirement. Been here since Tuesday. Might go home next month, 13th.

 

[Triple Jim]

Guy, like Rustystud, I'm anxious to hear what landed you in rehab!

 

[Guyfang]

It started with my shoulders. Had one operated on. The next will be soon. Then my heart. The heartbeat trigger fires every so often to soon. Got a pill to keep my BP under control. Then my joints. All of them started to hurt. Now the quacks have found something new with my heart. Will find out maybe Tuesday. I spent the week wired up like a robot. The good side of this walking in the Alps! I love it here! Been walking 10 Knicks a day, stationary bike 20 Knicks and lots of swimming. Was here last year, lost 10 kilo's. Put 5 back on, but have lost a few since being here this time. Going to keep them off this time!!!

 

[Triple Jim]

Sorry to hear you're having all these problems! Get better soon, and enjoy the Alps.

 

[Light in the Dark]

Well I haven't had time to circle back around on this one yet, but I did test the three inline receptacles... they should be 24/24/0V, correct? I got 24/24/100mv.

Does this point to a short?