Transfer pump problem

Hogy59 · Post by **Hogy59** » Sun Dec 03, 2017 4:35 pm

Filled up the tips with (relatively) cheap 100LL the other day....and now my left transfer pump is not getting power.....pulled the switch, and I have a good 12V to the switch, and voltage coming out of the switch...I tried swapping switches with the other tank..no help...

I see a resistor (I think) in the line coming out of the back of the switch...anyone had any issues with these?

Any ideas? I hate chasing shorts.......I unhooked the disconnect at the wing connection, and I don't think I'm getting power that far....

ajak · Post by **ajak** » Sun Dec 03, 2017 7:36 pm

Do you have access to a clamp-on ammeter (has a "clamp" that you put over one of the wires to check for current, without having to disconnect anything). High current = shorted. No current = open circuit downstream, or a bad pump.

Other thing to try is measuring voltage right at the aux pump terminals. Good voltage + pump not running = bad pump. No voltage = problem somewhere in between.

Or maybe you still just have the notorious "cheap fuel" detection circuit installed.

Good luck...

Hogy59 · Post by **Hogy59** » Mon Dec 04, 2017 6:13 am

The pump is good...I hooked it to a battery charger to empty the tank and it works fine...the CB is in, so I don't have a direct short. I'm down to chasing a loose wire behind the instrument panel....Oh joy!!!!

DeltaRomeo · Post by **DeltaRomeo** » Mon Dec 04, 2017 6:31 am

I suspect the "resistor" item is actually a diode to prevent feedback. They do go bad (just replaced one in a pump circuit for a sawmill). Try testing downstream of the diode to verify power beyond it going to the pump.

Kirk · Post by **Kirk** » Mon Dec 04, 2017 9:22 am

Another point to check, I believe, is the connectors at the wing root. Check the parts CD for a diagram or pull back the headliner near the forward door pillar.

The wiring diagram lists color coding for factory wiring, some connectors I've found have a number written on them that correspond to wiring diagram or parts diagram.

Bear in mind that intermittent pump failure to run is not unheard of. It's possible the pump will work if reconnected and you have an intermittent problem.

Kirk

Hogy59 · Post by **Hogy59** » Mon Dec 04, 2017 12:04 pm

After more inspecting, I finally found it....the wire hooking to the switch feeding the pump had broke into inside the slide on fitting...it was still hanging together but had no continuity....

It is the little things that cause the biggest problems.......

Chris in Milwaukee · Post by **Chris in Milwaukee** » Mon Dec 04, 2017 2:04 pm

Thankfully that little thing was an easy repair!

Hogy59 · Post by **Hogy59** » Mon Dec 04, 2017 5:45 pm

Transfer pump problem

Transfer pump problem

Who is online