I found the problem and I have fuel pressure again

[D_E_Bishop]

I have made several posts recently regarding my in-tank fuel pump not running and losing power due to lack of fuel. Well I finally found the problem only to the component level, but, it has been corrected.

I became so consumed with finding and tracing the wires involved with the fuel pump that I stopped looking for the problem in a logical way. I spent a long sleepless night trying to sort things out in my mind and there it was, K.I.S.S.. Iwent to the storage yard the next day and applied power to the pump using a jumper and so on and so forth. Tracing each of the five wires not visually but functionally.

I even went so far as to hook up a simple SPDT relay to the five wire connector. Everything worked. The only thing I lost with the change of relays was the five second prime timer.

I spent some time searching the web for others who had the same problem and found a 2003 post here on RV.net about the same problem and that members solution. I also found a similar post on IRV2.net.

I don't know what is wrong with the original relay or the replacement relay I bought but bot the 25 year old relay and the brand new relay didn't work. It maybe the relays or it may have been the connector but both are gone now and I can once again stomp on the pedal and run up hills without the engine starving out for lack of fuel pressure.

The replacement relay came with a new socket and the wiring matched or exceeded the original wires. The wiring, is therefore, essentially the same and the original fuses, there are two in the circuit, are still there. Sometimes we senior members have a hard time seeing the display of our DMMs or our test lights while tracing circuits. I bought a piezzio siren for a couple of bucks and when working on long circuits or when you can't really see the meter or test light, that 107 db piezio can be heard.

So thank all of you, including the OP from 2003 and those who offered me help for today.

[j-d]

By the Grace of GOD We Go!

It's a "Bosch" or apparently TYCO type. Good form factor/socket choice, the things are available everywhere.

[D_E_Bishop]

Thank you Mr. Wizard and all involved with RV.net and the search engine. That post from '02 helped.

j-d, The relay is a Gryphon YL-314-c-12vdc, it is about a one inch cube, SP/DT with the connections labeled 85&86 for the coil, 30 for the mover and 87&87a for the stationaries. RELAY This link shows several relays, I used the 40/30 amp model in the middle. I bought it from my almost local electronics store. The socket wiring is pretty universal as far as the wiring color code. I like having two or three in the shop along with several fuse holders from 3.5 to 30 amp ratings. I do carry spares in the MoHo but even more in the shop.

It is a common relay used for automotive accessories and sold buy Pep Boys, AutoZone, NAPA and on and on. I used one to parallel my Bad Boy horn rather than just replacing the OEM. I am also going to install the fuel pressure gauge and as you suggested a pushbutton switch for the prime circuit.

In California it was required to have a bypass return built into the mechanical pump as well as GM putting an in-tank pump in. The mechanical pump will handle starting as it has a higher output than the pumps used in the other 49 states but the pushbutton is a option and as Mr. Wizz says, Options, Always have options, and the Lord knows I want the journey to go much smoother. I ask for that a lot.

[j-d]

Now you're talkin'! Find out where the power starts, where it needs to be and what it needs to do when it gets there. Then make a new connection. I ran into an auto electric specialist who told me exactly that. We often can't find the exact spot where a wiring harness is open, shorted, or grounded but we CAN bypass and get the system working.
What kind of relay did you get? It's pretty critical, so you may want to carry a spare.
Just add a push button switch and some wiring to serve as your primer.
Good on You! Well Done!

[MrWizard]

Glad to hear you got it fixed, and the explanation