A request for assistance with Fuel transfer valve, switch, and fuel gauge

[Donald Bartlett]

Greetings all, I hope this post finds each of you and yours well and healthy.

I placed this post here in this category as the work I am doing is with things that are of a retrofit nature. I apologize in advance, if I erred.

I have a 1975 Chevy K20 Cheyenne that I just put two new fuel tanks, sending units, AC Delco/Pollak 6 port transfer valve W/ pigtail, and a new DPDT "On-Off-On" switch for the dash.

Long story short, I am getting my proverbial ass handed to me. I am nearly to the point of having a "54 year old, screaming, pound my fists on the floor, arch my back in reverse temper tantrum". All of you that are parents will certainly be able to visualize this!!!

I have been searching around through threads on this site and others, but am not finding the information I need to get things working.

History:
- OEM single wire solenoid valve went kapooey.
- Fuel gauge worked previously for both tanks.
- Got all the parts
- Installed transfer valve, all new fuel hoses
- Ran brand new brown wires from the DPDT switch down to the transfer valve 213 pigtail. (holes "D" & "E")
- Connected main tank sending unit wire to hole/wire "A" on 213 pigtail
- Connected Aux. tank sending unit wire to hole/wire "C" on 213 pigtail
- (Attempted) to connect Tan wire on passenger side frame rail to hole/wire "B" on 213 pigtail
- Both new sending units are grounded to frame
- DPDT switch wired according to directions

Please take a look at the included diagram / explanation of what I did, what I "think" I know, or have learned, and the info I have been referring to.

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Currently, I am at a point where the fuel gauge will read empty on both tanks, although I have put 10 gallons of fuel into the drivers side tank.

I am under the impression that if this occurs it is typically due to a break in the sender wiring somewhere.

Other research I have done tells me that GM really pulled a whammy when they wired these dual tank units up in that the wiring went down one frame rail to one tank, then tied into the wiring for the other tank, and then went back up the opposite frame rail and into the dash cluster. I assume this is why I have tan wires not only on pin 18, but jumpered across to pin 7 as well.

For the switched power for the DPDT toggle switch, I used the OEM wires from the OEM switch. Pink is my hot, Blue is my ground. Each of these is jumpered across diagonally per the instructions.

I have fond that I have 12 volts to one of my brown wires in the 213 pigtail when the key is on, then when I switch the toggle, I get power to both brown wires.

I cannot, however, say with any certainty that the transfer valve is actually - physically- working.

Is there a way to either remove all of the factory tan wires that have to do with pins 18 & 7 and wire it all new, or can I tie into it somehow knowing that was not what was intended originally?

As for the directions that I have been referring to here they are, at least one version of them!

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Although I have shown and discussed a bunch of electrical stuff here to include some diagrams, electrical is NOT my forte'. LOL

I consider myself to be an excellent mechanic, but the "Sparky-Sparky" stuff really throws me for a loop sometimes. !!!!!!

Assistance with this issue would be so VERY appreciated as I would really like to get the old girl back in action!!!!

BTW: here is the old gurl:

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Once again, thanks a million for any help Y"all can offer to me here.

Respectfully,

Don Bartlett

 

[Old77]

I recently went through restoring the dual tanks in my dually. I fought that thing tooth and nail. I had a couple of issues that turned out to be minor with easy solutions but one of them was incorrect reading of the tank levels. At one point it read empty, at one point it read way over full, blah, blah, blah......

Long story short, the resolution of my issue with regard to that making sure I had good grounds (switch and both sending units) and good connection into the valve assembly and a good connection at the switch on the dash.

BEAUTIFUL truck by the way. Dadgum she's purty.

 

[mcarlo86]

Greetings all, I hope this post finds each of you and yours well and healthy.

I placed this post here in this category as the work I am doing is with things that are of a retrofit nature. I apologize in advance, if I erred.

I have a 1975 Chevy K20 Cheyenne that I just put two new fuel tanks, sending units, AC Delco/Pollak 6 port transfer valve W/ pigtail, and a new DPDT "On-Off-On" switch for the dash.

Long story short, I am getting my proverbial ass handed to me. I am nearly to the point of having a "54 year old, screaming, pound my fists on the floor, arch my back in reverse temper tantrum". All of you that are parents will certainly be able to visualize this!!!

I have been searching around through threads on this site and others, but am not finding the information I need to get things working.

History:
- OEM single wire solenoid valve went kapooey.
- Fuel gauge worked previously for both tanks.
- Got all the parts
- Installed transfer valve, all new fuel hoses
- Ran brand new brown wires from the DPDT switch down to the transfer valve 213 pigtail. (holes "D" & "E")
- Connected main tank sending unit wire to hole/wire "A" on 213 pigtail
- Connected Aux. tank sending unit wire to hole/wire "C" on 213 pigtail
- (Attempted) to connect Tan wire on passenger side frame rail to hole/wire "B" on 213 pigtail
- Both new sending units are grounded to frame
- DPDT switch wired according to directions

Please take a look at the included diagram / explanation of what I did, what I "think" I know, or have learned, and the info I have been referring to.

You must be registered for see images attach

Currently, I am at a point where the fuel gauge will read empty on both tanks, although I have put 10 gallons of fuel into the drivers side tank.

I am under the impression that if this occurs it is typically due to a break in the sender wiring somewhere.

Other research I have done tells me that GM really pulled a whammy when they wired these dual tank units up in that the wiring went down one frame rail to one tank, then tied into the wiring for the other tank, and then went back up the opposite frame rail and into the dash cluster. I assume this is why I have tan wires not only on pin 18, but jumpered across to pin 7 as well.

For the switched power for the DPDT toggle switch, I used the OEM wires from the OEM switch. Pink is my hot, Blue is my ground. Each of these is jumpered across diagonally per the instructions.

I have fond that I have 12 volts to one of my brown wires in the 213 pigtail when the key is on, then when I switch the toggle, I get power to both brown wires.

I cannot, however, say with any certainty that the transfer valve is actually - physically- working.

Is there a way to either remove all of the factory tan wires that have to do with pins 18 & 7 and wire it all new, or can I tie into it somehow knowing that was not what was intended originally?

As for the directions that I have been referring to here they are, at least one version of them!

You must be registered for see images attach

Although I have shown and discussed a bunch of electrical stuff here to include some diagrams, electrical is NOT my forte'. LOL

I consider myself to be an excellent mechanic, but the "Sparky-Sparky" stuff really throws me for a loop sometimes. !!!!!!

Assistance with this issue would be so VERY appreciated as I would really like to get the old girl back in action!!!!

BTW: here is the old gurl:

You must be registered for see images attach

Once again, thanks a million for any help Y"all can offer to me here.

Respectfully,

Don Bartlett

That is sweet! I love the black accents. My Dad's '77 is also having dual tank switch/valve/guage issues and we haven't been able to get it straightened out yet either.

 

[Old77]

That is sweet! I love the black accents. My Dad's '77 is also having dual tank switch/valve/guage issues and we haven't been able to get it straightened out yet either.

What are your issues?

 

[Donald Bartlett]

Thanks a bunch for the compliments fella's,

The issue I am having is no reading on the fuel gauge.

I get a needle that sits at empty no matter the toggle position.

I believe what I am looking for as a resolution is for away to just bypass the factory sending unit and fuel gauge wiring and just run new stuff. I have it stuck in my head that I could just run a new wire to pin 18 on my cluster plug?

The funny thing is this: Because I am not really quite sure what exactly is wrong, I'm not really sure what I'm looking for!!! LOL.

 

[Donald Bartlett]

mcarlo86 said:


That is sweet! I love the black accents. My Dad's '77 is also having dual tank switch/valve/guage issues and we haven't been able to get it straightened out yet either.

Apparently, I am in good company and not alone. LOL.

 

[Old77]

Thanks a bunch for the compliments fella's,

The issue I am having is no reading on the fuel gauge.

I get a needle that sits at empty no matter the toggle position.

I believe what I am looking for as a resolution is for away to just bypass the factory sending unit and fuel gauge wiring and just run new stuff. I have it stuck in my head that I could just run a new wire to pin 18 on my cluster plug?

The funny thing is this: Because I am not really quite sure what exactly is wrong, I'm not really sure what I'm looking for!!! LOL.

You could certainly do that. I don't see what would stop you from running a new wire(s). Since it's not reading on either sending unit there's a strong chance that the issue is somewhere between the switch and the valve assembly, obviously. I'd start by double checking grounds first (valve assembly gets ground by being mounted to the frame) at the valve assembly and the sending units. Once those are determined to be good then start planning out a rewire approach if you're 100% certain that both the switch and valve assembly are in good working order.

Just my $.02

 

[SirRobyn0]

Thanks a bunch for the compliments fella's,

The issue I am having is no reading on the fuel gauge.

I get a needle that sits at empty no matter the toggle position.

I believe what I am looking for as a resolution is for away to just bypass the factory sending unit and fuel gauge wiring and just run new stuff. I have it stuck in my head that I could just run a new wire to pin 18 on my cluster plug?

The funny thing is this: Because I am not really quite sure what exactly is wrong, I'm not really sure what I'm looking for!!! LOL.

Before you do that you owe it to yourself to check grounds. Also as a point of interest and I'm sure you know this already in the original setup the switch on the dash also changed the fuel gauge readings. In the new Pollak system the gauge is handled by the valve on the fuel rail. It is imperative that the grounds are good particularly back at the fuel tank. I'm going to attach a different wiring diagram for the pollak system that might be easier to read. It's the I use when installing one either a fresh install or a retro-fit.

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[Donald Bartlett]

Thank you both (all) for the inputs.

I have been checking grounds as follows:

-Verified that the OEM blue wire ground is good by turning on the key and putting a test light to the OEM hot wire and the blue wire- I get light = good ground.
-New ground wires attached to the two new sending units are securely bolted to the frame (new ring terminals, looks like good metal contact with bolts)
-Ground pin on the fuel gauge cluster/printed circuit sheet appears good- applied 12v hot to positive side and got small spark when manually grounding to the neg. pin.

Have not tried any of this with the new switch attached to dash metal- Possible it needs to be grounded by way of contact and secured with the thing nut that holds it on?

Here are few things I have been looking at:

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Here you can clearly see pin 18 with the Tan fuel gauge wire.

Is there any reason why I could not simply attach a fresh wire from there down to the 213 pigtail (for the fuel gauge) and go from there?

I believe the transfer of tank information takes place at the new valve now, correct??

here is what I am possibly thinking about. Do you all see any flaws with this idea? Am I missing something, possibly obvious?

You must be registered for see images attach

 

[Donald Bartlett]

Would not this new set up allow for the new valve to do what the old wiring did as far as switching tank signals to read each ones' level?

I appreciate you guys.

 

[WP29P4A]

Instead of playing with grounds and hoping they are good, do a simple test. Make a test lead that is 10' long, put alligator clips on both ends. Clip one end to the negative battery cable, clip the other end to your alleged ground and if things start working, you have a ground issue. You can do the same type of test on the positive side. Once you have verified your ground, use the test lead to go from battery positive terminal to where power is supposed to be for the fuel system. Once you find the combo that works it should be obvious which wire you had to bypass to power up the system.

The point is to use temp wiring to correct the issue so you know what needs to be repaired to make it work with the original wiring, don't waste time running wires until you identify the problem.

What worked BEFORE you started adding the new tanks?

 

[Donald Bartlett]

Instead of playing with grounds and hoping they are good, do a simple test. Make a test lead that is 10' long, put alligator clips on both ends. Clip one end to the negative battery cable, clip the other end to your alleged ground and if things start working, you have a ground issue. You can do the same type of test on the positive side. Once you have verified your ground, use the test lead to go from battery positive terminal to where power is supposed to be for the fuel system. Once you find the combo that works it should be obvious which wire you had to bypass to power up the system.

The point is to use temp wiring to correct the issue so you know what needs to be repaired to make it work with the original wiring, don't waste time running wires until you identify the problem.

What worked BEFORE you started adding the new tanks?

Thanks for the advice;

Basically everything. I am pretty certain I am the reason that is does not work now wiring-wise. BUT I only did this as it was what the instructions called for when I wired in the new valve and 213 pigtail.

I am, at this point considering just going this route and calling all of it new:

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The other option may to get a factory instrument bezel and fill it with Phantom series gauges:

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Thoughts???

Not sure which route I want to go yet...............

I appreciate all of you and the time each of you has taken to help me out.

 

[WP29P4A]

I would figure out the gas gauge issue before compounding the problem with more wiring. My suggestion about making up a test wire also works for testing the sender/gauge. Attach a test wire from one of the senders to the gauge and see what results you get, switch it to the other sender and compare what you get. Use the test wires to try out your idea of running a new wire to replace the tan wire. There is a good amount of wiring to do a gauge/cluster install. High level of patience involved and way more time consuming than you would think. Thankfully you won't have to interface them with a ECM. Or two. LOL

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[SirRobyn0]

@Donald Bartlett I think Mike give good advice. You want different gauges fine, change them out after you solve the fuel gauge issue. If you have an issue that is literally anything other than the gauge, changing the gauge won't solve it. He also gives good advice on the temp wiring for testing. At the shop we use something called a power probe, which is eventually a high tech version of a temp test wire. You might trace it down in just a few minutes.

 

[WP29P4A]

For what you are doing this tool is essential. And it's only about $20 depending on brand. Having a volt/ohm meter is very helpful also.

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