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Rocky Hayne · 01-14-2012, 10:40 PM

Hello All, I am New to this site so I thought I would ask some RV'ers and possibly mechanics if they have a answer to my problem

I have a 31' National/Dolphin 1990, Class A, and my gas gauge does not work, I just bought it this last year and I have been remodeling it . My RV mechanic and I dropped the tank and disconnected the Fuel Pump and Sender, figured out moving the sender up and down the gas gauge does not work, so, I just installed a new one today.

Hooked all lines up per instructions with my mechanic and moved this float arm up and down and the gas gauge still is not working.
Thinking maybe it's on the cluster panel but it has a circuit board ????

Any suggestions would be really helpful and appreciated

Thank You,
Rocky

Dwight · 01-15-2012, 12:14 AM

You didn't say what brand chassis you have.
If you make a solid ground contact with the gas gauge wire that attaches to the tank gauge, your dash gauge should show full. If it doesn't show full, you may have a bad connection in the wire between the tank and the the dash gauge.

rgreen45 · 01-15-2012, 06:33 AM

Dwight is correct.

Also, if checking the unit with the tank/unit out of the chassis, make sure you ground the float assembly.

Mike Canter · 01-15-2012, 06:36 AM

Dwight is right on on how to tell if it is the gauge or the sender end. Take that wire off the sender and ground it out while someone is watching that gauge. With the ignition on and you pull the wire off the sender it should go max empty and when you touch that wire to ground the gauge should go to max full. If it doesn't move the gauge needle it is not at the sender (gas tank) end it is the gauge end.

Rocky Hayne · 01-15-2012, 09:39 AM

Quote:

Originally Posted by Dwight

You didn't say what brand chassis you have.
If you make a solid ground contact with the gas gauge wire that attaches to the tank gauge, your dash gauge should show full. If it doesn't show full, you may have a bad connection in the wire between the tank and the the dash gauge.

Good Morning Dwight,

Thanks for responding to my dilema. The chassis is a Ford, When my mechanic and I grounded the unit/Sender it went to Full.
We did this outside of the tank when we hooked up the wiring.
However, when we moved the float up and down the needle did not move?
We figured it would, we did ground it to a good source/frame, should I just put like 10 gallons in and see if it goes to half full, I already have about 27 gallons in it now, it is a 75 gallon tank

Thanks,
Rocky

Dwight · 01-16-2012, 01:58 AM

Rocky
Ford used a G-rotor-type pump that incorporated the fuel level sender during the years 1989 thru late 1997. The pump had a bad reputation for causing a vapor lock condition on days of very warm temperatures and with a fuel tank 1/2 full. Ford released a Technical Service Bulletin No. 97-23-9 dated Nov.10,1997 that announced the new turbine style fuel pump and sender assembly Part No. F6PZ-9H307-DA. The new pump assembly required a Part No. F7PZ-9A213-BA jumper harness to be installed to convert the original 3-wire harness to the 4-wire plug used on the new pump for motor home chassis built before 11/27/96. ( 11/27/96 thru 6/30/97 use jumper harness F7PZ-9A213-CA ).

The bad news is you have already reinstalled the tank assembly and have the tank 1/3 full of gas. Did you replace just the sender or the complete pump with sender assembly? The top of the old style pump has a 3-wire 3/4 circle shape wire connector and the top of the new pump has 4-wires in a straight line connector.
Dwight

jlyon69 · 01-16-2012, 05:04 AM

I dont know if this is relevant but suppose it could be. Had a '91 Ford chassis Four Winds E-350. Gauge didn't work when purchased. Had a mechanic check it out and he said the "slosh modual" was shot.

This modual plugs in on or around the gauge in the instrament panel. This was circa 2006. Ford said they weren't available any longer. Tried a few local junk yards with no luck.

Rocky Hayne · 01-16-2012, 10:19 AM

Quote:

Originally Posted by Dwight

Rocky
Ford used a G-rotor-type pump that incorporated the fuel level sender during the years 1989 thru late 1997. The pump had a bad reputation for causing a vapor lock condition on days of very warm temperatures and with a fuel tank 1/2 full. Ford released a Technical Service Bulletin No. 97-23-9 dated Nov.10,1997 that announced the new turbine style fuel pump and sender assembly Part No. F6PZ-9H307-DA. The new pump assembly required a Part No. F7PZ-9A213-BA jumper harness to be installed to convert the original 3-wire harness to the 4-wire plug used on the new pump for motor home chassis built before 11/27/96. ( 11/27/96 thru 6/30/97 use jumper harness F7PZ-9A213-CA ).

The bad news is you have already reinstalled the tank assembly and have the tank 1/3 full of gas. Did you replace just the sender or the complete pump with sender assembly? The top of the old style pump has a 3-wire 3/4 circle shape wire connector and the top of the new pump has 4-wires in a straight line connector.
Dwight

Hello Dwight,

Yes all the numbers you have quoted for Sender/Float and Wire Harness is exactly what I recreived, I purchased them through Rock Auto Supply back East. It also included Instructions for installations figure 1 and figure 2, figure 1 was my situation to where we soldered or butt clamped the 3 wires and then shrinked tube over them. Mine required to hook up the 3 wire connections from the 4 wire/new assembly
You had mentioned that when you Ground the unit that it would go to FULL and thats exactly what happened, does this mean it will work and kick in when I drive it and put more gas in ???. Or, could it be the dash gauge thats not responding, it is on a computer board/dash cluster.

Thank You for your advise and attention !!!

Rocky 408-802-2124/Cell

Dwight · 01-16-2012, 10:41 PM

Rocky
When you turn the ignition switch on, do you hear the fuel pump run for 1 or 2 seconds?
You should be able to hear it each time the switch is turned on from the off position.

Both the in-tank pump and float level are connected to the ground connection thru the wires that you plugged into the top of the tank. On the inside left frame near the back you will find a multi-wire connector and very close to it is a grounding wire screwed into the frame. I believe this could be the ground for the pump and sender. Be sure it has good contact and protected from rusting.

Rocky Hayne · 01-17-2012, 12:28 AM

Hello Dwight,

Yes we did hear the Fuel Pump run for a second or two, so we know thats working plus I ran the MH and the Generator for about 20 minutes, so I know evrything else is in operating condition.
I will check the grounding wire to make sure I have a fresh/non rusted grounding point. That is if I can see it from the underside, I will try this tomorrow and get back to you and let you know what I discovered. If you have any other ideas to the Gas Guage not working, Please advise.

Thanks again,

Rocky

Dwight · 01-17-2012, 10:10 AM

Rocky
I've run out of ideas. You may have to drop the tank again. The gauge should have worked when you moved the sender arm before you installed the pump/sender into the tank.
Let us know what you find.
As Always, Dwight

jlyon69 · 01-24-2012, 06:20 AM

Rocky,

Have you found the problem yet?

Rocky Hayne · 01-24-2012, 11:15 PM

Quote:

Originally Posted by jlyon69

Rocky,

Have you found the problem yet?

No, I have not had a chance to check the wiring and test it, hopefully I will be able to in the next week or two.
I think I am going to open the dash panel and check the gas guage wire with one that works, like the battery or oil gauge, it might be a bad gauge, (keeping fingers crossed).

Thanks,
Rocky

Mike Canter · 01-25-2012, 06:54 AM

Rocky, you never did tell us what happened when you grounded the gas gauge sensor wire on top of the tank. Did the gauge on the dash move? Then what happened if you disconnected the wire from the sender?