Last post on Jun 07, 2011 at 3:38 PM
You are in the Chrysler/Plymouth Voyager, Dodge Caravan
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Dodge Caravan, Chrysler Voyager, Plymouth Voyager, Van
#1 of 1 99 town and country fuel gauge mystery no one can solve
Jun 07, 2011 (3:38 pm)
99 town and country 3.3 liter head scratcher! The vehicle has a fuel gauge that does not function , even with a brand new sending unit , no broken wires , and fully functioning fuel gauge. Please read this entire post because I have been there and done that and even the dealer has no clue.
Heres the deal, all of the following have been verified...
fuel gauge in cluster works , no broken wires , sending unit works fine , fuel pump works fine..... But the plot thickens.......
The factory wiring harness has the following wires at the fuel pump connector....
Black = ground
Red = hot
dark blue = bcm
purple with black tracer - THE MYSTERY WIRE!
I have everything at the fuel pump connector that it should have , in fact , the only wire that causes the fuel gauge to move via testing, is the mystery purple and black tracer that mitchell on demand says doesn't exist , and the dealer says that doesn't matter, and add to this fact that 2000 and up fuel pump sending units do in fact have a 4 wire connector with four pins on the sending unit.
However, the sending unit for this model year says it only requires the 3 wire connector, and yes, i have tried the newer sending unit with all four pins and it still doesn't work.
But get this.....
If i connect the purple wire with black tracer to the dark blue wire, the gas gauge will pin itself so I know the gauge works , now it gets even more perplexing.....
the only wire on this harnes connector that cause the gauge to move , is the only wire in the connector that doesn't have a pin in the fuel pump sending unit!
it is in the wiring harness connector , but where you plug in into the fuel pump unit , this pin is missing from the factory.
So again , no broken wires verified by continuity testing , fuel gauge does actually work as i can see it go full scale when i i connect the purple and blue wires together, which also rules out broken wires, fuel pump power and ground are fine , as are the rest of the gauges , fuel level is the only one not functioning.
Different brand new units do not change anything which rules out a manufacturing defect on the new pump and sending unit assemblies , I am about ready to toss an instrument cluster at it and hope for the best , but again , all other gauges work , and i can get the fuel gauge to go full scale by connecting blue and purple so the gauge obviously works.
And , I still cannot find a diagram that contains the mystery purple wire with the black tracer that moves the gauge , and I also cannot find a pinout diagram anywhere which tells me what this wire does and where it goes and why it moves the fuel gauge on its own , but not when actuated by the sending unit (which would actually be impossible because it goes to an empty pin location in the new fuel pump unit.
Anyone who can solve this mystery deserves a case of cold ones on me.