Speedometer reads 45 sitting still

I have had the same old problem that everyone else has had with the dash lights going out for the past two years (will be fixing after reading forum), but now the speedometer is about 40+mph above whatever I am driving. If I am doing 50mph it it telling me that I am doing 90 etc. Also the fuel gauge is reading way above "F" once the key is turned to the last position prior to starting. If the key is in accessory the fuel gauge reads 1/2 tank. " When I disconnected the fuel sending unit the needle would go from way above "F" to 1/2 tank. Would this be another result of the solder joints going bad? I have read that a bad relay for the rear window defroster can cause faulty readings on the instrument panel and didn't know if anyone else has had this problem. Thanks for the help.

97 Town & Country 3.8L 145,000 miles
Reply to
comesummer
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For the speedometer problem, do this:

Start with ignition switch off (in "lock" position). While holding the odometer reset stem in, turn the key to the "unlock" position (that's the first click of the ignition switch) - continue to hold the odoemter reset stem in for about 3 seconds. You'll see a self-test of the instrument cluster begin - part of which includes a dance of the gage needles to preset positions. At the end of the needle dance, the tachometer needle will be in its proper position.

In a nutshell, here's what happened (no need to read further if you don't want to know the "why" of what happened): The needle somehow got thrown into the wrong position (say - a jolt to the vehicle with power turned off). The gage needles are driven by motors that have any one of three unique positions (at 120° intervals) for a given set of their control signals. Everything is great until/unless the needle gets into the wrong 120° sector - and then you see what you are now seeing. Putting the cluster thru the self-test (needle dance) tries to force the needle clockwise past the peg, but since it is blocked by the peg, the needle pops back into the correct sector and forever will read correctly (unless something jolts it into the wrong sector with ignition power not applied to the cluster).

Bill Putney (To reply by e-mail, replace the last letter of the alphabet in my address with the letter 'x')

Reply to
Bill Putney

Bill, thank you for the reply. I removed the instrument cluster today and resoldered the pin connections. This appears to have fixed the dash lights from going out and perhaps I will no longer have to beat itrunaround . I reset the panel as you instructed about 4 seperate times with no results(no codes just 999). Both the speedometer and fuel gauge needles did their dance but they always go back to the same spot until I turn the key off. When the key is turned off there is about a two second delay then you can here a click and both needles fall back to zero. The click sounds like it is comming from the instrument panel or behind it(not the engine compartment). I reset the PCM as well as the BCM and when that didn't work I disconnected the battery for about

10 minutes with no results. Could this be the result of two years of poundings on the dash? It could be coincidence but about the same time this happend the van will run like *hit for about 10min when you first start it up. I just had the fuel pump and filter changed because it wouldn't run so I belive that is from trash in the tank. There is a code 11 on the PCM which I belive is a crank position sensor which I will change here shortly. Any ideas?

Almost forgot, I changed the rear window heated backlight relay (rear defrsot)which did nothing but cost me $17.00. When I hit the defrost the rear wiper comes on.

Reply to
comesummer

I'm out of ideas, except bad BCM.

Bill Putney (To reply by e-mail, replace the last letter of the alphabet in my address with the letter 'x')

Reply to
Bill Putney

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