QuestionHello Roland,
I'm a female who is very new to trying to find answers about auto problems over the Internet; so, let me thank you in advance for your patience with me and my explanation/question. :o) Of course, it goes without saying that, unless it something really, really simple to fix, I will have to take it to a mechanic to have it fixed. However, being female and naive about the mechanics of automobiles, unfortunately, I have been taken advantage of by some unscrupulous mechanics. So, I thought you would be kind enough to give me an idea of what might be wrong, what it will take to fix the problem, and an "approximate" cost before I take it to a mechanic.
In a nutshell, the odometer "display" in my 1997 Dodge Status, 5-speed, works sometimes and doesn't work at other times. I stress here, that whether or not the display is visible/lit up, the odmeter itself still records the milage accurately - so, the odometer is NOT broken; the problem is only with the display. Additionally, the tachometer does not work unless and until the odometer lites up. At times, when I turn the ignition key to the accessories position, the odometer lites up; yet, when I start the engine, the display goes off. Other times, the odometer display does not lite up when the key is in the assessories position, nor does it lite up when I start the engine. However, within five minutes or so of driving, the odometer display all of a sudden lites up and the tachometer needle automatically registers rpms. And, still, at other times, I can start the car and both the odometer display will lite up and the tachometer is registering.
Sometimes having my headlights on "seem" to effect the length of time it takes for my odometer to lite up. Just yesterday, after driving for more than 15 minutes with my headlights on and my odometer display off & tachometer on zero, I noticed that when I turned my lights off, the odometer immediately lit up and the tach needle immediately registered. Coincidental?
Let me say here that all other panel instruments are working perfectly without interruption of any kind - display included. Also, I did not have this odometer/tachometer problem until after a recent rear brakes drum and shoe replacement. Don't know if they are related in anyway or if this is just coincidental.
Roland, I am sooooo grateful there is someone like you online that is willing to give this kind of information out to the public! Can you please help me in some way with this?
Sherry
AnswerHello Sherry,
Welcome to the world of do-it-yourself/arm-yourself auto repair. Thanks for the detailed description of what is going wrong with the cluster as it helps in narrowing down the issues markedly.
There is no relationship of the cluster to the brake work as far as I can see. So focussing on the cluster, there are two systems that are needed for it to work: electrical power/ground wires, digital data bus wires that bring all the information to display or activate warning lights. Because the entire cluster doesn't shut down nor do any entire subset of data cease to function I believe that the problem is internal to the cluster wherein the two systems are subdivided to service the different gauges and bulbs. The manual doesn't show the details of the circuit board and its surface of interconnecting conductors so I can't be certain of my analysis. But the tachometer and the odometer/shift position indicator segment are shown as independent of oneanother. If the odometer doesn't work and the shift position indicator works then I suspect that there is a flakey connection of the data bus to that odometer unit, probably a crack in one of the electrical traces on the board that serves it. If the position indicator ceases to show when the odometer does similarly then I would suspect the power/ground wires to that area of the circuit board though it could be the data bus as well since both units need the data but. On the tach, I am uncertain if any other nearby unit is served along with it. But the fact that its malfunctioning is ganged to the odometer makes me believe that it probably the power/ground trace connector to it that is flakey which I guess says that same power/ground trace is at the bottom of both problems. That both seem to relate as well to the headlamps (which would modify the voltage momentarily when called on or off) adds to the theory that it is the power/ground system to the affected cluster units that is at fault.
This anlaysis would suggest that the cluster should be removed and the circuit board inspected for some cracks in the surface trace conducters to those two areas of the board and if possible repaired. Other wise a new printed circuit board or finding a used cluster in its entirety from a wrecking yard are the options.
There is a self-diagnostic check you can initiate as follows:
Depress the odometer/trip reset button and hold it while you turn the ignition key from off to run to start (momentarily, I don't think you need to start the engine but let the key return to the run position). Then 4 different Check functions will initiate. "chec" may appear in the odometer window. In chec 1 the tach should indicated in sequence 6000, 3000, 3000, 1000 while speedo, fuel and temp gauges do various things. The second chec will be of the warning lamps, the third will test the various segments of the odometer, and the fourth the transmission range selector segments. Let me know if anything unusual occurs.
It is a situation that you may want to contemplate whether to do anything about it or not. The tach and the odo are not so crucial that you need them all the time and there is a slight risk that in getting access to the unit and servicing it something else may be harmed. But it is a matter or choice and priorities.
I suspect that between an hour or two of labor and the parts this might cost $250 if things go well and the person who does it is competent. Then there is the downside of an incompetent on a fishing trip. So weigh those factors in deciding whether to followup on this. I'd be curious to know what you learn and decide to do.
Roland
