I have a 1987 Cougar with 40K on it, The digital speedometer
> doesn't show any reading. The light is on and the bulbs, which cost $12
> each and there are two, test OK. Also....where is the memory stored for
> the mileage? If I put a new instrument cluster in will the mileage still
> be 40K? Any help will be appreciated. Thanx, Dave.
>
"Dave Pietrzak" wrote
It's a back-lit LCD, so even if the bulbs are burned out you should be able to see something (got a flashlight?). Are there any numbers at all, or just a big blank green area where they're supposed to be? Does it do it's "diagnostic" thing where all the numbers and words flash for a second when you turn the ignition on?
Here's what I found...so far....The #17 15amp fuse was blown. But...the person I bought the car from stuck a 20amp fuse in there. So now this is telling me that there is a more serious problem. The 15amp is holding for now but I don't drive the car a whole lot. I did the speedometer/odometer test and all tests passed. The only other weird thing is while the car is sitting still, but running, the speedometer will register like 1mph...3mph....2mph...1mph. All while the car isn't moving. I was going to try the speed sensor. Thanx, Dave
"Dave Pietrzak" wrote
#17 supplies power to the speedo, AND (if applicable)..... Cruise control amplifier. A/C / heater switch (for the WOT cutoff relay) or EATC blower controller and "brain". Lamp-out module. Rear window defog switch/relay.
So, several possible paths for a short circuit to blow the fuse. Is there an aftermarket stereo/amp in there? Where does it get its power?
Or an internally broken wire / loose connection on the way to the sensor that keeps opening and closing the circuit (with the engine vibrations), making the speedo think it's getting a normal pulsing signal.
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