Modern Speedometers

[old-tank]

Modern Speedometers, specifically 1992 Mercury Marquis analog.(there are only electrical connections, no speedometer cable) The odometer quit working although the the trip odometer and speedometer is OK. Installed a used one and both the odometer and the trip odometer did not work. The place where I bought it says there are other issues with my car. Maybe if someone can tell me how these things work I can understand enough to agree or argue.

Willie

[Guest DeSoto Frank]

Willie,

I don't know too much about these except that there are sensors everywhere, and there might be a separate sensors for both the speedometer and the odometer... your friendly neighborhood Ford/Mercury dealer's service department might at least be able to tell you if all the speedo/odo/trip -meter functions run off the same sensor....

With some of the computer-euipped cars (such as my ex- 1985 Chrysler Laser) the computer stored a variety of fault & diagnostic codes which could be retrieved and interpreted with the help of shop manuals such as Haynes or Chiltons...the Chryslers had one of the idiot lights flash a series of code numbers, which were then indexed in the shop book. Some other makes need a "code reader" which can be obtained at Pep Boys or the like.

Or, you could take it to a good shop that does diagnostic work, if you know one, and have them check it out.

If you think the cable-less speedo is frightening, I've heard talk about making the throttle and steering controls "electronic" too - I think they call it "drive by wire"...

Personally, I do not want to be anywhere near an automobile whose steering is controlled electronically, without at least a mechanical back-up system...I think I'd want to maintain some kind of positive mechanical contact with the steering aparatus!

Good luck!

[Guest Albert]

You might be able to check out the local library, check the Chiltons manual on the electrics normally there is only one speed sensor in the tranni, so if the speedo work the odometer should as well. but check the diagrams and the troubble shooting guide from them, the Haynes or Clymer manual don't show enought detail.

[old-tank]

I found another used one and it works fine...

Thanks for the replies.

Willie

[Stanley735]

As to the drive by wire remark, it is closer than you think. The 1994 Ford F250 diesel and the 2002 F250 Diesel that I currently have use an electronic throttle. The pedal just works a rheostat for the computer.

Jim Showers

1921 Stanley 735B

[decembro]

Actually Saturn has had drive by wire since 2000 in their L series V6 cars. It features two throttle position sensors, one at the throttle body and one at the accelerator pedal. The Saturn Vue had electronic power steering, which if it fails, defaults to what would be the equivalent of hydraulic power steering which has failed. In other words, it's more difficult to steer than normal manual steering, but it's still controllable. Both systems work extremely well.