my speedometer instantly jumps to 120 and i'm not moving!? i removed the instrument cluster and took off the back panel with all the instruments (so i could replace the trip reset button, which i did successfully). i then put it all back together and speedo thinks i'm speeding! i noticed a few odd things.
1. the metal tube that goes from the speedo off to the right corner (when looking at from front) has a spring and a "button" thing that goes into the front cover. on my cover it looks like there was a clear plastic socket that this fits into but it's kind of shattered and has been since i've owned the car (about 7 years).
2. there is a white wire with an orange stripe that wasn't plugged into anything. the yellow wire was plugged into the lower tab (i think) just to the left of the speedo. when i re-installed the cluster i plugged the white/orange into the top tab and the car wouldn't start! unplugged it and the car started (if i try to plug it in it stalls the car). started to drive and the speed needle jumped all the way to 120 and stayed!
i was able to get the needle back to 0 but when i go about 3 mph it jumps to 120.
did i break my speedometer? anyone had any experience with this?

I was really hoping Paul already gave you the bad news...

The "white/orange" wire is for the tachometer. If it is plugged in the speedometer, the electronics get fried. There are literally hundreds of posts on this, so don't feel alone. The wire is really white/red.
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Art Benstein near Baltimore

Accept that some days you're the pigeon, and some days you're the statue.

thanks, i'm a little colorblind. makes the electronics a bit difficult. went to the salvage yard and all i could find was a 1990 sedan speedo. decided to replace the whole cluster. i have read that the sedan is different from the wagon. how much will it differ? should i go slower than the speed limit or faster? to add to it, i put 740 turbo wheels on for 6 mo. of the year. how screwed up will it be?
also, is there a simple way to roll back the odometer - the new one is about 50,000 mi further along than the old one?

thanks

The easiest way to deal with the odometer is what Art recommended. However, I made the same mistake back in 2002 and it actually damaged the speedo "motor"/actuator coil. If you want to modify the mileage reading of the odometer, the following steps will get you there... but remember, carfax is always out there, so be honest!

1: Remove the circuit boards from both sides of the ODO assembly, do NOT cut or remove wires, just get them out of the way.
2: Below the ODO number wheels, you will find a series of gears between each wheel on a metal shaft.
3: Push the shaft that the gears live on out one side or the other, as the shaft moves out of the way, remove the gears one at a time and keep them in ORDER!
4: Roll/set the ODO display wheels to the proper mileage.
5: Start pushing the gear shaft back in while reinstalling the gears one at a time in the proper original order.
6: Reinstall the circuit boards on both sides and the job is done.

jorrell
ps. I wouldn't put this info out there if it wasn't for Carfax, which I highly recommend to anyone considering the purchase of a 240 as I've run into three of them that were er, uh, "rolled back".

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92 245 287K miles, IPD'd to the hilt, 06 XC70, 00 Eclipse custom Turbo setup...currently taking names and kicking reputations!

seems like it might be a waste of time - since i plan on keeping this car till the end (hope i can keep that far off in the future). my main reason was to be able to have an authentic celebration when the car hit 200,000. it may not be so exciting when the odometer is reading 242,456 or something.
thanks for the info - maybe i'll try it out.

Its never a waste of time to have the ODO show the proper miles! When we purchased a 92 245 with 236K miles, I gutted and rebuilt the car to ZERO mile status including paint. Last week, Bleen hit 286K miles and it was time for the timing belt replacement and fluid flush.

Please note that adjusting the ODO reading takes about five minutes and no special tools are required! Just do it to stay honest to the car itself!

jorrell
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92 245 287K miles, IPD'd to the hilt, 06 XC70, 00 Eclipse custom Turbo setup...currently taking names and kicking reputations!

you're right. pep talk appreciated. looking forward to doing it this weekend.

I only pointed out the wire color as it would help you or others search the archives on the subject if correct. It also would match the wiring diagram ID. Besides, doing the work behind that cluster is all by feel -- blind if you will - anyhow.

It is possible you could swap the electronics and keep your old speedometer with its odometer reading. Folks here do essentially that when they replace the odometer gear -- a frequent repair. Actually changing the odometer takes a bit more patience and some skill.

If you decided to live with it, don't fret over the <5% difference. Just run through one of those "your speed is..." signs and calibrate your driving.


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Art Benstein near Baltimore

The math professor went crazy with the blackboard; he did a number on it.

The first thing to check is to make sure the little connector on the back of the speedometer is firmly plugged in.

A loose contact will cause that, there are others but this just popped up.

You can reach it by laying on your back and easing your arm up to the back of the speedo.

No need to pull the cluster to check the connection.

Regards,

Paul