Speedometer Problems

littlejohn2458 · 07-16-2007, 11:40 PM

Hello Everyone
I have a quick question for you all. i have a 1998 Ford Windstar 3.8L. Anywho...
When i drive i notice that the speedometer is intermittent. Is what happens is that it stops working and then works good. When the speedometer is working good the transmission shifts good with no problem and it drives smooth. When the speedo is not working right, the engine rev's really high and then it "Clunks" into the next gear. Also when the speedo isn't working right, I noticed that the cruise controll does not work. How is all this related and how do i Fix it. Ive done a lot of research and it sound like the VSS might be bad? if it sound like the vss could you let me know and also does anyone have a web sight or a picture of where it is located. I can not find diagrams anywhere and i do now know what it looks like or where it it located at/
Thanks in advance,
John

littlejohn2458 · 07-16-2007, 11:44 PM

just to add. I just red a thread about a cruise control problems, My brake light has been on since i got the vehicle.... Not the abs brake light but the hand brake light. (unless there the same). Would a bad switch be the cause of this problem? also i forgot to mention when the vss is bad does it make the Service Engine Soon light come on?

chris1871 · 06-15-2008, 01:40 PM

I just started experiencing the same problem in the last couple of weeks with the speedometer not working and then yesterday with the transmission acting up. Does anyone have a solution to this issue? My wife is worried that the transmission is going bad and may need work while I think it is related to the speedometer acting up.

Any help?

Thanks.

vindctar · 06-15-2008, 02:41 PM

Model year and mileage of your car?

holesaler99 · 06-15-2008, 02:47 PM

Hi, I am not an ASE expert but here are a couple of things; to test your instrument cluster...hold down the reset button on the speedom...and then turn the key to on position- the display should say test..now press the reset button and it will show you some information...see if all your gauges respond correctly and if all the bulbs in the speedom come on..if not..try replacing the cluster..most likely will need reprogramming...now..when you say your speedometer is not working..do you mean the whole thing? or just lights going crazy and gauges going crazy?..also if you want handy information about your mini van..go to autozone and pick up the haynes repair manaul..almost all the information you will need for troubleshooting.

BroncoJoe19 · 06-16-2008, 05:32 AM

Chris,
LittleJohn was def on the right track for his van, it is a shame that no one responded to him.
One may goto to AutoZone.com - Get in the Zone! and enter the year model and engine for his van. Then lookup VSS for both what it looks like and for its location. VSS stands for Vehicle Speed Sensor.

The computer uses it, and the Throttle Position Sensor TPS to determine shift points in the trans. The MAF sensor may also come into play. Also vacuum leaks.
Good luck

BroncoJoe19 · 06-16-2008, 05:44 AM

Checking for vacuum leaks.
Some of the sensors and some of the actuators either read the amount of vacuum, or use vacuum to move controls, therefore it is important to the proper functioning of the engine that your vacuum system is fully intact. Otherwise one may get codes falsely indicating that there is a problem with a controller/actuator, or a sensor when in reality it is caused by a lack of vacuum.

Look at your rubber vacuum hoses (they are about 1/4 - 3/8 inches in diameter, if they are dry rotted or cracked, replace them. IF they slip on/off of their connectors too easily, they may have stretched out a little bit, cut the ends off, and put them back on.

You may listen for a leak. Sometimes using a cut off piece of garden hose is a good aid to listen with. Sometimes a cardboard tube (like from gift wrapping paper) is helpful. Just remember that whenever you stick your head inside a running engine compartment, that you are not wearing any loose clothing or jewelry that can get caught.

Another suggestion is to use a spray can of carb cleaner and spray around the bottom of the intake manifold, and the base of the throttle body assembly. IF there is a leak, you should hear a change in your engine.

BroncoJoe19

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GraybeardAv
Senior Member

That's good, Joe. I prefer to spray a mist of water around on the engine. A vacuum leak taking in water mist will cause the engine to stumble. And there's no danger of fire from hitting a hot exhaust.

GB