Western-Star

Q I have a 1998 Chevrolet Blazer. Lately the odometer and the transmission displays flicker and sometimes they go out all together. If I tap on the cover they come back on.

Also, the odometer sometimes reads 000000.

If turn off the engine and restart, the odometer goes back to its' original reading. Then sometimes it will only show half of the numbers.

A couple of times the tachometer went all the way over to the right and then back down after I tapped on it.

There seems to be a loose connection or a faulty switch. I've taken the truck to my local mechanic, but he says he's not able to fix it.

Do you think the trouble is computer-related or something else? M., E-mail.

A The technician who explained that he couldn't repair the trouble is correct. The instrument cluster is a unit that is sealed at the factory.

Within the housing, there is a microprocessor, circuitry and indicators. Parts are not available for field repairs at independent or dealership repair shops.

When the unit malfunctions a technician checks the electrical power supply and connections to make sure the cluster is receiving power and information from sensors and computers.

If tests find that the instrument panel is receiving all the necessary information for proper operation, the trouble is inside the cluster.

All he can do is replace the unit. If there is a problem in the wiring to the cluster or a sensor has failed, he can repair those problems but can't repair anything inside the cluster.

He can send the unit to a repair shop that specializes in speedometer repairs or he can order another cluster and install the replacement.

If you are sure the trouble is inside the cluster housing and are an avid do-it-yourselfer, it takes about an hour to remove and replace the unit.

You might consider ordering a replacement unit. Check with your local dealer or independent repair shop to learn where they get replacement units.

Also, you can find shops on the Internet that tackle the work of remanufacturing the unit.

Internet Repair Manuals

Q I read where, for about $20 a day, I could download detailed repair information but I don't remember if it was in your column or somewhere else.

Do you know where I can find internet repair manuals? L.W., E-mail.

A You came to the right place. There are online subscription services.

You can receive all the information about your car that you need and then some.

You can subscribe to Web sites that professional mechanics use for all of their repair information that encompasses just about every vehicle traveling the roads on the planet or to do-it-yourselfer sites specific to one vehicle that offer all the information that a professional mechanic accesses.

The most popular professional technician and do-it-yourself auto repair Web sites are www.eautorepair.net, www.alldata.com and www.chiltondiy.com.

The cost varies, but it is much less than $20 a day.