98 S10 Blazer dash/cluster issues

I just bought a 98 Blazer to use as a daily driver and the dash is all jacked up. I decided today to pull it apart and see if I could figure it out, here's the symptoms. The vehicle runs like a top, no bad noises or stumbles. The dash on the other hand does the following. When I unplug the plug at the top of the cluster and plug it back in, the water temp, gas gauge, oil pressure and voltmeter work. The next time I start it the water temp and fuel gauge won't work. The following lights are on with the key on or off Check gages, gate ajar, ABS, security, seat belts, air bag, brake, service 4wd, low fuel and the battery diagram on the dash. The tach and speedo do not work at all. When I turn on the key though, the tach jumps and then goes back to 0. The ABS light does turn off when the key is off. The turn indicators and hazard flasher indicators do work properly.

Sorry for the long winded question.

Thanks in advance for any help,
Chip.

BTW: Is there a section to post intro's?

I forgot to post in the initial post, three of the wires on the plug to the dash have running voltage 13.8v approximate to them and 12V when the key is on. When the key is off, one wire has 12V to it.

These trucks are notorious for Ignition switch problems, which will display many of the symptoms you are describing. There are many different symptoms with the ignition switch and no two are the same. If you do a search on this Forum for ignition switch, you should get a long list of posts to read. I would look into the igition switch and you will probably find your culprit.

Thanks Rick, I'll search the site for ignition switch problems.