95 Tahoe - Transmission or Electrical ? with check gages lamp on

[35chevy]

1995 Tahoe 4WD with 5.7 motor and 4 speed auto transmission with 95K miles and some trailer towing use. I observed transmission gear selector lamp flickering and speedometer needle jumping intermittently while driving at highway speeds. 100 miles later things took a turn for the worse when I observed the speedometer, tach, and transmission selector lamps had quit permanently, "Check Gages" lamp was turned on and the transmission was stuck in high gear (3rd or Overdrive ?). From a dead start, the transmission is in 3rd or 4th gear, does not shift at all. Manually selecting 1st or 2nd gear does cause the transmission to operate in a lower gear but not sure if it 1st or 2nd, then manually shifting to 3rd or 4th gear range causes it to shift to the higher gear. Reverse gear is working. The "check gages" lamp is now turning on & off intermittently in all gear ranges and seems brighter in the lower gear ranges but still no gear selector lamp, speedo or tach. The gear selector dash lamp does work with the ignition switch turned on and the motor not running but goes off after starting the motor. I've poked around with various wiring harness connectors to no avail.

Hopefully some of you know these symtoms and have some some advice to offer. Thanks in advance for your help

[Rbraczyk]

Holy crap. It sounds like something severe went wrong. Tranny soleniods? Im lost.

[Mikado14]

Check the operation of the alternator.

[Fireplug]

ecm or ground problem or lack of alt power

[broughy84]

Sounds as though you have a problem in the transmission. Sounds to me like the computer sensed something it could not fix and threw your transmission into "LIMP" mode. Get to a shop and have 'em hook you up to a computer and see what is going on.

[Gooseneck]

If you lose all electrical circuits to your 4L60E transmission you will have 3rd gear starts and you can manually select 2nd gear (Limp Home Mode). GM had issues with faulty ignition switches that could cause your problems.

[Faze2183]

ya my moms ignition switch went out and did that same thing and hers is a 97 when they first came out with the pasnger side airbag

[Faze2183]

btw did you have more go in reverse then in drive? because if so thats whats my moms subby did...

[Jeremy-WI]

Check battery cables for corrosion, check fuses(trans fuse), check electrical connector on side of tranny. And check voltage at trans fuse with ignition switch on, voltage at fuse should be the same as battery voltage with the ignition on, if it isn't replace the switch