99 Tahoe shuts off while driving

[WSforeman]

I have a 99 Tahoe that keeps shutting off while driving. By that I mean its just like someone turned the key off. The motor quits running, radio shuts, off, A/C shuts off, etc. Just like you turned the key off. But it starts right back up!! I had the shop check it out and they did'nt get any codes and told me there was nothing wrong with it. However with wife and kids driving down the freeway I cant have it shutting down all the time!!!!! Any Ideas??

[Jeremy-WI]

You might have a loose battery connection, corroded battery cables, loose or bad ground wire. If its one of these, when the radio comes back I doubt it would have the correct time. It may even be a problem with your ignition switch, wiring or fuses under the hood(check IGN fuses)

[glenncof]

I had a loose battery cable once on a Range Rover and it was acting like demons had taken over. Alarm system was triggered, horn blowning, lights flashing ...

It was loose at the starter solenoid.

[WSforeman]

Whats the best way to trouble shoot the ignition switch? I replace the battery about 3 weeks ago and there was some corrosion on the cable that I cleaned up!

[glenncof]

WS,

So the clock and other non-ignition items still working, right ?

I would check schematic and measure voltage on circuits by probing selective fuses in the fuse box under the hood. It's intermittent so it will be tough to catch it. If I got desparate I would solder or clip (with fuse) a wire and run it into passenger compartment and hang my meter of it (lay on dash). Use a primary circuit like ECU feed.

I have disassbled steering column covers it the past and measured at the ignition switch also.

There probably is a fuse ahead of the ignition switch also, so check the feed to the switch.

If you are sure everything related to ignition is going off, I would say the switch is likely. I don't assume before throwing part, I verify before replacing anything.