Turn signal flasher stuck on

[tgwright]

I have a '99 Tahoe, 2WD, 4DR, with 112,000. During a recent move from Florida to Ohio I was towing a Uhaul trailer. During the last 75 miles of the trip the turn signal flasher stayed on after signalling a lane change. The turn signals were not flashing, but the flasher was clicking. The turn signals work normally when I select either right or left turn signal, and the four way hazard lights work normally, but the flasher continuously clicks at the normal rate all the time whenever the ignition is on. The service manual looks like this is a relatively simple system, but I can't come up with an idea as to what condition would cause this, other than perhaps a damaged flasher. It is a solid state unit, not the old style silver can that plugs in. Anyone have an idea?

[MT-2500]

Originally Posted by tgwright

I have a '99 Tahoe, 2WD, 4DR, with 112,000. During a recent move from Florida to Ohio I was towing a Uhaul trailer. During the last 75 miles of the trip the turn signal flasher stayed on after signalling a lane change. The turn signals were not flashing, but the flasher was clicking. The turn signals work normally when I select either right or left turn signal, and the four way hazard lights work normally, but the flasher continuously clicks at the normal rate all the time whenever the ignition is on. The service manual looks like this is a relatively simple system, but I can't come up with an idea as to what condition would cause this, other than perhaps a damaged flasher. It is a solid state unit, not the old style silver can that plugs in. Anyone have an idea?

If all else is working normal try a flasher.
If that does not do it post back.
MT

[tgwright]

Thanks for the thought, MT. I did that, and much to my surprise the new flasher also flashes non stop. This is indeed weird. I was hoping someone else here has had the same problem and could save me a pile of time troubleshooting. I suppose I'll need to start at the flasher receptacle and trace up the circuit to find a point where there is a wire contacting ground and fooling the flasher into thinking that the TS switch has been activated. My first suspect must be the wires that go TO the TS and hazard switch assy. The reason I doubted this as a cause was that I thought the fuse would have blown if the power went from the flasher directly to ground somewhere instead of having the load of three lights on it.

[MT-2500]

Originally Posted by tgwright

Thanks for the thought, MT. I did that, and much to my surprise the new flasher also flashes non stop. This is indeed weird. I was hoping someone else here has had the same problem and could save me a pile of time troubleshooting. I suppose I'll need to start at the flasher receptacle and trace up the circuit to find a point where there is a wire contacting ground and fooling the flasher into thinking that the TS switch has been activated. My first suspect must be the wires that go TO the TS and hazard switch assy. The reason I doubted this as a cause was that I thought the fuse would have blown if the power went from the flasher directly to ground somewhere instead of having the load of three lights on it.

You might unplug the turn signal switch to eliminate a problem there.
Or for help on the wiring the all data DIY repair info sub would help.
Link below .
http://www.alldata.com/products/diy/index.html
Good luck and let us know how it goes.
MT

[tgwright]

It looks like a need to replace my multifunction turn signal switch. Can anyone tell me if 1) I need a special wheel puller to remove the steering wheel, and 2) can I R&R the turn signal switch without removing the upper steering column shroud which seems to require removal of the ignition switch first?

[horse482]

If it is the older body style then you should not have to remove the steering wheel to replace the mutli-function switch, there shoud be two screws on the bottom of the steering colum cover just behind the steering wheel. The two halfs (top and bottom) should just pull away exposing the switch.

[tgwright]

It's a '99. The shop manual says the ignition switch needs to come out to remove the top column shroud, and it says the steering wheel needs to come off to remount the switch. We all know that the manuals don't always reflect reality, so if someone has done this, I'd like to hear from them. One other challenge I'm having is trying to unplug the turn signal switch cable. The plug along the steering column into which the multifunction switch plugs has about 40 or 50 wires going into it, and it seems to have some sort of locking or latching mechanism on it. Has anyone actually unplugged this?

[MT-2500]

Originally Posted by tgwright

It's a '99. The shop manual says the ignition switch needs to come out to remove the top column shroud, and it says the steering wheel needs to come off to remount the switch. We all know that the manuals don't always reflect reality, so if someone has done this, I'd like to hear from them. One other challenge I'm having is trying to unplug the turn signal switch cable. The plug along the steering column into which the multifunction switch plugs has about 40 or 50 wires going into it, and it seems to have some sort of locking or latching mechanism on it. Has anyone actually unplugged this?

Mr mitch on demand repair info gives about 3 hrs labor.
So it is not easy.
Steering wheel does need to come off.
So watch that air bag. Study up on air bag disable procedures in repair manual. Them things can save your life or kill you in a split second.
On the ign switch it says to remove it if necessary.
Study on it when the wheel is off. you may or may not have to pull it.
Some times it helps to get the new replacement part and look at it to help get the old one off.
I am not sure what repair info you have but the All Data DIY repair info sub IS A GOOD ONE.
http://www.alldata.com/products/diy/index.html
Also some info and pictures can be found on the Auto zone www. site.
Good Luck and let us know how it goes.
MT

[MT-2500]

Originally Posted by tgwright

It's a '99. The shop manual says the ignition switch needs to come out to remove the top column shroud, and it says the steering wheel needs to come off to remount the switch. We all know that the manuals don't always reflect reality, so if someone has done this, I'd like to hear from them. One other challenge I'm having is trying to unplug the turn signal switch cable. The plug along the steering column into which the multifunction switch plugs has about 40 or 50 wires going into it, and it seems to have some sort of locking or latching mechanism on it. Has anyone actually unplugged this?

Here is all of the info I could find on it.

MULTIFUNCTION SWITCH

Removal
1) Ensure multifunction switch lever is in center of OFF
position. Disconnect negative battery cable. Disable air bag system.
See appropriate AIR BAG RESTRAINT SYSTEMS article. Remove steering wheel. See STEERING WHEEL. Remove knee bolster, if necessary.
2) Remove bolts/screws and lower column cover. Remove bolts/screws and upper column cover. Remove lock cylinder, if
necessary. See LOCK CYLINDER (FUNCTIONAL). Remove wiring harness strap. Disconnect steering column electrical connectors. Disconnect multifunction switch Gray and Black connectors. Remove multifunction switch from vehicle.
Installation
Install multifunction switch. Using small, flat-blade
screwdriver, compress electrical contact and move switch into
position. Ensure electrical contact rests on cancel cam. See Fig. 7 or 8. Tighten multifunction switch screws to specification. See TORQUE SPECIFICATIONS. To complete installation, reverse removal procedure.
MT