Tow/Haul Switch

**cberentsen** · 05-18-2009, 09:23 PM

Tow/Haul switch inoperative.

99 GMC Sierra 1500 4x4.

Owners manual doesn't tell which of the three fuse blocks contain the fuse, perhaps combined with another wiring circuit? Neither does the Chilton's even address the Tow/Haul switch.

**Springthing** · 05-18-2009, 10:16 PM

I'm not even sure what switch you are talking about so I won't be of much help! But if all else fails grab yourself a meter and go from one fuse to the other checking for continuity on all the fuses.

**cberentsen** · 05-18-2009, 10:26 PM

Originally Posted by Springthing

I'm not even sure what switch you are talking about so I won't be of much help! But if all else fails grab yourself a meter and go from one fuse to the other checking for continuity on all the fuses.

Thanks Steve!

**cberentsen** · 05-18-2009, 10:28 PM

Originally Posted by Springthing

I'm not even sure what switch you are talking about so I won't be of much help! But if all else fails grab yourself a meter and go from one fuse to the other checking for continuity on all the fuses.

It's the button at the end of the shift lever that locks out overdrive when towing.

**Springthing** · 05-18-2009, 10:36 PM

ah! I know what you mean.. I don't have it so wasn't sure if yours did.

Well, hopefully someone will come along and be able to give advice. I'd say if you have a meter just start going to town on checking for continuity. Should take you more than 5 minutes or so.

**trimhalifax** · 05-18-2009, 11:34 PM

You might want to check for broken wiring. Pop off the cover under your steering column and check the two wires near the shift lever. These have a habit of breaking due to movement of the lever.

**pmf608** · 05-18-2009, 11:52 PM

Originally Posted by trimhalifax

You might want to check for broken wiring. Pop off the cover under your steering column and check the two wires near the shift lever. These have a habit of breaking due to movement of the lever.

I agree on this one. They are two very small thin wire wrapped in a larger casing. I had to cut them to replace my shifter boot, and there is NO extra slack on them. i could see them breaking. I had to extend them to keep them from shorting when I shifted out of park once I fixed them. I would check this and if one or both wires are broken, I would solder in some extensions, seal them up, and you should be good to go.

**cberentsen** · 05-19-2009, 03:31 AM

Thanks to all of you!
cberentsen

**woodbw** · 06-02-2009, 11:11 PM

cberentsen did you find a problem with your wiring. My 06 just up an quit working over the winter. Only use it when camper is loaded and the switch did nothing.
QUestion for you is, when you switch on ignition does the light come on during the light test? My light does not so was thinking burnt out bulb, will road test to see if shift points are diff\rent soon.

Brad