Community Forums

RVNewbie55 · 01-13-2015, 12:35 PM

Does anyone know how to disable the speedometer from recording mileage on a 2006 GMC 3/4ton 4x4 Duramax while being flat towed?
Bob

cc8375 · 01-13-2015, 01:11 PM

Sorry... do not for sure. On older cars you could reach up and unscrew the cable behind the dash. Caution is needed when reconnecting that the Lead sticking out of the cable seats well in the Speedometer.
Over the years, I found it easy to keep a small note book and record all towing mileage rather then disconnect. In Later years (since 1999) miles did not record on vehicles when towing.

newmarpusher · 01-13-2015, 01:35 PM

Quote:

Originally Posted by RVNewbie55

Does anyone know how to disable the speedometer from recording mileage on a 2006 GMC 3/4ton 4x4 Duramax while being flat towed?
Bob

Federal law makes that VERY difficult to accomplish any longer.

Even if you could figure out a way to do it, it would be illegal.

slowmachine · 01-13-2015, 01:51 PM

I think that the speedo/odo get their signal from an ABS speed sensor. You won't be happy if whatever you're doing activates the brakes at highway speed.

stuhly · 01-13-2015, 01:55 PM

That 2006 GMC should not register miles while the key is off.

newmarpusher · 01-13-2015, 02:21 PM

Quote:

Originally Posted by stuhly

That 2006 GMC should not register miles while the key is off.

I know that my 2012 Jeep Wrangler doesn't log miles as long as the key is off. If it requires the key to unlock the steering wheel the OP might be stuck though.

UFO Pilot · 01-13-2015, 02:25 PM

Quote:

Originally Posted by newmarpusher

Federal law makes that VERY difficult to accomplish any longer.

Even if you could figure out a way to do it, it would be illegal.

There are sure a lot of us violating federal law!

My CRV doesn't record towed mileage and it came that way from the factory.

gripper · 01-13-2015, 02:28 PM

I believe most cars have electric speedometers, so they do not register when the proper fuse is pulled, as per the manual. That's what happens, with my Saturn Vue.

newmarpusher · 01-13-2015, 02:44 PM

Quote:

Originally Posted by UFO Pilot

There are sure a lot of us violating federal law!

My CRV doesn't record towed mileage and it came that way from the factory.

You misunderstood me. I met that tampering with the speedo was illegal, not towing without registering mileage. I tow my 2012 Jeep Wrangler without registering mileage. That is the way it's is designed. I didn't have to tamper with it in any way.

The OP's original request was how to "disable" (i.e. tamper with) the speedometer.

aauummm · 01-13-2015, 02:47 PM

Quote:

Originally Posted by RVNewbie55

Does anyone know how to disable the speedometer from recording mileage on a 2006 GMC 3/4ton 4x4 Duramax while being flat towed?
Bob

Has your GMC ever had mileage accumulate on the odometer while being flat towed?

Gary RVRoamer · 01-13-2015, 02:49 PM

You shouldn't have to disconnect the speedo to stop miles from registering. I think you are doing your tow set-up wrong. Check the GM owner manual under Recreational Towing for correct key position, etc.

wa8yxm · 01-13-2015, 04:36 PM

Most vehicles made this century have electronic digital odometers, MOST of these get their operational power from the IGNITION lead,, so if the engine is not running, neither is the odometer.

Theory has it they might wire it hot all the time, in that case a fuse would need to be pulled,, but I know of no vehicle where that is the case save for some that have no "OFF" position.

GMC last I knew had ACC-LOCK-OFF-ON-START type ignition switches

Simply turning it to OFF does what you need.

To confirm

Note Millage displayed

Tow 10 miles

Check display again,, If same,, you got it.

RVNewbie55 · 01-13-2015, 04:51 PM

I have towed about 100 miles so far, and yes, it does record all miles even though the key is off;(no dash lights, etc.). To whomever said it is illegal to tamper, I do not intend to mess with the speedometer. If, however, I could find the correct fuse to remove I would do that. The owner's manual is clear about putting the Transfer case in Neutral, and the transmission in Park. They make no reference to the speedometer accumulating mileage. I've done many searches and can find a fuse to remove for more common toads, like Jeeps, but cannot find anything regarding my truck.

newmarpusher · 01-13-2015, 05:20 PM

Quote:

Originally Posted by RVNewbie55

...To whomever said it is illegal to tamper, I do not intend to mess with the speedometer. If, however, I could find the correct fuse to remove I would do that. ...

That was me.

I wasn't trying to preach federal laws. The only point I was trying to make was that because of tampering laws, the technology used in speedos makes it rather difficult (if not impossible) to simply disconnect them. On my old 1972 VW, I can just loosen the cable.