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[skidderman]

The speedometer quit working on my truck. So far am throwing good money after bad with zero luck. Can any of you recommend someone in the Edmonton area that would be best to take this to? Your ideas & help would be most appreciated.

[jstubbs]

What year and model of truck? If newer and it's a highly electrical problem, I'd say bite the bullet and take it into a dealer as it could be any number of issues. If older (i.e. 2007ish and older), I'd recommend OK Tire on 82nd ave between 75th and 50th street. Couple smart mechanics there who are pretty good with the electrical end.

(Oh, and BTW if your truck is a mid 2000s Sierra/Silverado, good chance it's just the stepper motor on the tach died. Buddy in his 04 Sierra had it happen to him, watched a quick YouTube video, ordered a stepper motor, installed it in an afternoon no problem).

[skidderman]

1998 GMC K3500 with 454, auto transmission with gear vendors overdrive. 137 original kms. Everything else works except the speedo. $600 into so far and all I am doing is throwing money at it.

[Manning74]

Could be a broken wire off of the speed sensor, top of the t case, had this issue with an 03 not sure if its the same set up tho

[silverdoctor]

Originally Posted by Manning74

Could be a broken wire off of the speed sensor, top of the t case, had this issue with an 03 not sure if its the same set up tho

Yep. pull the speed sensor - could be wiring or the plastic gear.

[skidderman]

Originally Posted by silverdoctor

Yep. pull the speed sensor - could be wiring or the plastic gear.

If it is the plastic gear does one have to pull the transfer case apart?

[silverdoctor]

Originally Posted by skidderman

If it is the plastic gear does one have to pull the transfer case apart?

Doesn't look like yours has a gear, sorry, could just be the cable. Trace the speedo cable to the transmission, there should be a cap to unscrew.

[skidderman]

Sorry mine is all electronic.

[sako1]

Vss (vehicle speed sensor ) is quite common on those trucks. Very rarely the reluctor ring in the tcase will crack or loosen off. Is the transmission shifting properly? Many times if the speedo isn't working the truck won't shift properly. I have found the most common problem is either the Vss or the wiring from it to the pcm. Those clusters pop out In just a few minutes. Might be worth a try swapping it with a buddies of approx the same vintage.

[silverdoctor]

Originally Posted by skidderman

Sorry mine is all electronic.

Sorry, misread your post, my bad. Speed sensor is probably the best bet.

[skidderman]

Originally Posted by sako1

Vss (vehicle speed sensor ) is quite common on those trucks. Very rarely the reluctor ring in the tcase will crack or loosen off. Is the transmission shifting properly? Many times if the speedo isn't working the truck won't shift properly. I have found the most common problem is either the Vss or the wiring from it to the pcm. Those clusters pop out In just a few minutes. Might be worth a try swapping it with a buddies of approx the same vintage.

Truck shifts perfectly except that I can't engage the gear vendors overdrive because it will not kick in until 70 or so Kms an hr. Am currently using my gps to get a speed & if you were not looking at the speedo you would think nothing is wrong. One other person said it could possibly be the alternator. I did notice recently that when the signal lights are on the alternator gauge flexes slightly as the signal turns off & on. I only noticed that very recently. Maybe that is normal. Don't know.

[sako1]

Originally Posted by skidderman

Truck shifts perfectly except that I can't engage the gear vendors overdrive because it will not kick in until 70 or so Kms an hr. Am currently using my gps to get a speed & if you were not looking at the speedo you would think nothing is wrong. One other person said it could possibly be the alternator. I did notice recently that when the signal lights are on the alternator gauge flexes slightly as the signal turns off & on. I only noticed that very recently. Maybe that is normal. Don't know.

Quite normal for the gauge to flicker back and forth while signaling on those trucks. What parts have you replaced?

[Calgarybowhunter]

You likely have a stepper motor failed. They control the gauges on GM's of that vintage. They are on the circuit board behind the speedometer.
Not to bad to replace if you have some soldering skills. They are pretty inexpensive on eBay etc.
I replaced a few on my wife's car when the gauges failed.

Good Luck

[skidderman]

Originally Posted by Calgarybowhunter

You likely have a stepper motor failed. They control the gauges on GM's of that vintage. They are on the circuit board behind the speedometer.
Not to bad to replace if you have some soldering skills. They are pretty inexpensive on eBay etc.
I replaced a few on my wife's car when the gauges failed.

Good Luck

From phone calls & asking questions I don't think there are stepper motors on this year of truck. I called a place in Edm that fixes instrument clusters & he said there was no use taking this one in because he said they don't fail. Thinking of getting a cluster from the wreckers to verify one way or the other. If there are stepper motors on this please set me straight. It's difficult throwing money at this because nothing so far can be pinpointed so I keep spending money & am running out of hope to get it repaired.

[skidderman]

Originally Posted by sako1

Quite normal for the gauge to flicker back and forth while signaling on those trucks. What parts have you replaced?

Replaced the OEM speed sensor.
Found a used speed sensor for the gear vendors & replaced that. Gear Vendors wants $230 usd for a new one. Would buy it if I knew for sure but I don't. Gear vendors said they rarely see those sensors fail but it is possible.
Checked gear vendors wiring & can see nothing obvious. Am getting power to it.
Mechanic got a ABS code for right front wheel so replaced the bearing.

ABS light is still on the dash
Speedo jumps slightly when starting then falls back to zero
Instrument cluster says check gauges when I start then goes off

So far I've spent over $600 & got no where. Very, very frustrated but appreciate the advice I am getting.

[Calgarybowhunter]

Had a quick look on-line, looks like you are correct. To bad, it would have been an easy fix.

[tri777]

I'd pull the dash cluster off and see if any
connections behind it isn't clicked in properly/etc.

[urban rednek]

Take a minute to go read this thread on the GM Trucks forum, not exactly as you described, but close enough to be worth a look:
http://www.gm-trucks.com/forums/topi...peedoshifting/

This is a copy & paste of the last post on that link, from 2012. It's what caught my attention, because you just never know what the manufacturers' engineers were thinking when they design these things:
I had something similar on my 4.3L Sierra with a 4L60e transmission. I had the transmission rebuilt and soon after started getting codes that didn't make any sense. It was shifting through all the gears but the timing of the shifts seemed off. It just didn't feel right. I started tracing through the speedometer sensor wiring and that wire goes through the brake light switch at the pedal to a jumper block (I forget what it is called) that sets the shift points according to the rear end gear ratio. Since the transmission was just rebuilt and a really good shop did the work I didn't think it was the sensor. The other stuff I was looking at replacing was a couple of different parts at ~$200 each. The brake light switch was $12. So I replaced the cheapest part first and that was the problem. ~200K miles with maybe half of that in city driving so I can understand the brake light switch wearing out. It seemed weird that the speed sensor was routed through the stop light switch but that's the way it is.
I know it's a different truck but it might be worth looking into just to see if your speed sensor circuit goes through the brake light switch.

Good Luck.