88 94 Chevy Bouncing Speedometer

[@loonauticus]

Nice Wesley! I had same issues a few years back with my 94 k1500, took me a month to find that! As these trucks get older, little gremlins like to start causing havoc. Now, my 98, I went through 4 clusters... But, not bad as it having 432,000 miles lol!!!

[@WesleyJohnsonMI]

Yes, all the 'known' issues are fixed. Now it's on to the weird electrical problems. Chaffed wires, bad grounds, pinched wires, etc. They're still stout & reliable trucks though. I've put 100,000 miles on this particular one in the last 3 years. I've never owned one of these past the 1993 model year, so I'm not as experienced with some of the late model nuances.

[@loonauticus]

@@WesleyJohnsonMI Bodywise is all the same, a lot of the wiring isnt much different, just the adapter ends and ports where they go to the newer style dash and door panels. Engine wise, most the wiring is close also, just depends on the motor and then when they put the Gen2 vortec engines, then the engine harness and ecm harness is different. the grounds on these need to be connected good, gremlins love shorted grounds. At least your nut hunting for grounds on the 6.5 diesels I have haha

[@ydocproductions5593]

Great fix Wesley! Chevy/GMC trucks seemed to have problems with there gauge clusters for a lot of years, wether it be speedometer or fuel gauges goin out. Thankfully it doesn’t take much time or money to get them fixed😀👍

[@WesleyJohnsonMI]

88-94 is typically just wiring issues. 95+ is when the actual cluster started to be a problem. 2000+ they started having major issues with the clusters. The 2000+ clusters you can actually send out to get the stepper motors fixed. The earlier ones you cannot. There's reasons why I drive what I have.

[@HODGEPODGEDODGEGARAGE]

Nice job with the fix Wesley 🙂👍 I'm sure it wasn't fun doing the temporary repair when it was 10° outside! 😬🥶

[@WesleyJohnsonMI]

No, no it wasn't. I'd drive over a bump & lose my hvac controls. Trying to get your frozen hands to work is an issue in itself! 😅

[@tjborba2003]

I have the same issue with my Speedo but my heating/ac controls work fine and I couldn’t find that plug u referred to

[@WesleyJohnsonMI]

What year is it? This is only good for the 88-94 trucks. It's buried pretty far under there, it may also be taped into the harness.

[@tjborba2003]

@@WesleyJohnsonMI it’s a 94 but I ended up finding it. Mine was located more towards the middle probably because I have a aftermarket stereo so they moved it however, I looked at the plug and it wasn’t burnt up so I think I am just going to go ahead and get a new cluster.

[@tjborba2003]

Also just like you said it was taped up

[@WesleyJohnsonMI]

@tjborba2004 clean the ground wires. There are 2 sets located on the thermostat housing bolts. One set is for the VSSB & the other set is for the instrument cluster ground. It may also come down to just having a bad Vehicle Speed Sensor.

[@tjborba2003]

@@WesleyJohnsonMI ok thanks a lot for the information

[@edwardmatherly280]

I have a 1993 GMC Sierra 2500. All my gauges go wild at times. When this is happening, the brake light comes on, and the heater stops, and there is a clicking noise. Also, if I over rev the engine, my guages go crazy. Any ideas?

[@WesleyJohnsonMI]

Bad grounds and/or a short. There's 2 grounds that attach to the thermostat housing. One is for the cluster, the other is for the speedometer. Clean all of your connections on the under hood power distribution block. Also, there should be a 10/8 gauge that goes to your starter solenoid. Make sure that connection is clean and that it hasn't melted to the manifold. Pretty much clean up every power & ground connection that you can find under hood. Fix anything that looks questionable. It's 31 years old and the electrical was just above marginal for these trucks, when they were new.

[@irishuwould5185]

My 94 the temp gauge and Speedo don’t work. The temp gauge stays at cold and the Speedo jumps around, also my odometer and trip meter turn very slow. Says I’ve only done a little over 2000 miles in a year when I’ve done many more. I’m thinking just buying a new cluster off eBay. I haven’t had any problems with my hvac.

[@WesleyJohnsonMI]

Before you buy a new cluster, there's several things that you can check. The temp sensor for the cluster is on the driver's side head. Check the ohms of the sensor to see if it's bad or not, replace as necessary. You should be able to find an ohm chart for it with a Google search. Next, check the 2 wires that are grounded to the passenger side of the thermostat housing. One is a ground for the speed sensor and the other should be a ground for the cluster. Lastly, check the plug that I pointed out in this video. It does like to melt/short out at this connection. Once you check all of these, if it still hasn't fixed your issue, check the connection at the speedometer sensor & pigtail. You may have to replace the speedometer sensor. If you have any more questions, just ask. I'll do my best to help.

[@irishuwould5185]

@@WesleyJohnsonMIcant find this particular plug in mine. Can you tell me what color wires they are?

[@WesleyJohnsonMI]

@IrishUwould the one behind the ashtray? It's 4 wires, red, black, Grey & tan. It might be taped to the harness, up high. Ashtray must be removed to gain access.

[@irishuwould5185]

@@WesleyJohnsonMI thank you sir

[@irishuwould5185]

@@WesleyJohnsonMI I found i am missing the ground at my thermostat. Idk if that will affect my Speedo or temo gauge. All other videos I’ve seen they have a ground thats between the two bolts at the housing. Looks as mine was cut. What does that go to and can I repair it?

[@williammclaughlin2606]

Been struggling to find why my Speedo doesn’t work on my 93’ I thought I narrowed it down to a Vssb. How did you determine it was the plug?

[@WesleyJohnsonMI]

That plug also has the cluster ground in it if I remember correctly. VSSB & speedometer sensors rarely go out, it's always a possibility regardless, but on 30ish year old vehicles, check the wiring first. Check for power input & continuity. Not to mention that I had already replaced my speedometer sensor & pigtail. No change in the way it functioned, so I dug into the wiring harness. It solved my issue.