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Hi all,

Today, it's raining buckets of rain down here in Louisiana. I was driving in it, and accidentally clew through some huge puddles. Shortly after I did that, and stopped at a red light, I noticed my speedo needle was jumping from 0 to somewhere around 10mph. It would kinda jump from 0 to 10 to 0 in a second or so. I did it a few times, but when I started driving again, it seemed to hold steady. I haven't checked it again while stopping, but I was a little confused and stumped by that. AFAIK, the 91's still had a mechanical speedo, so I shouldn't have electrical problems in that realm....any ideas?
 

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Bad ground?

CD, I have a similar intermittent bouncing speedo. It happens when I am at a stoplight and with my foot on the brake and the turn signal on, the speedo bounces. A wild guess on my part is that the engine to chassis groundstraps are missing, so the speedo cable is acting as the ground and the current is affecting the speedo. I haven't had time to replace the groundstraps, so this is just a theory at this point. Your puddle jumping may have caused a similar short. Have you noticed any difference when the turn signals are on?
 

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I havee a similar problem as well. It's especially noticeable with the A/C on.
Unplugged, for yours and mine, the problem seems to stem from the alternator not putting out enough juice at idle... mine bounces in time with the blinker occassionally. My chassis ground straps are in fine shape, so I don't think that's the cause. For you, CD, it might just be water in your speedo cable. My '77 Dodge did the same thing after going through puddles, and during cold weather, the speedo didn't work at all until the truck warmed up. Hope I've been a help.
 

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Discussion Starter · #4 ·
I'm guessing it was a combination of the problems you and unplugged stated. It doesn't do it at all anymore, so I guess accidentally getting a ton of water up there did something....
 

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Thanks, I'll get my alternator checked as well.:great:
 

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Thanks, I'll get my alternator checked as well.:great:
Your alternator may not be bad, but I've noticed when my A/C is on, the compressor causes the alternator to slow down enough at idle that it has issues running the electrical... My '93 is a Silverado, so everything is electrical:rolleyes: Glad to have been of help...:great:
 
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