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Discussion Starter · #1 ·
some of my gauges keep turning on and off for no reason while driving (oil pressure, trans temp, gas gauge, engine temp) the speedo, tach and volt meter stay working but when the gauges turn off ac compressor shut off so i have no ac. before the gauges cut off the security light comes on followed by the battery light then the gauges turn off. i replaced the gauge cluster but it still does the same thing. also checked for a bad ground and found nothing. any ideas of what it could be? its an 2003 single cab chevy 4.8 work truck roll up windows manual locks with a lq9 :help:
 

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Discussion Starter · #3 ·
yea i know they had a recall on the gauges but this is something other than the gauges because i replaced the gauges and it does the same thing
 

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yea i know they had a recall on the gauges but this is something other than the gauges because i replaced the gauges and it does the same thing
No. cluster shits the bed ALL the time.
 

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sounds like it could be something in the engine wiring harness :imo probably acquired while swapping the engine. could be a possibility that a ground wire is grounded to the wrong location or wiring harness is shorted out somewhere.
 

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Discussion Starter · #7 ·
hmm thanks coop yea i have been looking for a bad ground and found one but it just made my volt meter read higher so im still looking for another ground or faulty wire
 

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FWIW, I blew an ignition fuse a while back swapping in my trans. It made my gas needle do this:jester: Also, if the grounds are in the improper place, components grounded through that ground may malfunction. Seeing how you've replaced the cluster and still have a problem, it leads me to believe its a short. Also, check all injector/fuel pump wiring. I don't know if they spliced anything for an inline fuel pump back when nick had the procharger on that truck. Another start would be to check the actual PCM and PCM wiring. The data is sent via the Class 2 Bus to the PCM then to the Cluster.
 

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Discussion Starter · #9 ·
anyone know where i can find a diagram of where all the wires are supposed to be grounded?
 

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your best bet is to probably go to the part store and buy one of those manuals for our trucks i bet there is something in there about it....
 

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Discussion Starter · #11 ·
yea might do that took the dash off yesterday and didn't find anything. but i did find out that if i would move the gear shifter up and down it would turn the gauges back on then they will go back off so i think it is something in the column or on the trans.
 

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I doubt that something in the prndl would directly effect guages. you'll want to go to where they get their information from (pcm), or check out whats going on in the column. Does it have an autostart or security system?
 

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Discussion Starter · #13 ·
no autostart or security
 

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Discussion Starter · #15 ·
whats a pnss?
 

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Discussion Starter · #18 ·
gauges are working correct now after i was driving down the road and it down shifted by itself for no reason. now gauges stay on when they are supposed to. what controls down shifting ecu?
 

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Discussion Starter · #20 ·
got them fixed finally ended up replacing the pnss and found a ground loose on the drivers side cab body mount. thanks for all the help everyone!!!
 
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