2000 GMC Sonoma Dead battery/Instrument Cluster

WILLIEWILSON55

MEMBER
2000 GMC SONOMA
4 CYL
2WD
MANUAL
81,000 MILES

It all started with a dead battery, I then replaced the battery and followed by the alternator. This stopped the dead battery for a day then it needed to be jumped everytime it was started. Thats when schucks told me I had a battery draw. After pulling fuses I found out that the instrument cluster was pulling.8 amps plugged in and.1 (normal) unplugged from the gauges. I then bought a used instrument cluster from the junk yard and installed it. The new instrument cluster was fine although my stereo stopped working. After driving the truck for a couple of days I thought id try to plug my stereo back in this is when the backlights on the instrument cluster stopped working. I then took the new instrument cluster back because I thought it was shorted out, I got a new one and found out there wasnt a short because the new instrument cluster's backlights weren't working either. Then I looked at the fuses and found that the RDO IGN fuse was blown. After replacing that fuse my radio nor the backlights on the instrument cluster still will not work. Thats where im at right now, any help is greatly appreciated. Thanx.

2 Replies

ROBBIET

MEMBER
8 POSTS

I have a 2000 Gmc Sonoma Extended cab 4WD and have had similar Problems with the battery being drained and I also found that the current draw from the instrument cluster (Location 19-The 'RDO/BATT' Circuit, which is fused at 15 amps), was.8 amps when the instrument cluster is plugged in and close to.1 amp when it is unplugged. I just started diagnosing my problem a few days ago and am not finished figuring it out yet. I also have eratic fuel gauge readings which are not correct to the actual fuel level in the tank. From my research it seems likely that my fuel level sending unit (located in the gas tank) is to blame for the eratic and incorrect fuel gauge readings. Apparently there is a resistor on the sending unit the fouls up or gets wrecked in some way from something in the gasoline. My next step is to unplug the connectors from the sending unit (hopefully I can reach up onto the top off the tank to reach the connectors), and then do a reading to see what the current draw is with the instrument cluster plugged in but the sending unit connector unplugged. If the current draw drops to the normal.1 amp, then I would think this means that the sending unit is to blame for the excess current draw, and not the fuel gauge, or, any other guage for that matter in the instrument cluster. I'll let you know what I find out as I progress.

Apparently the whole sending unit has to be replaced
and not just the one part. I won't know for sure until I drop the tank and take it out to see what it looks like. Often times people replace entire things because that's what the parts guys and other people say has to be done, but i've found that I can often do otherwise with some patience and ingenuity in taking stuff apart and 'rebuilding' it in a sense. For far less than to replace the entire device.

Do you have fuel guage problems as well?