Coolant temp and gas gauge not working after battery connect.
 

I installed an OEM Aux cable today in my 2005 4.8is. Upon reconnecting everything and reconnecting the negative terminal on the battery, everything seemed to work fine. I took it for a test spin and noticed that my gas gauge was on "E" and coolant temp was all the way to the far left. Low gas warning light comes on (bright yellow). After a few miles, they still didn't work. I checked fuse 1, 43, 45 and they seem fine. Have the batter disconnected and will reconnect in a few mins. Any ideas as to how to get these gauges working again? Do I need to calibrate them somehow?

Thanks in advance!

P.S. everything was working fine before and I have a full tank of gas.

Reconnected battery... Didn't fix anything. Did needle sweep and the needles moved, but didn't fix anything. I have the car in a trickle, but battery was green-eyed. Any other things I should try?

Try to do this way:
1. Turning car off
2. Taking out fuses for Instrument Cluster - they were 1, 43, 45
3. Turning ignition to position 2. You can try and crank it, but mine wouldn't turn over.
4. Turn car off
5. Reinsert fuses from step 2.
6. All functions are reactivated.

Did the above and now my coolant gauge works, but none of the text on the gauge cluster is appearing.No total miles, range, information, etc.

update: odometer, trip info, and letters are appearing on gauge cluster.! Just took around 5 miles.

However, the fuel gauge is still not working and the coolant temp has stopped working. Back to square one.

Alright, this is too weird. After the car has gone into hibernation and is started, coolant temp gauge works, but fuel does not as well as odometer, trip odometer, temp, and the obc. After 5 miles of driving, the odometer, trip odo., temp and obc start to work, but the coolant temp gauge falls to the far left. I'm at a loss of ideas.... Any help would be greatly appreciated!

Curious is "needle sweep" one of the OBC test functions?

It's under the secret menu under test 2. Hold down the gauge button on the right, then turn car to pos. 2. Test no.1 should appear. Use trip odometer reset to select test no. 2. I thought this calibrated the cluster.

However, I can only do this once the odometer, trip odo., temp and the rest of the OBC stuff works. I am going to replace fuses 1, 7, 43, 45 when I get time.

Replaced fuses 1, 7, 43, 45 using method above and no dice. Disconnected Aux and nothing happened. Now trickling the battery again and will disconnect tomorrow evening for a couple of hours....

Could it be a module gone bad? What/ which modules are responsible for coolant/fuel gauge, iF any?

Should I take out the gauge cluster and see if possibly the plug is loose (never been taken out).

Your IHKA (Instrument Cluster) module may be on the way out? If you have access to DIS/ PA soft or Car Soft... diagnostic software, you'll be able to check for errors and clear them if any for your cluster. Start up and if any of the issues remain, the software will tell if you have a communication problem with a specific module.

Good Luck!