Gauges not working

[adrian_lee572]

I have an '84 K10 that i recently purchased, but like all trucks that are use it has a few bugs that need worked out.  First of all the blinkers weren't working so i replaced the turn signal/hazard switch and also the wiper switch.  That fixed all the problems there.  Second my gauges aren't working.  When i start the truck none of the gauges move except for the fuel.  It moves towards empty but rolls right past it.  Do i have a bad gauge cluster or could it be more than that.  The other problems that i am having are that the horn/dm fuse keeps blowing and my dome light is working when the door switches and closed (door closed).  This is very frustrating because the dome light is coming on with the door closed and shutting off when the door is opened.  The courtesy light under the dash is coming on and going off when it is supposed to.  Any insight will be gladly appreciated.  Thanks

[DnStClr]

Wow. No gauges working- did the previous owner tell you about that? You will have to remove the instrument bezel and cluster to do some checking. Do you have a multimeter to check for 12 v dc ? Or do you have a tester light? It does the same thing- lights up when it senses voltage..
When you remove the cluster, make sure that the electrical connector is fully connected before checking anything else. On the back of the instruments there are wire prongs that give the signal for the gauge to work. One of them brings 12 volts to the gauge and you can check to  see if the 12 volts is there using the tester. For simplicity, go to AutoZone or another car parts store and buy one.


The pointed end of the tester is touched to the 12 volt signal and the other end- the wire- is put on a ground, so that any signal going to the tester lights up the light. Either way you do it- with a multimeter or tester light- you must 1st turn on the ignition and then test for voltage at one of the prongs that hold the gauge. If you get voltage, the gauge is bad or you have a bad ground connection for the circuit. You'll see that on the rear of the instrument cluster that there is a printed circuit board. The circuit board carries the voltage signals for the instruments and lights, and returns the signals to ground. If a grounding circuit on the board is bad it an affect the gauges.
To determine which circuits control which signals, you really should have a wiring diagram for your truck.  This will be a good bit of work and you have to be careful with your tests .
just take your time and check for voltages and good grounds.