My HVAC lights and cluster stopped working a while back, and I am about to start tracking the problem down. Being a relative newbie to the electrical aspect, what is the best tool to use to trace a short or a loose or disconnected wire? Test light? Multimeter? Something else?

Also, plain and simple, how do I use it and how will I know if I've found the problem? I guess I understand the basics of current, but now how to test for problems with it. Thanks for any help guys and gals.

 

The best tool is a good quality wiring diagram. It might be worth it to get the genuine GM diagram from a GM service manual. After that, a continuity tester / volt meter.

You troubleshoot by first looking at the components that have quit working. Statistics say that there is probably only one problem that is common to all the malfunctions. Your HVAC is down and your instrument cluster is also down? Is all of it down or does some part of it still work? Look at the wiring diagram first and try to find a common circuit: It might be a common fuse, or a common connector. A common ground circuit or fusible link. Use the wiring diagram t oidentify all commalities of the failed components, then search out those connectors and look for voltage on both sides of the connector. If one side of a connector has 12 volts and the other side of the connector has 0 volts on the same wire, then that will be where the problem lies.

 

AKA, a multimeter.

 

Here's where I've gotten without any testing equipment. I THINK I've got it narrowed down to one wire, but you never know with electrical stuff. That's why I wanted to be sure how to use the tools before I dig in.

The dash lights are controlled by Pwr Accy fuse #7. Also run off this fuse is the radio, theft deterrant relay, rear hatch release relay, side mirror adjustment switch, and shock sensor.

Everything works except for the dash lights, so it's not the fuse or the wires running from it to S211. It pretty much has to be the connection from S211 to the guages unless all the lights simultaneously went out (very unlikely). Does that make sense?

Another concern I have is that the BCM was fried for a while, and it kept shorting out my radio until I replaced it. Do you think it may have done damage to other things connected to the same fuse circuit?

The schematic I'm using is from this thread:

https://www.camaroz28.com/forums/sho...d.php?t=516704

Now my question becomes, what is S211 on this schematic, and how do I get back there to it to diagnose it? Do I have to take the dash off? Thanks for sticking through my ramblings.

 

Hey Z28SORR, How are things in Friendswood? That's actually where I bought my car. Do you happen to know a guy who used to be a Chevy mechanic who drove a white 97 Z28 back in 99-2000? I think he had red hair, but not sure. Big block hood. Don't remember his name though.

 

The "S" in S211 stands for "slice". It can literally be wires sliced together at that point or it could be a stud where all these wires are connected. The factory wiring diagrams show you where these slices are physically located. I will look at mine tonight.

IT'S COLD!!! Sorry I'm a little old to be "hanging out". And I do all my own work so don't know him. Very possible I've seen the car though, I do go to the track(HRP) from time to time.

 

Thanks for the info and for anything you can find in your diagrams. I just don't want to have to pull the dash off to get to this.

Does anybody know a way I can test the circuit board on the back of the gauges? Maybe something there fried.

As for hanging out, you're never too old to hang out. It's just finding the right people to hang out with. I personally have stopped going to meets and stuff because they seem to be overrun with 16 year olds in lime green civics with huge wings who think it's cool to go 60 through a parking lot. Well, that and the fact that my car has been down for a year! LOL.

 

Sorry for the late response but I've been out with a cold. Anyway your sig. indicates that your driving a 97 Z28. The diagram your refering to is NOT for a 97 Z28, so the "S211" component is wrong.
You stated that "My HVAC lights and cluster stopped working a while back". I don't know that you mean by "cluster"?
If the only problem is the HVAC Control Assembly lights Then this will be fairly easy as this is a single ciruit.
It is a .35 GRY wire(22 gage) coming from S224 (part of the #8 circuit) and going to Connector C3, Pin A, on the back of the HVAC Control Assembly, to the lights. It exits through the same connector C3, Pin B, via a .35 BLK wire(22 gage) going to S216 (part of the 650 circuit), to ground.
If all your other lights are working it has to be in this circuit/wire! The most likely spot would be the connector C3 on the back of your HVAC Control Assembly. Unfortunately the book does not show the exact location of the S224 & S216 slices. Only that they are "Within instrument panel area".
Good Luck,
John

 

Thanks John. I hope you are feeling better. This should help me some. As far a "cluster", I was referring to the backlighting on my guages in the dash (tach, speedo, etc.). All of them went out at the same time. I turned on my car one night, and pop, all went out. Fuses were checked and none are blown.

Are the 95 and 97 instrument cluster connections the same? If so, it looks like the problem can be traced from C3 (I/P Illumination) and C4 (Ground) according to this schematic:

http://shbox.com/1/95_z_cluster_pinout.jpg Does that sound right? And wherever these meet in circuit with the HVAC lighting should be the issue, right?

 

No! 93-95 look the same, but they changed in 97. 97-02 look the same.
If ALL your gage lights went out at the same time, that is entirely different. You will have to check 3 fuses in the I/P(instrument panel) Fuse Block. The GAGES FUSE 9(10amp), TAIL LTS FUSE 5(20 amp), and the I/P DIMMER FUSE 16(5Amp) fuses.
The reason for this is that the gage lights(or I/P lights) are feed by two different circuits. One is through the DLR(daytime running lamps) module and the other is through the headlight switch.
After checking that these fuses are ok. Turn the ign. to ON. Turn the Headlamp Switch to ON. Run the I/P Dimmer Switch to MAX and see if the I/P lights are on??? If they come ON the problem is in the DRL Module/circuit.