So There are probably a dozen threads on this subject but zero answers. The other night my gauge fuse blew while driving home and the headlight buzzer stays on when the lights are on. This seems to be a common problem but it has zero answers. On YouTube there are a few thirdgen owners with the same problem but no one has found a solution. I have found threads going back to 2008 and not a single one has an answer. Someone out there has had to have found a reason for this and a fix right? Any solutions would help.

 

You have a short.

Get the wiring diagrams (they are posted on these boards) and start tracing circuits related to ignition in 'RUN"

 

Which wiring diagram do I use? There is one for the steering column, one for the ignition system, etc. How do I know which one to use?

 

You need the diagrams that show the wiring for the circuit thats blowing.

You said the gauges are blowing. What exactly is blowing. Guage lights, guages themselves...etc. They are powered by different things.

There is something in that circuit that is shorted. So you find the fuse that is blowing, then you start investigating connected circuits.

 

It's the gauges themselves. Only the speedo works since I know that uses the speedo cable. The gauges themselves stop working and the headlight buzzer stays on. It seems to be a common problem as there are dozens of threads going back to at least 2008 but not one has a solution. Every thread seems to end with "Anybody" or "I have the same problem did you ever find a solution?"

On another car forum a guy said he just installed mechanical gauges and disabled his headlight buzzer because he couldn't find the problem.

 

Unfortunately, things like this usually don't get solved unless you're under the dash finding the problem. But first step is to find and UNDERSTAND the wiring diagram for the fuse that is blowing. That narrows down the possibilities to a subset of wires. Anybody here also would have to look at the wiring diagrams to help answer your question.

It is best if you can find a wiring diagram from a real Helms manual because it will show all the wiring on a particular fuse. If you can't find that then you can look at the crummy diagrams in a Chilton manual and maybe piece together the story. Austin thirdgen has the Chilton style diagrams, http://www.austinthirdgen.org/index.php?pid=45

 

Well. It’s time to start reading diagrams if you want it solved. You are the one with the problem and have access to the broken setup.

a fuse only blows when some device that has power flowing through that circuit is drawing more amps than its allowed to.

You need to start tracing and isolating circuits. You need a VOM, and the diagrams.

you are asking someone to tell you an answer to a question with too many variables that could be the cause.

Seriously, electrical diagrams aren’t that hard to read. the most likely cause of a short is a pinched wire or burnt out electronic device.

 

Look at the upper right of this wiring diagram and you'll see the Gages fuse powers the audio alarm. The alarm buzzes when there is a path to ground, so you're likely looking for a problem that allows the audio alarm to be grounded. This is why I hate the Chilton diagrams though because I can't really understand how things are wired in audio assembly. Really wish a diagram could be found from a GM Service manual.

http://austinthirdgen.org/mkportal/m...ody_wiring.gif

 

What kind of alarm is sounding? That might narrow down the problem. I looked at my GM Service manual for '88 Firebird because I figure the alarm has to be similar to your '86 Camaro. The alarms described for '88 Firebird are,

* Fast pulse chime (lights on)
* Fast chime (key warning)
* Slow chime (seatbelt warning)

So that explains a little bit how the audio alarm works. The different ground paths to different devices result in different chime sounds.

 

Lights on.

 

All you need to do is find the wiring diagram for the gages fuse in the GM service manual. Then determine which wire down range of the fuse is shorted to ground. Those generic wiring diagrams are just about useless.

Edit : 1987 Camaro diagram, should be close to the same but probably slightly different. Somewhere that pink/blk is shorted to ground or otherwise drawing too much current through the fuse.

 

Okay, that solves the mystery why the audio alarm sounds. It's simply because voltage is lost when the Gages fuse blows. The audio alarm interprets that as key switch being in off position, and sounds the alarm that you left your lights on.

The Gages fuse also powers pretty much all the lights and gages in your dash, and other devices that Drew shows. The short circuit is somewhere in there. The alarm sounding has nothing to do with the cause of the problem, it's just a secondary outcome.

 

Correct, but the gages fuse provides keyed voltage to circuits all throughout the car. "Gages" is a generic label, it could as easily be a disconnected AIR diverter valve connector melted to an exhaust manifold as something in the gauge cluster. Unfortunately the name of the game is eliminating possibilities to narrow the problem down to the minimum causes. That's going to take time and effort.

 

I tried unplugging some of those parts and threw in a new fuse to see what happens. Still pops.

I'm not sure where some of those parts even are. I've tried googling for no results. Mainly the Light Driver Module, Throttle Kicker Relay, Electronic Regulator Value, Air Select Valve and the AC Compressor Control Relay (is that next to the Low Pressure switch on the passenger side)?

 

Light driver module is just kinda hanging out in the console; usually a greenish plastic box about the size of a deck of playing cards. It drives the CEL.

Throttle kicker relay is on the driver's side of the carb. in carbed cars.

AIR Select valve is part of the AIR diverter valve. In front of the pass side head, below the alt.

Note that the left-hand half of that bottom row on Drew's FSM schematic applies to V8 cars, the right-hand half to 6-cyl ones. Ignore all the stuff that doesn't apply to your car.

Pretty sure both the Electronic Regulator Valve is part of the AIR diverter valve. Not positive though, it's part of the 6-cyl eqpt, of which I have no knowledge unless it's also applicable to V8.

No idea where the AC Compressor Control Relay is. It's specific to 6-cyl.

Nobody is going to be able to tell you where a short is. Every one is different. It could be a chafed wire, an unplugged connector hanging somewhere and touching something, a bad component, "custom" wiring gone wrong, etc. etc. etc. YOU have to find it. It's not like every car has the same bare wire in the same place. Although in some cars there are places that are prone to it, such as where harnesses are routed in places that turn out to be risky, over time. I know of no such places in these cars though, that apply to that circuit.

I hate to tell people to cut wires, but sometimes that's the only way to track down a short. For example you could cut the wire between C207 (a connector pin, at the ECM if memory serves) and S175 (a splice, that's under the hood... the wire is in the ECM harness), and if the problem clears up, you know it's something downstream of that point. If you go that route, make sure you cut in a place that's accessible and easy to make a GOOD SOLID repair to afterwards; NOT just use a wire nut for example.

 

Step 1; Disconnect / Remove the Audio Alarm and try a good fuse. Weird things can happen when an Audio Alarm 'craps out'. Here is a schematic of the Audio Alarm:





If your car is an 86 TPI than it has none of this equipment. Here is another schematic that *might* help: It's from an 85, but IIRC the Power Distribution in 86 was the same for TPI.




Disconnect C207 ( 2 "paired" connectors,.... dash harness-to-ECM harness connection under the pass side of the dash) and see if the short still occurs. If it the fuse still blows out than it can only be caused by something in the interior of the car. If the fuse remains intact than something under the hood is causing it. (wiring or plug, at or to the: canister purge, EGR solenoid, Air Diverter, or Canister purge. )

Here's what C207 looks like:
https://www.thirdgen.org/forums/elec...ing-plugs.html

Here's where it's located:
https://www.thirdgen.org/forums/elec...gram-c207.html

 

Finally getting back to this problem after a month. My rear end was shot and needed a full rebuild. Turns out my car has a 9-bolt 7.75 inch rear end with 3.70 gears. A pretty rare combo that is originally Australian. So it made parts harder to find.

The fuse is still popping and I am going to unplug C207 tomorrow (I'm assuming it's under the passenger side dash?)

I found this diagram after doing some googling that may be of a better help.

 

There's a kin to a picture of the C207 in my post above so you know what it looks like.

Don't use that diagram you just posted,..... follow the diagram that Drew posted for you. The 86 & 87 cars are far more closely "related" when it comes to wiring than an 82-83. ( there were a LOT of changes made after 83. ) Besides: car is a TPI and that other diagram HAD to be from a Carb car & it's best to follow diagrams that best matches the engine / induction of the car your workin' on.

The 87 diagram he posted also shows everything on the GAUGES circuit, not just the Brake and VSS. The other diagram to focus on is the page 106 diagram I posted above; That one follows power/voltage from the battery source at the starter,...... all the way to the gauge fuse --> where Drews' diagrams continues on from there.

Here is the wiring "map" to your C207 connector:

Good Luck !!

 

I have this exact same problem still and im absolutely baffled idk whats causing it