blowing gauges fuse...please help

malletslinger · #1 01-10-2006, 01:52 AM

My Camaro is an 89 with the 2.8 V6. Several months ago I spent a weekend working on it...installed a new MAF sensor and a VATS by-pass, and gave my car a good, long overdue detailing.

From that weekend on, I have had an intermittent short that blows my gauges fuse.

Its been driving me nuts

...I have been trying to use the process of enimination to find the problem, but at first the problem didnt occur very often...but since I had to pull out my gauges to change the headlight switch, the problem has been happening within the first five minutes of driving after I change the fuse, so it is not so intermittent anymore...the car drives fine without the fuse, but if I turn on my headlights when the fuse is blown, I hear the ring noise non-stop...Im refering to the warning ring that you hear if you leave your headlights on and open the door. So I have been unable to stand driving at night.
I have looked many times, but dont see any obvious shorts like cut/exposed wires(I fixed all wire exposures months ago thinking that they may be the problem, but obviously they werent)
I have tried using my wiring diagrams in my Haynes manual to halp me find the problem, but to no avail...

I have owned this car for over four years, I have done all work myself, I used to say that no-one knows my car better than me...I hope I was wrong and that someone here knows what the problem could be.
Any advice, answers, ideas, or thoughts would be greatly appreciated.
Please dont be afraid to guess because my brain is fried, Im tired of guessing and being wrong

Thanks in advance

wrightz28 · #2 01-10-2006, 09:58 AM

Bum switch? It sounds as if you have short to power in it and over loading

malletslinger · #3 01-10-2006, 03:35 PM

What do you mean "bum switch"? Which switch are you talking about? headlight switch?
I know that I need to change the headlight switch...and this time I am going to buy a new one, this one was used and the dash dimmer doesnt work, but that isnt powered by the gauges fuse, is it???

malletslinger · #4 01-10-2006, 10:30 PM

Today I went through 4 fuses testing possible shorts, and was only electricuted once

Here is my list of items I have checked thus far:

headlight switch and pigtail
alternator and pigtail
my VATS by-pass
MAF sensor and pigtail
MAF sensor relay and pigtail
Oxygen sensor wire
Cluster/gauges and pigtails

So the short thats blowing the fuse isnt any of those.

Here are some of the observations I have made so far that may be relate to the short or may be coincidental...

The short always takes place between 2000 and 3000 RPMs
The short always happens slightly before, during, or just after the shift into third gear...(automatic trans)
I feel a slight hesitation when the short happens, but I think its because the computer looses contact with the MAF sensor when the short takes place, and then has to revert to defalt settings to compensate for the missing info...

Could it be the computer? Does the tranny use any electronic equipment or is it strictly mechanical? Am I loosing my mind? Sould I just pay a mechanic $90 an hour to look for the short? Will this ever end? Does anyone have any ideas?

wrightz28 · #5 01-11-2006, 11:17 AM

Sorry I'm not all that much of electrical guy, takes me a while myslef. Just this morning my VATS went nuts, shut the car off on me. Then whil checking underhood wiring, it went bonkers and locked the doors of course guess where the keys were? Shorted the damn thing out to get doors opened, ripped the module out, threw it on the ground, put it back in, everythings normal

Anyway, what about the gournds? If you remove them you should have circuit voltage at the tail end. The rpms are off the dizzy reference signal not the trans, which would only have the torque converter lock up switch and maybe a speed sensor on it, everything else is good ol vacuum.

malletslinger · #6 01-11-2006, 02:35 PM

Do you also have the vats mod from EcklersCamaro? Also, incase that happens again, I would recommend getting one of those magnitized key holders, putting a spare key in it, and finding a spot under your car to wedge it in(dont just rely on the magnet because it could fall off if you hit a big bump...guess how I know)

The best place to put it would be the toe-hitch support(if you have a hitch) if you get one with a good magnet, you can put it anywhere, provided that the magnet is facing down(towards the ground), that way, it is just the magnets job to make shure the box doesnt slip, rather than to hold up the weight of the key and box.

Apperently you know more about the electricle system then I do, what is the "dizzy reference signal"? Is that the little yellow box screwed to the back of the cluster with 3 wires running behind the speedo???

"Anyway, what about the gournds? If you remove them you should have circuit voltage at the tail end." Please explain what this means and its significance cause I dont understand

wrightz28 · #7 01-11-2006, 03:05 PM

off topis, the VATS problem this morning, not on my Camaro, it's down for the winter. This was on my daily dirver that a friend of my wife returned a favor by having her kid 'who's an electronics wiz" install an aftermarket system that's crapped out in one way shape or form since it was put in. AND, it's on a Buick which has it's own slew of electrical problems since birth, but wife wanted the remote start. Everything was dead so I didn't expect the locks to spring to life the way they did and shouldn't have.

NOW, on topic. Sorry, dizzy = distributer. There are 3 connectors on the HEI dizzy, the 4 pin connector, "BAT" on the left front, which is battery power to the coi, and the TACH reference on the front right. Chances are the terminal connector there may be loose.

Circuit voltage, meant battery voltage in most cases. Now, if you take the ground wire off, you should see battery voltage 12 or more (+/- no more than .5 v) because in a open circuit there is no amperage flow and voltage is constent across the entire circuit. The best way to find a short is to open the circuit at ech possible point starting at the ground until amps = 0. When the amperage stops, the short is found.

malletslinger · #8 01-11-2006, 05:52 PM

HEI dizzy? Are you refering to the unit under the cap and roter?
Where should I measure the voltage flow? The fust or the conecters where I remove components?
...but wait, the short isnt constant, it only happens when Im driving, never when Im stoped, at idle, reverse, etc...The fuse doesnt blow when I put it in, it is fine until after I start driving...so how would I be able to find the short if it isnt constant? I dont see how this method would work in this case...or mabe Im just confused

wrightz28 · #9 01-12-2006, 10:24 AM

HEI (high energy ignition) is the distributer's name in it's entirety.

I would be inclined to disconnect the tach wire on the side of the cap, the connector I was talking about. You mentioned it happened (the short) at so many RPMs, but I must have missed the association it must be driven to do so. Maybe that might help narrow things down?

malletslinger · #10 01-12-2006, 11:50 AM

I will try that this evening...

wrightz28 · #11 01-13-2006, 10:14 AM

So what happened?

malletslinger · #12 01-13-2006, 01:53 PM

Yesterday was a busy day for me...lotz of stuff to do, including getting another box of 10amp fuses...
Im about to run to the bank now, but when I get home, I intend to divote todays house of daylight to this problem, and your suggestion will be the first thing I try.

So I just unplug that pigtail, test drive, and if the fuse doesnt blow then that means what? that I need a new distributer? That would suck, but at least I would know what the problem is.

wrightz28 · #13 01-13-2006, 02:16 PM

I would be inclined to look for corrosion or chaffing on the wiring, burns. a physical short would be a beutiful thing, easy to find, easy to fix. Especially since you have 12v sitting right there at the other side of the terminal.

An internal short (failed coil or something - example only, not saying it is!) would suck cause you'd have to find it.

malletslinger · #14 01-13-2006, 02:18 PM

finding it would not be a problem...my uncle owns a salvage yard, which has come in useful many times

malletslinger · #15 01-13-2006, 03:31 PM

There were two bats on the passenger side of the dizzy, the one on the left had two wires comeing from it that go to the coil. The one on right had 3 or 4 and I could not see where they go, so I disconnected the one on the right, but the car wouldnt start so I reconnected it and made shure both bats were on tight, tried to test and the fuse did blow again, but it was a bit longer after the shift into third than usual and I would sware I heard a "tick" when the fuse went...never heard/noticed that sound when the fuse blew previously.
Seemed to origionate somewhere in the dash. What could it be? One of the needles on the gauges slapping down after the short, the sound of the fuse blowing, or a relay perhaps?

I know its wishful thinking but I hope it was a relay in the dash(or mabe on the firewall just infront of the dash on the drivers side?).
If it was a relay, then that could be the cause of the problem because I dont think any relays are suposed to beguin opperation at that time, at least not any in the dash. Air conditioning, headlights, and radeo were all off, so it couldnt have been a relay for one of them, right?

So what do you think? Did I try to disconnect the wrong bat, or could I be on to something with the relay idea?

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