Amp Gauge Blow Up

[patrickt]

You don't need to replace the burned wire, just snip it at both ends and run a new wire. The ammeter probably shorted out, via high resistance and too much current. That happens with ammeters and is why a lot of folks prefer voltmeters. The wire runs from the circuit breaker next to the starter solenoid over to the fuse box. I know you say it doesn't have a fuse in the #1 slot, but the hot side of the fuse is connected to the fuse below it. That's the charging path. If you look, you can see it. Just cut the wire at both ends, tape it off so it looks nice, and replace it with a straight shot of ten gauge wire from the circuit breaker to the #1 fuse position. Then you can just put a voltmeter in the dash. This is not a big deal.

[RICK LAKE]

Bliss, here's the problem, if you are running an Alt with 60amps or more and have a ampage draw with lights on, electric fuel pumps, blower for heater all running you are over the ampage the insolators on the amp gauge can handle and will melt. I went through the same thing and burnt the 2 wires and cooked the gauge. Do yourself a big favor. Replace the gauge with a voltage gauge from SW. It's black face and nobody will see the different unless you are looking for a 100% perfect cobra. Directly wire the 2 10gauge wires together and leave a pigtail to mount to the voltage gauge. You need a ground wire to the gauge and the light will pop into the new gauge. the new gauge also come with a light. Repair the other wires. I believe in the old days there was only a 37-42 amp charging system. Today we run from 60 to 100 amps depending on was acc you have in the car. I run a 95 amp system with dual fuel pumps, 3 cooling fans. 3 duct fans, ECU for FI system, power for the injectors, and other misc curcuits. Putting the same gauge back in the car will only over time cause the same failure. Make sure you either tape all the wires burnt, replace them or srink tube them and replaced the end connectors to get the tubing on. I used a heat gun at the low setting to get good melting and not damage coating on other wires. Good luck Rick L. After repair make sure the wiring doesn't get hot. You could have a short or rub at another location like behind the ALt. Make sure the Batt wire is not hitting or rubbing at or around the head area. Couple of guys have had this happen to their cars. I have a cover to protect this connection. God luck Rick L. Ps looking for another amp gauge, burnt and going cheap PS depending on how bad the wiring is and location, cut the harness taping back far enought to see good coating and replace wiring from there. Make sure depending on what connectors you use to solder the wire to the connectors. If you use butt connectors, get weather type ones and heat the ends to seal the connector. Also heat the center where the crimp is to melt the solder for a better connection. Don't let it catch on fire or melt the butt connector. Do you have a camera and could shot a couple of pictures to see the damage?? This would help with repairing it. This is not an ERA production failure, it's a gauge failure. Be happy it's not a total failure of the car as it melts to the ground. God was looking over you. Small easy repair. be happy could have been ALOT WORST. What number is your car?? I have 428. This was about the time Bob made some changes to the wiring system. I have an old wiring diagham on my car. I think the wires that burnt where white or yellow??We can fix it. Rick

[bliss]

Rick....(large pictures below)

It's ugly under there - especially now. Wires, other than those going directly to the AMPS Gauge were impacted - all the damage appears to be under the dash.

Yes, wires that burnt where white or yellow - but also a large black wire that comes directly from the AMPS Gauge (my brother informed me that that's a 'hot wire' - that's also the wire that ended up with no black coating at all (under the dash) - completely fried but it's OK on the firewall side.

Question - is a voltage gauge from SW wired in the same as an AMPS Gauge?

[DanEC]

Bliss - it's of little consolation but in all probability it's nothing ERA had any control over. Amp gages are just a risky deal. If you have been around awhile you may remember all those Mopars back in the 60s and 70s with the wavering amp gage in the standard dash. They ran all of the alternator current through that cheap gage and Mopar dash fires as a result have always been a problem. Throw a "Smiths" gage into the equation and now I'm kicking myself as to why I didn't have ERA substitute a voltmeter in my dash.

Unfortunately your burnt wiring is quite a bit worse than the one I had recently when my alternator connection wire got loose. I think you will at least have to pull the harness out enough to unwrap it sufficiently to inspect all wires next to the burnt one for damage.

If you can isolate which wires need replacing either due to being fried by the alternator gage and having the insulation fried by heat, ERA can fabricate just those wires for you and then you can place them in the harness and re-wrap it. Or an all new front harness is always an option.

I agree - it's a bummer.

[patrickt]

The purple wire looks a little dicey.... But I can't tell if that purple wire runs to an unused dead end or if it runs off to something else.

[bliss]

Thanks Patrick.

[patrickt]

Do you see how the left side of fuses #1 and #2 are joined together? Do you see the yellow and red wire both are soldered together on to the top screw to fuse #1? Yellow goes to the ignition switch and RED goes to the amp gauge (orange goes to the alternator). The red wire is what you want to snip along with the top lead to the circuit breaker. That red wire is fried up under the dash. This is really an easy fix, much easier than you think. And a voltmeter is just a simple two wire run.

[bliss]

Originally Posted by patrickt

Do you see how the left side of fuses #1 and #2 are joined together? Do you see the yellow and red wire both are soldered together on to the top screw to fuse #1? Yellow goes to the ignition switch and RED goes to the amp gauge (orange goes to the alternator). The red wire is what you want to snip along with the top lead to the circuit breaker. That red wire is fried up under the dash. This is really an easy fix, much easier than you think. And a voltmeter is just a simple two wire run.

Here's my fuse block set-up - as you can see, very old and a little scary looking to me. Notice that there isn't a fuse on the left side, first slot. The Cobra ran fine with no fuse in that slot - everything seemed to look OK.

[patrickt]

That "empty" fuse usually runs the fan. Your fan must be wired in and fused elsewhere. But look over on the left side and you can see that the hot sides of fuse one and fuse two are connected. That's the charging path. All THREE of those labeled wires are connected together. It also kind of looks like the connector between fuse one and fuse two looks a little melted, but maybe not. The red wire is the one that should run to your ammeter and from your ammeter to the circuit breaker, that is the last stop before the battery. The other two wires I have labeled for you. Now, I could always be wrong on this so check the actual wiring. You can look under the dash at the ignition switch pretty easily, and of course look at the alternator. You can replace that red wire that caused all the problems without having to actually remove it. Just cut it at both ends (fuse box and circuit breaker) and cut it out from under the dash as best you can, then tape it all off. When you drop the dash you'll be able see how that red wire goes to the ammeter. When it heated up, it may have damaged some other wires as well, but you'll be able to see that. If it looks really, really bad to you, then just send it up to ERA and they'll do it for you. But I think that if you replace that red wire, with a straight shot between the circuit breaker and fuse box, and then touch up any scorched wires under the dash, and put in a volt meter, you'll be fine.

[patrickt]

You can see why the prior owner pulled the fan fuse and, I'm guessing, ran a direct fused connection directly to the fan. There is evidence of heat damage from the fuse blowing, probably more than once, and he kept upping the amperage and it kept blowing. What is that little black necklace looking thing? Is it some kind of insulation buffer? And is the apparent melting on the connector between fuse 1 and fuse 2 just an optical illusion? I've never seen that guy even pucker before, much less melt. I'm guessing it's just a trick of the camera.

[bliss]

Originally Posted by patrickt

You can see why the prior owner pulled the fan fuse and, I'm guessing, ran a direct fused connection directly to the fan. There is evidence of heat damage from the fuse blowing, probably more than once, and he kept upping the amperage and it kept blowing. What is that little black necklace looking thing? Is it some kind of insulation buffer? And is the apparent melting on the connector between fuse 1 and fuse 2 just an optical illusion? I've never seen that guy even pucker before, much less melt. I'm guessing it's just a trick of the camera.

Black Necklace...
A closer look - it's some sort of crud that has built up on the end of the wire clip - looks a little baked on to me - probably tape, etc.

Between 1 and 2 fuse...
Looks like someone scraped something off.

I'm wondering if I should consider starting over - new harnesses, etc.

[patrickt]

Before I agreed with that, I'd like to see a couple of shots of whatever it is that's powering your fan and how the previous guy did it. That will tell you a lot.

[RICK LAKE]

Bliss you have my number, call me. Call ERA first and tell them you need a new fuse block. The rest is just time and doing 1 wire at a time. ERA will give you a wire diagram of the car with colors and gauge thickness. We do need to open up the harness and remove the clamp to see what other damage is done. SW has a black face gauge for cobras with a volt meter that goes to 16 volts. I think it is colored with red, yellow green. If you don't like the colors remove the clear cover and get black touchup paint and color over them. NO body will know but us. The reason the fuse block melted was the short was on the other side. The amp gauge terminal insolators got hard and just burn up. Beening there is not fuse from gauge to fuse block, it burnt those wires like you see. Voltage meter will fix this. If you played the game operation, this is a piece of cake, pie,beer, steak, candy.
Loosen the screw of the dash and drop the steering column. You will see how easy it is. When done just tape up the harness. What would you do if you where out in a desert, no AAA to help and no phone. You would fix the car. Play McGiuver and stop whining. this is part of owning a cobra. This How old?? That wiring has a better copper content than the new stuff. repair what you see. wrap the other wires by themselves. Rick L.

[patrickt]

Originally Posted by RICK LAKE

...fix the car. Play McGiuver and stop whining. this is part of owning a cobra.

Compared to replacing the turn signal stalk control on a Grand Prix, this is a piece of cake.

[bliss]

Originally Posted by RICK LAKE

Bliss you have my number, call me. Call ERA first and tell them you need a new fuse block. The rest is just time and doing 1 wire at a time. ERA will give you a wire diagram of the car with colors and gauge thickness. We do need to open up the harness and remove the clamp to see what other damage is done. SW has a black face gauge for cobras with a volt meter that goes to 16 volts. I think it is colored with red, yellow green. If you don't like the colors remove the clear cover and get black touchup paint and color over them. NO body will know but us. The reason the fuse block melted was the short was on the other side. The amp gauge terminal insolators got hard and just burn up. Beening there is not fuse from gauge to fuse block, it burnt those wires like you see. Voltage meter will fix this. If you played the game operation, this is a piece of cake, pie,beer, steak, candy.
Loosen the screw of the dash and drop the steering column. You will see how easy it is. When done just tape up the harness. What would you do if you where out in a desert, no AAA to help and no phone. You would fix the car. Play McGiuver and stop whining. this is part of owning a cobra. This How old?? That wiring has a better copper content than the new stuff. repair what you see. wrap the other wires by themselves. Rick L.

Unfortunately, I've lost practically all hearing so I no longer use the telephone.

Question....

1. What are the changes to the wiring, e.g. changing to a voltmeter (currently two wires go to the AMPS Gauge - with one directly from the Starter Solenoid)?

BTW - thanks so much for all your input.

[patrickt]

Originally Posted by bliss

Unfortunately, I've lost practically all hearing so I no longer use the telephone.

Question....

1. What are the changes to the wiring, e.g. changing to a voltmeter (currently two wires go to the AMPS Gauge - with one directly from the Starter Solenoid)?

BTW - thanks so much for all your input.

Unlike the ammeter, you can run a volt meter off of any switched power source (meaning it's only hot when the key is on). It draws virtually no current, so it does not have to be a beefy circuit. For instance, if you have a heater fan under there, the hot line feeding it could be easily tapped in to. If you have a cigarette lighter in the dash (that doesn't work when the key is off) that would be another nice spot to tap in to. Or you could just run a new wire out through the grommet and attach it the fused side of fuse #4, which is switched, IIRC.