electrical help needed

[Canoe]

Here's part of what is difficult trying to diagnose something long distance.
You state "the only damage visible was near stereo", but don't say precisely what that was. We're left assuming what you stated before.
You've stated you don't have much experience with electrical, yet feel confident to state there was no damage inside of dash, where we had enough heat to melt some wires (although that looks like it's heat from current flowing in the conductor inside those wires), and a nearby switch was misbehaving and is potentially showing some heat damage on a circuit board, and you say you're hoping someone would say it's a bad ground.
There isn't enough information yet to know what the original cause was, nor what all has been affected. We can't see and explore the vehicle as we're not there. You're the eyes on the scene, and witness to what occurred.

You can easily have multiple issues. And some of your observations of problems can be multi-causal. They may be rearing their heads at this time just because, or because they're related to what caused the huge current flow, or related to some damage done during that.   

That could be some reflow, it could be some rosin, or it could be a sealer sprayed on the board. The rug is in great focus, the board not so much so. 

So to be clear on some things,

With "all wire damage was on the harness nearest the stereo", does that mean to the car's harness or to the 'pigtails' attached to the stereo?

With "the rainy night my wife turned the defrost toggle on", you had the headlights on when this happened?
High beams or low beams? (no fog lamps seen, so that's out of the mix)
Without uninstalling it, can you see any signs of heat damage (melting, black) on the high/low switch on the left side of the steering column, around the 10 am location just in behind the dash?
Now pulling the light switch no longer turns on the headlights. Where the headlights on and then went out when that wire melting occurred following your wife turning the defroster switch on?
How much delay between turning the defrost switch on and getting the smell & smoke?

> By defrost switch, I assume you mean the switch to power the rear window defrost? If so, does the wires that go to the grid on the window look good? No shorts? No repairs to the grid that would reduce it's resistance so it drew more current than usual?

We've got issues with some gauges.
> the gas gauge and the coolant gauge needles max out on high when the car is started
> My temp and gas gauge are fine until I turn blower on or headlights, then the gushes go full up
Does that mean those gauges are good when you turn the ignition on, then max out when starting, then return to a normal appearance once running, until you turn on the blower or headlight switch?

One thing you can do, which may or may not help, but should be done anyways, is redo the battery's ground to the car's body. Ensure everything is off, remove the positive cable attachment from the battery, find where the negative battery terminal's cable goes to ground to the car's body (usually from the battery back towards the shock/spring tower, be it along the inner fender somewhere or on one of the nuts on that tower). Disconnect the cable ground and clean up any corrosion. Cover with dielectric grease and reattach. Connect the positive back to the battery. And while you're there, may as well clean both terminals and cable connections to the battery and cover with dielectric grease.

There's more, but we'll start with that.

[framedoctor]

With no key in the ignition and pulling the lights on the lights do not come on and the gauges go full up. With the key in the ignition and switch to accessory the gauges are normal until you pull on the headlights and still the headlights do not come on.
The ground from the battery is attached to the air conditioner bracket but I also see there is a grounding strap from the engine to the car frame.

[framedoctor]

The wires on the harness for the defroster switch visibly have no damage and the actual defroster grid on the back windshield doesn't show any gaps to be honest this car is almost like brand new. I understand that it is a 1988 and the wires themselves are 30 years old.
I also looked by the firewall by the brake pedal and I don't see any fuse box so I'm guessing that it's behind the dash?

[framedoctor]

Also noted is that the windshield wiper switch when activated does not affect the gauges like the blower switch and the headlight switch.

[Canoe]

The wires on the harness for the defroster switch visibly have no damage and the actual defroster grid on the back windshield doesn't show any gaps to be honest this car is almost like brand new. I understand that it is a 1988 and the wires themselves are 30 years old.
I also looked by the firewall by the brake pedal and I don't see any fuse box so I'm guessing that it's behind the dash?

Seems silly because you expected and can see that the rear defrost is fine, but if there was a short there somewhere it could account for a high current draw when that switch was thrown. Now with a further check of that circuit, we can probably eliminate that part of the defrost circuit.

Fuse box should be on the firewall, immediately to the right & adjacent to the emergency brake pedal assembly. This is also to the left of the brake pedal. On my two eagles, neither had this fuse box covered by any panel of any sort. (There is a panel that obscures the high/low beam switch that may have current/heat damage to it.) There were a number of changes in the '88 compared to the earlier Eagles, but I wouldn't expect the fuse box to be relocated.

[Canoe]

To narrow down what happened, we need a timeline, of what was what, when.

So with the gauges, lights, stereo, defrost, etc., what are you know you noticed that the function was good vs. bad, vs you think it was good vs. bad, vs. you don't recall, for:

• Eagle as you got it, with the original stereo in it
• Once the original stereo was out
• Once the new stereo was in
• that night but before the Defrost switch was turned on
• immediately following the switch was turned on,
• sometime later or the next day, before pulling the new stereo out,
• after pulling the new stereo out
• after pulling the defrost switch
• currently.

Yes that's a pain, but it could show what is possibly related to or is a cause of, or is independent of, or is a consequence of that high current flow, or a stereo going in or out.

If I've got the above order wrong, i.e., stereo or defrost switch in/out, please change it.

[framedoctor]

Inherited the Eagle. Ran great and stereo worked fine.
          1.) Never noticed if the gauges ever malfunctioned.
          2.) Never tried the defroster switch
          3.) Headlights and blower worked.
Removed old stereo
          1.) Noticed defroster switch buzzed in on position.
          2.) Never noticed a problem with gauges ( But they could have been malfunctioning)
          3.) I also do not know if blower and headlights worked properly at this point.
Installed new stereo
          1.) Defrost switch buzzing stopped
          2.) Blower and headlights worked.
          3.) Car ran fine and stereo worked both without car running and with the car running.
          4.) Drove several times a week during the day with stereo on and no problems noticed.
Rainy night
           1.) Kids wanted to cruise/listen to music and go for ice cream. it was about a 15 minute drive we got damp getting into the car.
After driving for about 5 minutes the car started to fog up so we turned on the heat and front defroster (fan). After about another 5 minutes we decided to turn on the back defroster. About two minutes after switching it on we could smell faint electrical smell and after about another minute noticed the smoke. Shut radio and fan off. Smoke stopped.
           2.) I drove the car home, it was just getting dark so I know I turned the lights on.
                    a.) I dont know if the lights were actually on
                    b.) Turned the fan on and my son said the smoke smell was getting stronger...shut fan off....drove home

Removed new stereo....fried wires on back pigtail...removed from harness
            1.) Defrost switch buzzed....removed from its harness
            2.) Noticed problem with gauges
            3.) noticed problem with headlights.

[Canoe]

Great!
Exactly what I was looking for.

Need some time to digest it. Hopefully something worth while can come out of that.

If you've time, do 'break', clean and reconnect those ground connections with dielectric grease. It eliminates those as potential grounding issues. If you do that, do check the fan & headlights again. Also check high vs low headlights, but please examine the high/low switch for melt/burn damage first; usually presents near the connector.

[framedoctor]

I cleaned battery posts.

tomorrow I will clean the grounds.
Is grounding to the AC bracket the best location?
Also the positive from the battery goes to a cluster near the Air pump that levels the car.

Ans the low/high headlight switch is on the column.

thank you

[Canoe]

Mine doesn't have the load leveling.

You usually want the connections between the alternator and the battery to be reasonable short, and of decent cable size for low resistance, so as much of the alternator's voltage possible/practical gets presented to the battery for charging it.

For the grounds, battery negative cable close enough to the alternator for the reason above, and to the starter due to the high current the starter draws when starting, again large cable; and to the body somewhere to ensure a good body ground.
So a nice thick ground cable going to the block near the starter takes care of the starter, and I believe you said there's something from the block to the body which would ensure the body is grounded, so that's borrowing the large cable from the battery neg to near the starter.

I wouldn't want to second guess the engineers who worked out the cable gauge requirements for the distance they're carrying a given current, without a problem that needs solving or someone has experience to improve something to avoid a problem or to get better/faster recharging or starting, etc.. That said, if you end up replacing a cable, it doesn't hurt to get a thicker cable for less resistance, particularly if you have a real cold season which uses more power with each start.

For example, a couple of the enhancements some Eagle owners choose to do provide shorter or better power. Using the GM ignition module so the coil can be provided full battery power all of the time (instead of through a ballast resistor when running) with the module limiting the current if necessary.
Installing relays for the low and high headlights, so the power driving the lamps doesn't loop back through the firewall to switches, and can have upgraded cable size with shorter runs from the relays to the lamps.

BUT, don't start changing things until you've got your problem fixed.
IF you find that a problem is with something that can be upgraded, consider if it's an upgrade you'd want, so you spend money once, instead of once for the fix, and a second time later for the upgrade. Of course that also depends on the $, now vs. later.

[Canoe]

p.s.
Do browse the Eaglepedia at http://amceaglesden.com/guide/index.php?title=Main_Page
for how to's
upgrades
etc.

[mudkicker715]

Great!
Exactly what I was looking for.

Need some time to digest it. Hopefully something worth while can come out of that.

If you've time, do 'break', clean and reconnect those ground connections with dielectric grease. It eliminates those as potential grounding issues. If you do that, do check the fan & headlights again. Also check high vs low headlights, but please examine the high/low switch for melt/burn damage first; usually presents near the connector.

dielectric grease is non conductive, just make sure to not put it on electric mating surfaces. its good to keep moisture out of connections, but not on contact points. something like Kopr-Shield is for electronic mating points. it keeps corrosion down while decreasing resistance.

[Canoe]

dielectric grease is non conductive, just make sure to not put it on electric mating surfaces. its good to keep moisture out of connections, but not on contact points. something like Kopr-Shield is for electronic mating points. it keeps corrosion down while decreasing resistance.

I'm not familiar with Kopr-Shield, but being non-conductive is exactly why I've been using dielectric grease on electrical contacts for over three decades. Blocks corrosion, particularly in the micro air gap between contact surfaces, and being non-conductive it can't creep and cause a short. I've never had a cleaned connection not work properly nor have any voltage nor current loss across the connection with dielectric grease applied.

[mudkicker715]

dielectric grease is an insulator. kopr-shield is a conductor. they have different purposes, so even though it sounds like dielectric is being misused it probably moves out of the way enough. now if that connection gets warm, it will tend to run, and possibly make matters worse.. if a conductive grease runs it will help knock out resistance on a bad ground. power wires are best left bare if near other power wires so they do not have runs to meet and conduct other near wires. that's pretty generic I know, just putting out a basic knowledge. you can research and see what you need to grow your own knowledge.

[framedoctor]

From FLUKE website:



Bad Grounds
High resistance among grounds can be among the most frustrating of electrical
problems. They can produce bizarre symptoms that don't seem to have anything to
do with the cause, once you finally find it. The symptoms include lights that glow
dimly, lights that come on when others should, gauges that change when the
headlights are turned on, or lights that don't come on at all.
With the new computer systems, high resistance in ground wires and sensor leads
can produce all sorts of unpredictable symptoms. Apply silicone dielectric lubricant,
available at radio supply stores, to connections before you assemble them. This will
reduce corrosion. Pay particular attention to ground terminals in the vicinity of the
battery, where acid speeds corrosion. Often a wire that is corroded through except
for a few strands will produce the same symptom as a corroded ground connection.
Just looking at the insulated connector does not insure that the connection inside is
good. Physically disconnect connectors and use a wire brush or sand paper to "shine"
the metal connections.