Stalling, power steering out, melted battery cover. Help

[Colin86]

Car/relevant mods
Edelbrock supercharged FRS
Delicious tuning flex fuel and dbox
DW fuel pump/injectors
2017 stability control module swapped


Symptoms:
Right as I pulled into a parking lot from a casual drive the car died -all electronics cut out entirely as if the battery was disconnected and engine stalled. From there the car struggled to start, although when started would run normally until the electronics cut again seemingly randomly at which point it would stall. After the first stall the power steering was gone and the power steering light was on the dash. Didn't matter how many times I started the car after the electronics died and the car stalled, nor how long it was running between stalls -power steering remained dead (aka steering was quite heavy).

What I found:
Limped the car home just a few miles and found the positive battery terminal cover had melted. There are two sets of cables connected to the positive terminal harness, and the cables on the right began to melt the insultation around them. One of those was the wiring for the water pump for the s/c heat exchanger. I checked both the fuse and the relay for the edelbrock water pump and neither looked distressed. I checked the fuse boxes in the engine bay and also under the dash and no fuses looked dark or burnt (although I didn't pull any fuses).

Pictures in the folder below, let me know if you want others:

https://drive.google.com/drive/folde...2A3fa1LHzdQDwZ

I'm an electrical noob and don't know what to look for next. Help.

Thanks in advance!

[BirdTRD]

Is the melted wire the one that goes to the Edlebrock pump? Is this a new install or has it been installed and working for a while?

Wires will melt if the current being drawn thru them exceeds their capacity, fuses usually prevent this but they have to be in between the problem load (pump or short somewhere) and the source (battery). This excess load is killing your battery.

I wouldn't drive this until you figure it out, there's a real danger of an electrical fire from the looks of that melted wire.

[BirdTRD]

A poor electrical connection (at that crimp or the lug) will also generate that kind of heat and would not blow the fuse down line.

[Colin86]

Originally Posted by BirdTRD

Is the melted wire the one that goes to the Edlebrock pump? Is this a new install or has it been installed and working for a while?

Wires will melt if the current being drawn thru them exceeds their capacity, fuses usually prevent this but they have to be in between the problem load (pump or short somewhere) and the source (battery). This excess load is killing your battery.

I wouldn't drive this until you figure it out, there's a real danger of an electrical fire from the looks of that melted wire.

I installed the super charger nearly 6 years ago, flex fuel and supporting mods roughly 4-5 years ago. Car has been running great on both the street and track until this hiccup.

The wire that goes to the edelbrock pump is on that same nut, but I can't determine if it or the OEM wire underneath of it was the source of the heat as they both show fairly equal signs of heat fatigue. There is a fuse directly on the edelbrock wire slightly upstream (maybe 6-8 inches). I checked that fuse and it's good.

Would that nut slowly getting loose cause this type of heat? Unsure if it was loose, but I suppose it's possible.

After limping the car home I disconnected the negative battery terminal and haven't driven it since.

Not sure what to diagnose next. If anyone needs me to post more pics let me know what you want to see and I'll post them.

Thanks again for the help!

[Muskoka800]

Perhaps a long shot but I once had an intermittent power issue (88 Mustang GT).
Car cold started and worked fine but later would not hot start. Battery completely dead it seemed.
Eventually I discovered that a battery post had come loose inside the battery. I could ever so slightly wiggle it about. Replacing the damaged battery solved my issue.
Good Luck!

[Colin86]

Originally Posted by Muskoka800

Perhaps a long shot but I once had an intermittent power issue (88 Mustang GT).
Car cold started and worked fine but later would not hot start. Battery completely dead it seemed.
Eventually I discovered that a battery post had come loose inside the battery. I could ever so slightly wiggle it about. Replacing the damaged battery solved my issue.
Good Luck!

Thanks for the suggestion, this is an optimum battery that's only a few years old and the posts are firm. Battery is showing good health based on the smart charger.

Keep suggestions coming, I'm stumped.

[BirdTRD]

Check the fuse in the Edlebrock pump harness to make sure someone didn't stick the wrong fuse in there, should be 7.5A.

Are the wires melted anywhere else besides the end?
Check the crimp on both lugs going to that post (Edlebrock and OEM) make sure they are solid, a loose connection would generate the heat in that spot.
When current is opposed (resistance), the result is heat. Loose connection = high(er) resistance = heat.

If you have the tools, I would even go as far as to re-crimp a new lug on the Edlebrock harness to ensure it's good.

Visually inspect the wiring harness going from that terminal to the Edlebrock fuse and the OEM wire feeding the fuse box. If something rubbed thru prior to the fuses/fuse box and was intermittently grounding out, that could do it.
If you have a multi meter, with the battery disconnected, meter set to measure resistance, connect one lead to a good chassis ground and the other lead to the nut on the fuse block that connects to the + side battery post and start wiggling and poking the wire harness(s) (Edlebrock and OEM to fuse box) and see if the resistance jumps around. Should be 0 ohms and stay there, or very close to 0. If it jumps around, you have a short somewhere in that harness.

Electrical problems are challenging, even when you're hands on, nearly impossible over the internet. You might end up having to take it somewhere.

[radroach]

Could definitely be from a poor connection to the terminal, you get a voltage drop as load increases, requires more amps increase to make up for it, heat increases, and then your wires start to melt and the power steering fuse pops.

The way you have the wire connected, it might not be perfectly flush. Make sure you don't have any washers on the connector.

Though surprising that it would melt like that , if its only a 7.5A fuse, then might be something else like a short.

[Colin86]

Originally Posted by BirdTRD

Check the fuse in the Edlebrock pump harness to make sure someone didn't stick the wrong fuse in there, should be 7.5A.

Are the wires melted anywhere else besides the end?
Check the crimp on both lugs going to that post (Edlebrock and OEM) make sure they are solid, a loose connection would generate the heat in that spot.
When current is opposed (resistance), the result is heat. Loose connection = high(er) resistance = heat.

If you have the tools, I would even go as far as to re-crimp a new lug on the Edlebrock harness to ensure it's good.

Visually inspect the wiring harness going from that terminal to the Edlebrock fuse and the OEM wire feeding the fuse box. If something rubbed thru prior to the fuses/fuse box and was intermittently grounding out, that could do it.
If you have a multi meter, with the battery disconnected, meter set to measure resistance, connect one lead to a good chassis ground and the other lead to the nut on the fuse block that connects to the + side battery post and start wiggling and poking the wire harness(s) (Edlebrock and OEM to fuse box) and see if the resistance jumps around. Should be 0 ohms and stay there, or very close to 0. If it jumps around, you have a short somewhere in that harness.

Electrical problems are challenging, even when you're hands on, nearly impossible over the internet. You might end up having to take it somewhere.

Confirmed edelbrock fuse is a 7.5 amp. Crimps are solid, and they appear to have always been solid. Wiring other than at the ends looks to be in great shape. All grounds etc that I could find appear to be bolted in well. The only question is whether or not the nut that held the oem and edelbrock eye bolts was tight.... because it melted the surrounding plastic it was somewhat solid in there when I found it, but I can't tell if that was just melted plastic or if it was tight before the event.

The contact points for the OEM/edelbrock eye bolts are toasty and have plastic left over from where they melted the harness piece that connects to the positive terminal. I'll definitely need to replace the harness thing on the positive terminal -but I'm hoping to identify a root cause before swapping stuff and attempting to run the car again.

I don't have a multi-meter nor experience with them but I can get one and work on wiggling things to see what happens.

I'd happily take my car somewhere I could trust, but I'm not aware of anyone local.... Dealerships would no doubt balk at the amount of mods (nor do I trust them), and I'm not familiar with any mod friendly shops in the area. Anyone know any good shops in NE ohio? I've always been quite savvy and done all of my own work, going as far as building motors in other platforms etc.... but I'm not versed in troubleshooting electric gremlins.

FYI I added more photos to the folder specific to the question you asked.

Originally Posted by radroach

Could definitely be from a poor connection to the terminal, you get a voltage drop as load increases, requires more amps increase to make up for it, heat increases, and then your wires start to melt and the power steering fuse pops.

The way you have the wire connected, it might not be perfectly flush. Make sure you don't have any washers on the connector.

Though surprising that it would melt like that , if its only a 7.5A fuse, then might be something else like a short.

Perhaps this is as simple as the nut came slightly loose. Nothing else was loose and no washers present. If I can't find any smoking guns I suppose I'll swap the melted terminal harness thing and try to put it all back together and see what happens.

Unrelated but does anyone know where the power steering fuse is?

Thanks again for the suggestions, appreciate everyone's help

[BirdTRD]

Yeah, that all looks like it is localized to that post and nut. Maybe it was slightly loose, generating enough heat to start melting the block which made it even more loose and more heat.
Replace that block, the Edlebrock terminal, (OEM one may be OK but that's your call) Clean all of the contact surfaces and tighten everything back down. Start the car and monitor the temp of that connector with your finger or a temp gun if you have one, it should not get hot at all.

[soundman98]

looks to me like a loose connection. it didn't blow the fuse, which rules out a failed device. 7.5A is much lower than the wire should be rated for, so a loose ground issue would result in a blown fuse, not a melted wire.

the fuse is near the battery, and protected by the plastic loom-- the only thing that could result in a melted terminal is if the wire was physically pierced/damaged in the section between the battery and the fuse.

the fuse proximity also rules out the wire accidently powering something else that lost power--if something else shorted the wire, it would blow the fuse.


as i said first, all indications to me appear to be that the connection loosened over time. i don't see a reason to dig into the issue any further than the connection on the battery.


i would replace that oem fuse block that everything bolts to that started melting, scotchbrite/sandpaper the ring terminals until they don't show any of the signs of thermal discoloration, or pieces of plastic, and make sure everything is properly tightened down.

[humfrz]

Once you get your multimeter, I suggest you check the voltage at the battery with the engine running. It should be around 13 volts. If it is much higher, maybe your alternator has gone crazy and pumping too much current to the battery.



PS - The PS fuse is a 10 amp fuse in position # under the dash (at least on my 2013 FRS).

I hope you get it figured out.

(maybe it's just me, but I can't see your pictures - Google has a very old e-mail (g-mail) for me and no way can I remember the password - yes, I tried 1234, but it ain't THAT old)

[soundman98]

13-14.5v, depending on electrical load

[Colin86]

Thank you so much for everyone's help. Ordered a new positive terminal fuse block from Toyota and it's scheduled to arrive on Wednesday (although this dealership is notorious for delays on parts). Fingers crossed this is a simple fix!

Either way I'll keep this thread updated. Thank you again!