Help - What did I damage? - I reversed the jumper cables on battery charger

[69RRBeepBeep]

Hi.

I hooked up the battery charger leads backwards on 10 amp setting for 90 minutes.

1969 Plymouth Road Runner 383.

I returned to see a small wisp of smoke rising from the firewall 12” above the brake master cylinder.

(I’m not logging on for abuse. I’m feeling pretty stupid already. I just need some help on a 95 degree for a serious problem)

What did I ruin?

I turned the ignition key and see no power.

Can someone please offer me a list of things to check?

Thanks.

 

[dadsbee]

Probably cooked the fuseable link at the starter solenoid stud.

 

[440 PHIXX]

Check your fusible links.

 

[Paul_B]

Check your fusible links.

That’s my first thought.

 

[440 PHIXX]

Probably cooked the fuseable link at the starter solenoid stud.

Treed!

 

[69RRBeepBeep]

Thanks, especially for the photo.

 

[69RRBeepBeep]

Probably cooked the fuseable link at the starter solenoid stud.

thank you.

are these readily available at an OReillys or Autozone?

 

[dadsbee]

thank you.

are these readily available at an OReillys or Autozone?

No, but you can quickly verify it's the issue by jumping a wire from stud to the bulkhead.

 

[khryslerkid]

that's all it is.

 

[Paul_B]

Local parts stores might have something that will work depending on how correct you want to be. It might require some soldering and heat shrink tubing.

Here is an example by Dorman some local parts stores can get if not have in stock. Not sure if this is the ideal replacement but hopefully it will point you in the right direction.
Dorman Products - MCK35211

 

[dadsbee]

If it "popped", use an ohm meter on zero scale. Pull the ring terminal off the starter solenoid and check the fusesble link wire from ring to bulkhead to show it's "open". Then start clipping the wire off and checking each time it gets shorter. You may get lucky and it blew close enough to the ring that the wire is still long enough to put back on the solenoid.

 

[69RRBeepBeep]

1) Should I de-energize the system first by disconnecting the ground post on battery?

2) was the smoke from burning insulation on the fusible link wire? That should be visible.

This gives me a place to start, thanks.

When the temp abates this evening, I’ll grab a multimeter and check.

 

[440 PHIXX]

I got this one from Autozone. It’s for a Ford but was on the rack. Same 12 gauge and had the lug on one side. I spliced in to the replacement that a former mechanic had installed. As you can see it melted the bulkhead connector at one point. A big resistance problem on these old cars that Chrysler knew about as the police package had straight thru to the amp gauge with no bulkhead disconnect. It was more important to them to keep that assembly line moving. Probably burned more than a few old Mopars to their grave.
A good way to quickly check if the connection is OK is to turn on all your lights and blower motor. And use an infrared thermometer to check for higher temp. Any higher reading shows resistance, and therefore heat.

 

[MoparLeo]

Here is the obvious question. Did you check the battery yet ?
Never charge the battery in the car either. Charging creates hydrogen-sulfide gas. Can be explosive and is very corrosive.
I always remove the battery from the car, this protects the car's electrical system, engine bay components and the cars paint.
You need good ventilation for the gases. Top off the cells with distilled water only. Do a load test on the battery. It may be no good now.
Here is an article from the INTERSTATE battery company website.
A very comprehensive article on batteries, charging, testing etc.. Read completely through. Everyone can learn something.
The Essential Steps to Charge Your Car Battery

 

[dspur]

You are just getting an education on wiring and charging. We have all learned things by doing it wrong a few times.

 

[tonysrt]

The lady next door to me had a toyota and the battery went dead. She had a fellow down the block put it on the charger. A day or 2 later she asked me to install it in her car. I had no trouble putting it in the car, but the problem was when I tried to connect the cables it sparked mightily. Being a non domestic vehicle I had no idea why this problem occurred. I checked the alternator for possible bad diodes but no problem there. It seems the nice fellow reversed charged the battery. Since it was stone dead when he hooked it up there was no problem to tell him he was screwing up the polarity. A new battery solved the dilemma. So you never know what you can be walking into. Good luck solving your problem. That problem was more than 50 years ago

 

[Geoff 2]

Probably blew the alt diodes, which took out the fusible link.

 

[RJRENTON]

Probably blew the alt diodes, which took out the fusible link.

Not likely as the alternator diodes are forward biased; if the reverse polarity were applied, the PIV or
Peak Inverse Voltage rating of the individual diodes would prevent any current flow including the resistance of the stator windings will also limit current flow. The fusable link did it's job.....
BOB RENTON

 

[Geoff 2]

Fair enough, wasn't sure.

 

[Stumper]

Don’t feel bad I did the same thing last year and ruined a $350 reproduction battery. Some time after replacing the battery I found my mechanical regulator had burnt a wire too. I assume it was related..