Installing Classic Auto Air in a '70 Charger

[Kern Dog]

Thanks for the kind words.
The underhood portion is almost done. If I were out there actually working each day, this would have been done a lot faster. Phone calls, favors for people, yard work, side jobs, buying that other Charger, lazy days...They all got in the way.
The belts are on. Fan and fan shroud are in. The new drier is in, all the lines are secured and the wiring to the compressor are in place and ready. The system needs to be evacuated via the vacuum test, then I can fill it. The instructions show to hand spin the compressor clutch 15-20 times after filling the system. It also clearly states to NOT fill the system with the engine running.
The interior still needs to be put back together. I removed the shifter and linkage so I could lay there and apply the sound deadener to the firewall. I had planned to leave the glovebox out in case there was some electrical glitch.
A local friend is supposed to help with the evacuation and possibly also the charge of refrigerant.

 

[Kern Dog]

SETBACK!

I got the car all back together today, console back in, I installed the right seat too. I got it running and let it run awhile. I had left the glove box out to wait to see if anything electrical would pose any trouble. Nothing sparked, everything worked!
I had a small leak at the fuel filter and fixed it. The belts are tight, no coolant leaks. All lights were working. I had about 15-20 minutes of run time in the shop. I put the glove box back in and let it run a little more.
THEN I drove it around the back yard. It was fine, then it started to stumble and stall. Smoke started coming up from the dash. I jumped out, opened the hood and yanked on the main power wire and split the fusible link to cut the power.
With the glove box out, I noticed that the pink wire I had running to the cigarette lighter was melted. It touched a few other nearby wires and they look like they have some melting where they were touching. I have some repairs to do before I can move forward on the A/C stuff. I did test the blower fan though. It worked great!
Picture below, right in the center you can see a burned spade. That is where I had the cigar wire connected.

T

That big red wire is for the new A/C system. It shows no damage, thank the Lord!

 

[Kern Dog]

I have the fuse box in my other Charger to use as a comparison.

The wire colored red with white stripe needs to be replaced. Somehow I'll need to spread the connector and replace the wire OR look through my stash. Maybe one of the multiple A-body harnesses I have has one of these that I can splice in. I hesitate to cut up the harness in this other car!

 

[Kern Dog]

I decided to start at the bulkhead. All wires looked great there, no signs of heat or blackening. The ignition switch wiring did melt though at the plug connections. I had to dig through the parts stash to find a spare plastic plug.

The red wire and black wire got hot. The red was the worst!

I soldered on a clean used end.

 

[Kern Dog]

The ignition switch plug :

Next up is the wires from the fuse block. I've added a few accessories to the car that have increased the electrical draw...Not a lot but they all need a power supply. The stock fuse box has 6 terminals. I had a panel from something with 7 terminals. I have no idea where the 7 pin fuse box came from but it looks identical to my stock one aside from having another terminal. I'll use the 7th fuse to attach the stuff I added to the car.
One of the main feeds to the fuse panel melted all the way back to behind the gauge panel. I lowered the column, removed the gauges and unwrapped the tape until dinner time.
I'll report more later.

 

[Kiwi383]

Very Interesting. Thanks for the updates.

 

[hunt2elk]

Yikes, that could have been a lot worse. Make sure you find the cause of the problem before firing it back up. I hate those stacking push on wire terminals, especially with higher amp loads. It doesn't look like the ac caused the problem, but even so, wouldn't it be a good idea to use a relay to power that?

 

[HawkRod]

Kern,

Sorry to hear about this - It seems highly coincidental that this happened after the A/C install. I'm sure all of our obvious first thoughts is that it was caused by the A/C system.

As I stated in my earlier post, this thing draws some serious current and will put a strain on your wiring. I initially wired mine to the A/C circuit and figured everything would be good, but I have now segregated the wiring for the A/C on its own circuit. What caused me to do this was two fuse failures and a third time when I felt how hot the fuse itself was.

Good luck and let us know what you find.

Hawk

 

[Kern Dog]

I am learning as I go on this and with a few of these discoveries, I am wondering ....Why am I just NOW learning this?

One of those things is...The power comes into the fuse box on one side and transfers over to the other side of the fuse. I had a few positive wires for added stuff connected to the main feed coming in. I should have had them attached to the other side so they would be protected by the fuse.
I also realized that it was my OWN ERROR that caused this.
I reattached the original cigar lighter wire after leaving it off for 4 years. I connected the positive to the lighter and attached a pink wire for a ground, then forgot to attach the other end of it. I moved to the engine side to do the rest of the A/C work. When I went to put the interior all back together I saw the pink wire and STUPIDLY thought it was the positive....and connected it to the fuse panel on the positive side.
Yeah, I am learning as I go on this.
The pink wire melted, a main positive feed melted and another wire heated up to where I don't trust it. I'm curious as to why it took several minutes to melt.
I am actually anxious in a good way though. I have the chance to improve this using some stock parts and some soldering. I'm getting better at it too. NOT good enough to charge others to do it but good enough for me.

 

[Dennis H]

Sorry to distract. The 3 speed blower in mine somehow is powered with the ignition off. I usually let the ac run all the time for no particular reason. With the blower on low, is this causing components to heat? I can just leave it off. Thought exercise was good.

 

[Kern Dog]

If anything aftermarket is powered with the ignition off, it could be powered by a wire that is attached to one of the constant power connections. This is also UNfused so it is at risk of burning or other damage.
The headlights, brake lights, horn and dome lights are all on a circuit that needs no key to work but the last three are FUSED, the headlights are not, they are ran through the main power feed from the bulkhead.
Looking at the back of the fuse panel, stuff started to become clear.

 

[Kern Dog]

4 years ago, I learned that the main power comes through the firewall bulkhead connector then it splits off to a few places.
*Power to the ignition switch.
*Power to headlights.
*Power to the fuse panel.

 

[Kern Dog]

I got lucky. I had only 2 burned wires. One of the main feed wires to the fuse box melted back to the welded splice/junction behind the gauges:

I replaced it with the same color and size wire.
I also replaced the fuse box. The stock one was a 6 fuse version, I had a 7 fuse version in the attic.
Notice the blackening on the 2nd and 3rd terminal at the top of the 6 fuse panel

Soldering into and under the dash....I had to use a paint stick as a backer. I pressed the soldering iron against the terminal and fixed 'er up.

Shrink wrapped afterwards....
Then the fusible link under the hood.

The fat red 10 ga wire is my main feed and passes through a drilled hole in the bulkhead. No spade connector there to get corroded.
Fusible link is a 14 ga.
The next step is to replace the ignition switch and wiring since the plug at the other end had melted. I could solder in each wire but I'd rather just do it right.

 

[1 Wild R/T]

My recommendation is find a OE/NOS or good used OE switch, the aftermarket switches are crap..

 

[Kern Dog]

Thanks. I have a few in the parts stash!

 

[1 Wild R/T]

Excellent

 

[CoronetDarter]

Nice work tracing down all the damage. The years have taken a toll on these 50+ yr old wiring harnesses.

 

[hunt2elk]

Nice job on the repair. At least you were able to figure out the cause of the problem quickly. You know how electrical gremlins can sometimes be very time consuming to diagnose.

 

[HawkRod]

Ditto on the nice job fixing this. If I has one dollar for every time I have screwed something up, I would be a rich man - but I guess that is how we learn!

The good news is this caused you to find and fix other things that were a potential time bomb that could have burned your car down, but you found them and fixed them. So a silver lining in all this...................

 

[Kern Dog]

Yeah, I can't blame the age or the wiring. This was my mistake.