Installing Classic Auto Air in a '70 Charger

[1 Wild R/T]

Hook the feed from the alternator to pin 30
The power to the fuse box connects to pin 87
Pin 85 is grounded & pin 86 is fed from a keyed power source... It’ll draw about .2 amps so basically nothing...

https://www.summitracing.com/parts/pco-5591pt?rrec=true

 

[Kern Dog]

Still relatively new to this, so...
That relay in the Summit link, it has wires to solder onto ? I just lengthen them and attach them as you wrote above?
Is that something that I can get at an electronics store locally?
I do have some relays out back. A buddy tried to rewire my headlight harness using relays and screwed it up....I had to replace the harness with a new one so I have parts I didn't use.

 

[1 Wild R/T]

Your buddy needs a 2x4 upside his head... Cause done properly those relays make a huge difference.. And once you understand how to do it you should add relays to your headlights

However yes pretty much any standard 4 or 5 pin Bosch style relay will work

I actually buy them 50 at a time and have used over 500 in the last 15 years...

I have some with pigtails and some with the hard shell connector & bare crimp connectors

 

[Kern Dog]

Here are a few that I found in the shop:

No name brand:

 

[Kern Dog]

I have this Bosch relay:

I also have this Siemens relay...

In 2013, a guy in the local Mopar club offered to help me rewire the engine side of the car. One of his hobbies was automotive electrical. He had done some stuff with his 71 Road Runner and wanted to help. He rigged in relays and fuses and when I went to turn on the headlights, they did all sorts of wacky things. the '70 Charger has electric headlight doors that are wired through an underdash relay. I forgot about that relay and the new wiring really screwed things up. The doors wouldn't open or close at the right time, the high beams stayed on, it was odd. I didn't know what to do to fix it other than replace the modified wires with a replacement OEM style harness.

 

[1 Wild R/T]

I’ve owned a couple 70 Charger R/Ts, the headlights turn on and then the motor opens the doors, if wired properly relays should have zero effect on the motor/relay that opens/closes the headlight doors

I’d use the Siemens relay to power your fuse box, it’s high quality & rated 30/40 amps..
The relays for your headlights are about 50-50 between toss/keep and really the only reason I’d keep them is as spares cause no-name Chinese relays don’t have a great track record for reliability

 

[Kern Dog]

Thanks. I figure that the Siemens and Bosch are both quality parts. I also like the metal mounting tab on the Siemens relay.
I am considering the headlight relay kit that FBBO member "CRackedBack" sells. Plug and play with no modifications to the headlight wiring.
On DodgeCharger.com, there is a thread about how to use modern relays as a replacement for the factory headlight door relay.
I just sent off the brain box for my Dakota Digital gauges....They are going to reset my odometer. I won't have it back for at least 2 weeks so I have some time to fix a few other things.

 

[1 Wild R/T]

Rob builds nice harnesses, almost like he’s a professional or something..

 

[beanhead]

Hey Kern just for general knowledge...think of a relay as a simple lightswitch. Except instead of needing your hand to flip it one way or the other to operate, it's activated by electricity. Using the relay in your post #144 for an example, the terminals shown as 30 and 87 are the switch to the device you're controlling. The other terminals 85 and 86 are for the relay coil, which is what triggers the relay to close the switch(terminals 30 & 87) and complete the circuit. So if that relay was being used for a headlight, you would have 12v from the battery hooked to 30 and the wire out to the light on 87. The wire from your headlight switch would be on 85, and 86 would simply go to ground(or the other way around, polarity doesn't matter unless they're marked + and -).
Also noteworthy--that Seimens relay also has an 87A terminal, which is for normally-closed switch operation. That just gives you the option of using it to switch something 'off' when power is applied to the relay coil.
Different relays may use different numbers, but those symbols are standard; you've probably seen them in your years reading prints.
(What?! Carpenters reading electrical drawings?!)

 

[1 Wild R/T]

Hey Kern just for general knowledge...think of a relay as a simple lightswitch. Except instead of needing your hand to flip it one way or the other to operate, it's activated by electricity. Using the relay in your post #144 for an example, the terminals shown as 30 and 87 are the switch to the device you're controlling. The other terminals 85 and 86 are for the relay coil, which is what triggers the relay to close the switch(terminals 30 & 87) and complete the circuit. So if that relay was being used for a headlight, you would have 12v from the battery hooked to 30 and the wire out to the light on 87. The wire from your headlight switch would be on 85, and 86 would simply go to ground(or the other way around, polarity doesn't matter unless they're marked + and -).
Also noteworthy--that Seimens relay also has an 87A terminal, which is for normally-closed switch operation. That just gives you the option of using it to switch something 'off' when power is applied to the relay coil.
Different relays may use different numbers, but those symbols are standard; you've probably seen them in your years reading prints.
(What?! Carpenters reading electrical drawings?!)

Hey, Greg’s not your average carpenter, he’s given advice that got a members electronically shifted automatic transmission working... So he’s more than qualified to learn relays and schematics

 

[beanhead]

Hey, Greg’s not your average carpenter, he’s given advice that got a members electronically shifted automatic transmission working... So he’s more than qualified to learn relays and schematics

Oh I knows it!

 

[Kern Dog]

I lucked out....The nearby NAPA store had these:

I do wish though that they didn't have ALL white wires. I guess the shrink wrap will cover since every wire needs to be soldered on and lengthened anyway.

 

[Kern Dog]

Relay is in and wired as suggested. I was able to drill a hole to mount it flush with the bottom of the dash frame.

 

[Kern Dog]

The Dakota Digital brain box was in the mail on Tuesday...I was amazed that they got it back to me so fast! I was busy with some wiring on my Brother in law's Duster so I wasn't able to get back to the Charger until today.
The brain box is back in. All the wires are connected to it but I left the cluster out so I could see all the wiring. I had the Wife at the battery. I wanted her to connect the ground terminal while I looked at the wiring. Call me paranoid but I wanted to have her close so she could pull the terminal if I spotted anything heating up!
No heat, no smoke and no fire!
I did have three wires ran wrong. Two were supposed to be on ACC feed with one to constant power. The auxiliary fuse panel had power after the key was off. I reversed the connections and all was well. I taped up the wiring and secured the fuse box.

Oh, those crimp connectors are for the stereo...

 

[Kern Dog]

I am all back together...AND the unit is only blowing air through the defroster toward the windshield. The airflow stays on the defroster no matter how I move the selector. The fan switch works...the fan spins faster or slower. The heat can be adjusted by the lever but the air flow is stuck on defrost.
Yeah, it is Saturday and they are closed.
I suspect the control panel. If the other servos were to blame, I'd expect the air flow to stop as I moved to DASH or to FLOOR. The air keeps blowing but doesn't change from defrost.
I'll go over their troubleshooting section later or tomorrow. I just wanted to update.
A few good things came out of all of this.
The locking steering works again, so does the cigarette lighter. The extra accessories have a safer power source.

 

[1 Wild R/T]

I am all back together...AND the unit is only blowing air through the defroster toward the windshield. The airflow stays on the defroster no matter how I move the selector. The fan switch works...the fan spins faster or slower. The heat can be adjusted by the lever but the air flow is stuck on defrost.
Yeah, it is Saturday and they are closed.
I suspect the control panel. If the other servos were to blame, I'd expect the air flow to stop as I moved to DASH or to FLOOR. The air keeps blowing but doesn't change from defrost.
I'll go over their troubleshooting section later or tomorrow. I just wanted to update.
A few good things came out of all of this.
The locking steering works again, so does the cigarette lighter. The extra accessories have a safer power source.

The fix will likely be minor... Defrost is the default setting on modern cars for safety & I'm sure the aftermarket follows the same rule...

 

[Kern Dog]

Yeah, after all the other snags I have encountered, this couldn't be any worse. I bench tested it before I installed the unit. It was all functioning great then. It was nice to see the car buttoned up. All the little detours added a bunch of delays. I'm surprised that I started this in late August and I'm still not done. The guy that sold me the XH Charger loaned me a vacuum pump and gauges to finish it off. I'll have to go back several pages here to see what Randy wrote about the evacuation and charge procedure!

 

[CoronetDarter]

I'm with you on where the time flies during these projects. Unlike Ant on Wheeler Dealers who refurb's a vehicle in one week. [Tongue in cheek]

 

[HawkRod]

Hopefully it is something simple like a loose connector.

 

[bearman]

Kern dog, do you have a micron gauge to hook up on the evac gauges. The 30 inch is nice but running a micron gauge you can watch how low you can get it.warm up the can of freon before you install it that way you will get all the freon. Just a idea