Factory Accessory relay

So here we are in our unending search for electrical truth!

Car is a 1970 Dart. Car came with an accessory lighting package. In the car, that means that juice that would normally go to the cigar lighter (high class Mopar, no mere cigarettes here), instead plugs into an accessory wiring harness (see diagram if so inclined). which feeds: Map Light switch and then the map light (found on opposite ends of the dash), the glove box switch and light, the ignition switch lamp, the "ash receiver lamp", and then of course the cigar lighter. In the middle of all this is the Accessory Relay. plugged into the relay with a single three place connector are 4 wires: together there are a wire to the map light and a wire to the hot wire that originally went to the cigar lighter, in the second position is a wire to the ignition switch lamp, and in the third position is a wire going to the body harness and the key-in buzzer relay. In trying to remanufacture this accessory lighting harness so I can have a map light, I removed the AC vent from my unmolested 1970 Swinger , released the harness and pulled away the accessory harness. There I found this relay, unhooked and taped to the harness with electrical tape.

So the big question for me is: "what is the accessory relay supposed to do?" All the lights in my Swinger seem to work without the relay plugged in.

As I understand it the purpose is to turn off the ignition switch light in a certain short time frame (10 seconds or so). The only Mopar that I've driven that had that was my folks '69 Fury III. It turns that light on when you open the door and times the light off after the predetermined time.

Jim - I think you may have it! The ignition switch light in the Swinger never has worked that I know of (who would bother to take the steering wheel off to replace the damned bulb?). Since I've been driving 1970 Darts since 1972, I never even look where the key goes - I get in and muscle memory take the key where it belongs. I never even think about it. Thanks, now I can forget about the relay and not worry... it's a good thing because I don't know where you would ever find one to replace it if bad - it doesn't even have a part # on it, just MADE IN USA.

str12-340 said:

Jim - I think you may have it! The ignition switch light in the Swinger never has worked that I know of (who would bother to take the steering wheel off to replace the damned bulb?). Since I've been driving 1970 Darts since 1972, I never even look where the key goes - I get in and muscle memory take the key where it belongs. I never even think about it. Thanks, now I can forget about the relay and not worry... it's a good thing because I don't know where you would ever find one to replace it if bad - it doesn't even have a part # on it, just MADE IN USA.

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I actually replaced mine in my ‘73 Swinger. If you find the NOS piece they’re pretty pricey. I am extremely thrifty whenever I can be though and found out that they used the same part clean into the 90’s in various vehicles from Caravans, to Cherokees, and even Vipers. I bought mine from Auto Zone for $12. It was Duralast 19390 if you’re interested at all.

"Time delay relay" If you are interested in function instead of appearance, there are all kinds of modern time delay relays. If you find an astute electronics hobbyist, they might even build one.

Those same time delay relays are used in mopars into the 80s. Visit pick & pull.

Yep, I have a few spares as both my cars are wired with it. Any high end mopar or one with illuminated ignition key up to 1998 will have one plugged into the under dash fuse box. Thats where I got mine from.

It's called a time delay relay. As soon as you open the door the dome light power switches it on. That provides power to the contacts. These turn the ignition switch illumination light on. The contacts stay closed keeping the keyhole light lit, until it gets hot enough to kick the contacts open. That's when the light goes out.

Thanks for all the great information. If that's a replaceable item I'll bother to plug it in and give it a try. Since I have to rebuild the column anyway I'll make sure the bulb is good.