1960s Question regarding 68 radio wiring

[chrisbutnut]

The previous owner of my car installed one of those new radios with the digital face.  I am going to remove that and replace it with an original radio.  I haven't really looked into what modifications were made to original wiring to install the modern radio, however I'm sure I'm going to have to do some wiring rework to put the original radio back in.

There's a radio wiring harness on eBay that says it's for a 67. eBay radio wiring harness

Will that work for a 68?  Photos of my radio are attached.  I can't figure out what the connector on the orange wire on the harness is for (can't find that connector on my radio).  Also, there's what looks like an RCA connection on the back of the original radio, and what looks like a coax cable on the right side, which I'm assuming is the antenna hookup.  When the modern radio was installed in my car, they connected a separate rocker switch to control the antenna, so i will have to rewire that as well.

(see photos below)

[chrisbutnut]

Photos

[TJ Hopland]

The harnesses for sale are usually the radio end that you would buy and wire to a universal radio that would then allow you to plug into the stock car harness.  These were not always available and even if they were when yours was done they didn't have to use one so who knows what you will find when you get in there.  Another reason those ones for sale don't always work or get used is many of the factory systems used a common ground for the speaker wires, most aftermarket systems require a dedicated pair plus when you get to a certain age you may have only had one speaker in many cars so there just wasn't much you could use in the original harness.

Looking at that radio it looks like the actual contact pins are what seems to be known as Packard 56. What is/was unique is the plastic body the snap into.  The Packard 56 shares the same actual blade size with the really common 0.25" (1/4") quick connect terminal so if the original connector is missing from the car you should be able to get quick connect terminals and crimp them onto the car wires and slide them on individually onto the terminals in the radio. 

You also need to investigate the speakers that are currently installed if you plan to re use them with the stock radio.  Many of the original speakers were higher ohms like 10 or higher.  Aftermarket is often 8 or 4.  The stock radio was designed to drive the 10 ohm so may not like trying to drive a 4 ohm.  You can go the other way, radio designed for 4 and drive a 10, you may just loose some volume and quality but having the amp higher and speaker lower can damage the amp.  The other factor is a factory radio maybe was only 5 watts so they had to make speakers that could be loud enough to work well with only 5 watts available.  Aftermarket systems are at least 25 and could have been 100's of watts so the speakers designed to work with those didn't need to be as efficient so they need more watts to achieve a decent volume level which the stock radio may not be able to deliver.    

[chrisbutnut]

The harnesses for sale are usually the radio end that you would buy and wire to a universal radio that would then allow you to plug into the stock car harness.  These were not always available and even if they were when yours was done they didn't have to use one so who knows what you will find when you get in there.  Another reason those ones for sale don't always work or get used is many of the factory systems used a common ground for the speaker wires, most aftermarket systems require a dedicated pair plus when you get to a certain age you may have only had one speaker in many cars so there just wasn't much you could use in the original harness.

Looking at that radio it looks like the actual contact pins are what seems to be known as Packard 56. What is/was unique is the plastic body the snap into.  The Packard 56 shares the same actual blade size with the really common 0.25" (1/4") quick connect terminal so if the original connector is missing from the car you should be able to get quick connect terminals and crimp them onto the car wires and slide them on individually onto the terminals in the radio.

You also need to investigate the speakers that are currently installed if you plan to re use them with the stock radio.  Many of the original speakers were higher ohms like 10 or higher.  Aftermarket is often 8 or 4.  The stock radio was designed to drive the 10 ohm so may not like trying to drive a 4 ohm.  You can go the other way, radio designed for 4 and drive a 10, you may just loose some volume and quality but having the amp higher and speaker lower can damage the amp.  The other factor is a factory radio maybe was only 5 watts so they had to make speakers that could be loud enough to work well with only 5 watts available.  Aftermarket systems are at least 25 and could have been 100's of watts so the speakers designed to work with those didn't need to be as efficient so they need more watts to achieve a decent volume level which the stock radio may not be able to deliver.   

Thanks TJ!  This is really helpful.

[Highwayman68]

The wiring for the radio is a part of the main dash wiring harness, perhaps they left some of it there. Look at page 15-3 in the Shop Manual, there is an all inclusive wiring diagram for the radio. Yours most likely was a non-stereo model so you will have to ignore the parts that apply to stereo models. Your car originally came with one front speaker in the center of the dash and one speaker in the right rear of the package tray in the back.

The connector pictured with the Black and Green wires is for the front speaker. The rear speaker is supplied by the Blue wire coming from the "Rear Speaker" spade in the 5 spade port. You can see a description of what each spade is for on the cover of the radio. Up and Down for the antenna is labeled as well as one for power for the radio and one for power for the antenna.

I probably have an extra connector with pigtails I can give you if you need one.

[The Tassie Devil(le)]

Don't forget that the rear speakers, if it has either one or two, there will be individual wire(s) going to the Speaker(s), and the Speaker(s) get their grounding vis the mounting screws.

Bruce.