1972 radio issue question

[Stephen B.]

Putting my coupe back together and trying to perform a bench check of my radio. Note, this car did come from the factory radio delete, but the radio was added later (factory). The question is, according to to wiring diagram is the power plug with 3 wires, black, yellow, and gray. The yellow goes thru the tcs? Is that tcs system really needed? It was not connected when I picked the car up, which was not running of course. Thanks for any information about this.

[Mark E.]

Re: 1972 radio issue question

I've seen stranger things and I don't have the wiring diagram in front of me, but doubt the radio circuit ties into TCS.

I believe the radio uses a separate wiring harness, which was probably not added when the radio was installed in the field. I'd get one of those and the CSM which has the car's wiring diagrams, and install your radio properly.

[Stephen B.]

Re: 1972 radio issue question

Mark, the wiring diagram I have shows this which most likely wrong, but I did re check the drawing and it shows the yellow wire going to the TCS switch.....I just keep checking, Thanks for getting back to me

[Mark E.]

Re: 1972 radio issue question

Stephen,

Finally home so I can check the AIM and CSM. I have the 1970 edition of each, but I'm confident 1972 is similar.

AIM doesn't show detail for the radio power connection, but does show a wire harness for the speakers.

CSM's wiring diagram shows a single 3-wire connector to the radio:

- 20g yellow to the fuse panel for power. There's a dedicated fuse for the radio.
- 20g grey to a harness junction with 7 other grey leads for the lamp
- 14g black to a harness junction for ground

So the yellow power lead should tie into the RADIO fuse in the fuse box.

I thought there was a separate harness for the radio's power, but apparently this is part of the dash harness. This implies all cars, including radio delete cars, have this 3-wire connector for a radio. Maybe someone will confirm or correct this.

Could it be tucked away somewhere under your dash?

Does your radio delete car have a fuse location labeled RADIO in the fuse block? That's where the yellow lead begins.

You may be able to source the 3-wire radio connector with pigtails from Lectic Limited or a similar vendor.

[Larry M.]

Re: 1972 radio issue question

Steve,

I see what you mean about the TCS. Doc Rebuild's diagram shows it.

The attached files are from the 1972 CSM. Let me know if you'd like a close-up of any particular area.

Larry
new doc 2018-07-10 18.16.10_1.pdf

new doc 2018-07-10 18.18.14_1.pdf

[Ed D.]

Re: 1972 radio issue question

The TCS system is not necessary, unless you are having the car judged or going to local inspection. You can just by pass the solenoid and connect the vacuum hose from the carb directly to the vacuum advance. You will have to adjust the idle after the by pass.
Ed

[Stephen B.]

Re: 1972 radio issue question

Thank you all for the information about this. This will be a great help. I'll be glad to get the car back on the road after 16 years. I just wish the radio delete panel was not so much money.....it's just a blank off plate

[Joe L.]

Re: 1972 radio issue question

Thank you all for the information about this. This will be a great help. I'll be glad to get the car back on the road after 16 years. I just wish the radio delete panel was not so much money.....it's just a blank off plate

Stephen-------


Why would you want a block-off plate, anyway? Having a radio is much better than having a block-off plate. Block-off plates don't do much, at all, except fill the hole. With a radio, you can listen to music. Using an original radio and antenna and installed properly, no one will ever know it did not come with the car. Of course, once you make the hole for the antenna, there can be no "going back" in an undetectable way. However, since this car has apparently had the radio installed a long time ago, "that ship has already sailed". So, now getting it back to being an undetectable no radio car would be extremely difficult, if not impossible.

As far as the plates go, though, the GM originals do sell for Big $$$$. But, the reproductions are not that expensive at less than 200 bucks. So, if you really want to look at a block-off plate instead of listen to a radio, you could probably do it for less than what everything is going to cost you to re-install the radio with totally original configuration.

By the way, the reason that the original block-off plates are so expensive is that guys restoring an L-88, ZR-1, or ZR-2 are willing to pay Big $$$ to obtain a replacement for their worn out original plate. Those plates wear out so fast you would not believe it!

[Mark E.]

Re: 1972 radio issue question

Joe,

Any insight if the dash wiring harness is the same for radio and radio delete cars? The wiring diagram shows the leads and connector for the radio are part of the dash harness, so this suggests radio delete cars would have the radio leads/connector tucked under the dash somewhere unused.

[Joe L.]

Re: 1972 radio issue question

Joe,Any insight if the dash wiring harness is the same for radio and radio delete cars? The wiring diagram shows the leads and connector for the radio are part of the dash harness, so this suggests radio delete cars would have the radio leads/connector tucked under the dash somewhere unused.

Mark------I think they were the same but I can't confirm it since I'm in Italy and a long way from my references.

[Larry M.]

Re: 1972 radio issue question

UPC12, sheet B11, in the 1972 AIM shows the console wiring harness with a note to use 6" of tape to hold the radio lead to the harness assembly on cars with no radio. That is, there is no unique harness for non-radio cars.

[Mark E.]

Re: 1972 radio issue question

UPC12, sheet B11, in the 1972 AIM shows the console wiring harness with a note to use 6" of tape to hold the radio lead to the harness assembly on cars with no radio. That is, there is no unique harness for non-radio cars.

Cool. Maybe Stephen just needs to find his radio lead and plug it in.

I wonder if Chevy put in a fuse on radio delete cars? I suspect the cost accountants were on top of that.

[Stephen B.]

Re: 1972 radio issue question

Thanks for the reply. The radio is going back in. I did see an org. one on ebay for 1500 tho. Thanks to all

[Paul O.]

Re: 1972 radio issue question

Just for clarity the term radio delete is inaccurate. As a radio was an RPO such as U69 option or Extra Cost Option that needed to be checked when a Corvette was ordered. If it was not checked no radio would be installed.

[Mark E.]

Re: 1972 radio issue question

Just for clarity the term radio delete is inaccurate. As a radio was an RPO such as U69 option or Extra Cost Option that needed to be checked when a Corvette was ordered. If it was not checked no radio would be installed.

Good point Paul. Maybe the term "radio delete" came about because it seems as though these cars were built to have a radio (radio holes in the dash; antenna hole in the deck), then corrected (holes covered, filled) if no radio was ordered.