Radio / Reverb wiring diagram

[Guest connl]

Finally have my rebuilt motor installed on my 65 Dynamic 88 convertable. Had it done by Thunderbolt in Houston. I'm very happy with the results. Now its on to other small projects starting with my radio / reverb system. Original radio was not working, so I bought model 7289313. The reverb unit is original (model 7284893). I need help on getting the two wired up and working. Car has rear speaker. Can anyone suggest where I get a wiring diagram that shows how the radio is connected to the speakers and how the reverb unit is connected to the radio / speakers? Also, the fader switch on the new radio I purchased is different than my old radio. Need help on where to find a fader switch for model 7289313. Thanks. Larry

[Oldsfan]

7289313 is a '65 full size radio, so the fader switch should be right unless it has been changed. What is the number on the radio that was removed? And what is the difference between the faders?

A shop manual will show the reverb wiring, but probably not in detail. At the risk of being simplistic, the front speaker lead is part of the wide plug that plugs into the back of the radio. This plug also includes power and radio ground. The front speaker is grounded to the instrument panel by the bracket. The blue wire coming out of the side (or the back by itself) is the rear lead and will run back along the sill into the trunk and will plug into the reverb unit. There should be a wire from the reverb unit to the rear speaker. The rear speaker is grounded similar to the front. I am assuming the reverb unit is grounded by attaching it to the car body, but it may have a separate ground wire. That should be it.

Paul

[Guest connl]

First, I appreciate the "simplistic" nature of your response. It's helpful. A few bits of info. Regarding what I believe to be my original radio, the id tag on the side is in pretty poor shape. The model number appears to contains 729841, but I could be reading something wrong. Can the full model number be determined from those digits? The serial number appears to be 31-96258. There are nunbers under the front right tuner control 7298971-1. The fader is a three prong switch for this unit. Each prong next to each other. The new radio seems like it needs a fader without the center prong. Regarding wiring, the reverb switch at the dash plugs into a three wire plug. The colors are red, green, and black. At the reverb unit int the trunk, these same color wires hook into the unit via a plug. I do not see any other wires coming into the unit or out from the unit. So, it appears as if the reverb is only connected to the dash switch but nowhere else? Have I confused you yet? So far I undersand from your intstructions how to wire the radio to the speakers. Now I have to figure out how to tie in the reverb and figure out what kind of fader switch is needed for the new radio. Thanks again.

[Oldsfan]

Probably that old radio is a 7298413 which is a '67 radio. Both faders should have the 3 prongs on the back, but the front should be different. Stock '65 controls should have 3 short spikes protruding from the ring.

Every radio I have seen from 1961 through 1972 (with the exception of stereo multiplex units) have those three prongs on the back of the fader. Radios without faders had a shunt wire in, I think, the lower two holes. I have never seen a fader without a center prong.

I got so simplistic with the reverb wiring that I forgot about the dash switch. I'll have to research that. Since the reverb delays the feed to the rear speaker, the feed for the rear speaker has to run into it somewhere, and come out to run to the speaker.

Here's something I just thought about - can you even have a fader and a reverb together? I've seen plenty of cars with reverbs, but I've never paid attention to whether or not they had fader controls.

Paul

[Guest connl]

Interesting point you make at the end. My new radio has a wire for the rear speaker coming out the side as you describe earlier. The seller told me it is a 1965 model. Could it be possible that it has a rear speaker feed, but no fader capability as you suggest? That would solve my fader switch issue. I just don't need one. Maybe the new radio I just purchased (possibly without fader capability) is more correct for use with a reverb than the old model I pulled out? I'm told the reverb in the car is original to the car. Still have to figure out where the speaker wire plugs in. Maybe I can pull it out to inspect further.

[Guest connl]

Found this on another web site. May provide more info regarding fader switches. Not really sure I understand what it means.

http://cgi.ebay.com/ebaymotors/NOS-1965-...tem250188417879

[Oldsfan]

OK, now I'm at home with my library. I shouldn't try to talk about such things without a book at my fingertips. I've got a schematic. Unfortunately I don't have the scanner hooked up at the moment, but it's pretty straightforward.

The red/green/black harness plugs onto the amplifier in the trunk and the connector for the switch on the dash. There are three more connectors attached to the switch. One is a solid green wire and the other is a white wire with a green tracer. Coming out of the radio on the passenger side should be a white wire with a green tracer (I mistakenly thought it was solid blue, but those are newer cars) that plugs into a connector attached to another white wire with a green tracer which runs to the rear speaker. That connection needs to be separated, the solid green wire from the reverb switch gets connected to the wire coming from the radio, and the white/green wire gets connected to the white/green wire running back to the speaker. The third wire coming off the reverb switch is brown and has a piggyback connector on the other end. Pull the green radio feed wire, running from the fuse block, out of the wide plug on the back of the radio and insert it into the short pigtail coming out of the piggyback, then plug the brown piggyback connector into the radio plug where you removed the green wire. The other wire in the radio plug is another white/green wire running to the front speaker.

Think of it working like this:

The fuse block sends power down the green wire, into the brown wire piggyback. From there it goes over to the reverb switch and into the radio. From the radio, the speaker output is sent out through the white/green wire to the front speaker. With the reverb switch turned off, it is also sent out through the second white/green wire, on the side, to the green wire that runs to the reverb switch, then through the green/white wire running from the switch to the rear speaker. Turning the switch on sends power from the brown piggyback feed wire to the red wire to power the amplifier. The rear speaker output is sent through the white/green wire, from the side of the radio, to the green wire to the switch, which then sends it to the black wire running to the amplifier, which does it's thing and sends it back to the switch via the green wire (which may or may not be the same color as the green wire which connects to the white/green wire coming out of the side of the radio - they call them green-A and green-. The switch then sends the output down the white/green wire to the rear speaker. Follow?

Now...

The owners manual says this about "Reverberator Equipped Bi-Phonic Speaker":

Provides concert hall reverberation giving full-dimension musical listening pleasure that can't be matched by any conventional rear seat speaker.

A switch located below the instrument panel activates the reverberator amplifier, and the rear seat speaker control adjusts the level of reverberated sound from the rear seat speaker.

So, not only was the rear fader available with the reverb, it was a required part of it. And, I learned something here, reverb is either on or off. I always thought you could adjust the delay. Like I said, I never had one of these.

According to that, you should need a standard three prong rear fader. There should be three matching holes next to the tuner shaft to accept them. Why do you say you think you need one without the middle prong?

Paul

[Guest connl]

Ok, so much for simplicity, but I understand your description. I just need to crawl under the dash and figure it out base on your description. The fader switch issue still confuses me. I can see the three holes in my old radio. These three holes do not exist in the new radio, but there is a side blue wire for a rear speaker. That's why I said I need one without the middle prong. I will need to take the new radio back out so I can inspect the right side knob and compare to my old unit. May take a few days for me to post what I find. Plese let me know if you ever get your scanner working so I can give you my e-mail for you to send the diagram. I could also take pics of my new radio right side dial to show you and send via e-mail. Not sure if e-mailing is acceptable behavior on this site. Thanks so much for your persistance in researching this issue. Larry

[Guest connl]

Found the wiring diagram in my chassis service manual on page 12-15. I was originally looking in my body service manual and could not find anything. No need to send. I guess at this point, I'm trying to figure out if the new radio I purchased will work with the reverb unit. Any thoughts on whether it will? Larry.

[Oldsfan]

Well, something doesn't add up with that new radio. The number you gave is for a '65 radio. As you can see in your schematic, the rear speaker wire should be white with a green tracer, not blue. My '62 rear speaker wire is white/green, and if I remember right, my '67 was also white/green. I had a '72 that had a blue rear speaker wire. That thing with the holes in it being missing is troubling, also. Like I said before, I've seen '61 through '72 radios have that piece. They even show it, and the shunt wire for non-rear-speaker-equipped cars, in the shop manual. The exceptions are stereos, where the fader is part of the separate multiplex unit and is controlled by a thin, notched collar surrounding the dial shaft. Sounds like maybe someone made some modifications to that radio.

Paul

[Guest imported_pete324rock]

I've read a little of this....I've fixed a reverb unit a couple of years ago-had a bad transistor that was old as the hills and not made anymore-talk about a challenge-it was an echomate with a built in fader.Long and the short,the fader is basically a potentiometer-three leads-two to the resistance and one is the sweeper that varies it from side to side-an ohm meter will verify that.The fader is necessary to get the effect in the car from the speaker in sync with the signal and the other speaker that is reverbed-too much of one or the other ruins the echo effect.I finally got mine working and said"oh is that what its supposed to sound like" and wondered if alll the energy to fix it was worth it.My advice,I would get the radio working with the two speakers first-then hook one of the speakers to the reverb-get that working-remember that the speakers usually in that era used a common ground between the two speakers-in other words three wires to run two speakers-of course ground(power) is the chassis and the heaviest wire would be positive power-preferably fused lead.All of this may or may not help.Following wire colors may seem logical as long as it holds true with common sense...pete

[Guest connl]

OK, got away for a few minutes on Thanksgiving. All of your input was very helpful. Problem is you are all dealing with a novice (me). After re-reading all these posts, I found out the new radio I installed had the shunt. That is why my old fader would not plug in. The shunt was in place, duh! Now the fader fits and works. The rear wire coming out of the radio is BLUE. Don't know why, but it is. I have found the wiring diagram in my chassis service manual. Now all I have to do is try to hook up the reverb. Hopefully it works. At least I know how to wire it. It only has three wires still attached. I will need to determin if I can solder the other three back on to the switch. Thank you all for your time. Sorry for the confusion I may have caused by my inexperience. But, that is the true benefit of this site. Guys like me can fix things based on input from experienced pros like you. Thank you so much and Happy Thanksgiving! Larry.

[rocketraider]

Heh heh. Wiring up an Olds reverb was fairly simple for me. The one that stumped me a few years back was a 1964 Pontiac reverb unit. Pontiac didn't incorporate a fader into the radio like Olds. They used a 3-position switch: front speaker only, rear speaker only without reverb, and both speakers with reverb. Took quite a bit of digging in the service manual to figure it out, plus a Delco Radio service manual. Didn't help that a previous owner had wired an automatic power antenna to this radio using the reverb amp power wire. Long story short, we got the reverb, factory power antenna, and Delco AM-FM radio functioning per design. Everything was there, just nothing was wired up right.

Now if we could just get that car's Electro-Cruise cruise control going, we'd consider ourselves geniuses!

[Guest jhatton5]

HELP!

I have a 66 Pontiac Grand Prix am radio with a reverb unit.

I have the wiring harness, but am unsure how to wire it up.

Can someone help me with a schematic?

[rocketraider]

I knew there was a reason that pile of paper had been laying on the kitchen counter for nearly a year!

On your radio:

There is a 3-cavity plug on the back or side. The yellow wire is the radio 12V power wire. The green wire goes to the reverb switch. There should be a brown wire coming off the side or back of the radio chassis, independent of the power/speaker wire plug. This is the reverb amp's power lead. AM-FM radio turns it on and off with the radio. AM only does not.

On the reverb switch:

There is a three wire ribbon that goes from the reverb control switch to the reverb amp in the trunk. It is the signal to and signal return from the amp.

A light blue wire runs from the reverb switch to the brown wire on the radio. It's the reverb amp's power wire.

The black/green stripe wire goes to the front (dashboard) speaker.

The black/white stripe wire goes to the rear speaker.

Both speakers self-ground to the car body thru their attaching screws. The radio chassis grounds thru its mounting bracket.

##

We used this for a 1964 GP that has an AM-FM, but I expect 66 is the same. Matter of fact most of the drawings were found in the 66 shop manual as the 64 book was downright skimpy on the Verbra-Phonic.

Looking closer, the AM radio may not have the brown power lead; 66 CSM shows the light blue wire from the reverb plugs into the 3-cavity plug with a jumper.