FlyingV5150

Hi all, I'm a newbie to these forums as well as to the cutlass I bought about a month ago. I love it and it runs well, but seems like it has a host of electrical problems.


First, the electric rear defroster doesn't work. The light on the dash comes on but the defroster doesn't seem to do anything. I haven't metered the wires going into the window yet but what should I be looking for?


Also the radio doesn't seem to work. It lights up when I turn the **** on, but can't get anything to come in. I believe it is the original AM only radio but I'm not completely sure of the functions of it, any pointers?


There are other problems, but those are two big ones I would like to get fixed. Any help anyone could provide would be great. It is a 72 Cutlass Supreme, 5.7L 350. If there is any other specific information I should provide, let me know.

matt69olds

Do you have a factory service manual? If not, that is money well spent. Don't buy a cheap Haynes manual, find a factory manual, its well worth it. If I remember there is a circuit breaker that powers the defroster grid, a timer that plugs into the fuse box, and it is wired into the charging system ( assume to keep it from operating unless the engine is running).

Start your diagnostics by inspecting the connections at the glass. One side will have power, other side is ground. If you lightly touch a test light to the defroster grid wire, the test light should light up. As you slowly move the test light to wards the ground side of the window, the test light should get dimmer. Check every wire, the result should be the same and even.

That is a pretty rare option. I have seen it in the service manual, but never in person. The blower style defroster is pretty common. Good luck!

matt69olds

As for the radio, check the fuse. If its good, check for power at the radio on the yellow wire. If the fuse is good and power is present on the yellow radio wire, the radio needs to be repaired.

joe_padavano

Is the defroster the blower style in the package shelf or the grid style on the glass?

Assuming you have power to the radio, the power amp transistor in these radios is notorious for failing. The transistor can be replaced pretty easily if you can solder.

FlyingV5150

The defroster is the grid type, i dont have a factory service manual, only the old owners manual, where could i get a service manual?

starfire

Do you get static out of the radio and no stations come in, or is it completely silent when you turn it on?

Go here: http://wildaboutcarsonline.com

Sign up for free and they have Chassis Service Manual and Assembly Manual (for free as well).

Now me, I like the paper ones too, so if you go to ebay and search: "1972 oldsmobile chassis service manual" you will find a variety of them for sale, different prices for different conditions (and sellers, some are crazy).

Do this search "1972 oldsmobile assembly manual" for the assembly manual.

For both the manuals you can also get them on a CD rom. I have both paper and CD and I use Wild About Cars, just because I got the other one's before WAC had them on their website. Even at that, I would still have a paper copy. I actually keep two paper copies, one for the garage and one for the house. But then again, as most on this board can tell you, I'm crazy.

One last thing, WAC does not have a Fisher Body Manual for your car, so you will want to get a paper or CD copy (the CD's usually have both Chassis and Body manual and sometimes Assembly). In a pinch, most of the information in the 1970 FBM will apply to your car.

Here's a taste of what WAC will do for you: (the diagram shown is for heat only, the next page of the book has the diagram for a car with A/C)

1972RWDefogInfo_zps70ee4bc3.jpg

oldcutlass

The radio issue could be as simple as the speaker being bad.

FlyingV5150

Radio is completely silent when i turn it on. Seems like the manuals you mentioned starfire would be INFINITELY helpful. Think i will definitely head over and do that.

Also something odd that might be connected with the defroster, the High setting on the fan wont work, i think someone mentioned this shuts off when the defroster is on to prevent too much power draw or something, but its off all the time. Possibly connected somehow?

starfire

Are you sure the speaker is hooked up? Are you sure there is even a speaker? (asking these questions from experience).

Octania

Also, if the antenna or its connections are bad, the radio won't play any noise even if the radio itself works.