1990 Service a/c light came on

[RivNut]

I pulled my 1990 Riviera out of its winter hibernation and am getting it ready for summer cruising.  I had changed oil, filters, etc before stowing it for the winter.  The battery needed a boost to get it started but once I had it running all was well.  Until after about 5 minutes on the road when the ‘service a/c light’ came on.  Does this mean a) that it’s low on refrigerant or b) something more. The service manual just says to have the air conditioner serviced.  It still blows cool, but not cold air.  Any advice on why the light may be on or do I find someone with some R12 and hope that’s all it needs?

 

Thanks,

Ed

[60FlatTop]

Here are the codes for the '90 Riviera A/C. You should be able to read it with a paper clip.

[dship]

3 hours ago, 60FlatTop said:

Here are the codes for the '90 Riviera A/C. You should be able to read it with a paper clip.

Also, your service manual gives you instructions on how to access codes via your HVAC unit on your dash.

[RivNut]

11 minutes ago, dship said:

Also, your service manual gives you instructions on how to access codes via your HVAC unit on your dash.

I have a service manual for a ‘93. Will it have the same info?  🤞

[dship]

I believe it will have the same instructions.

[Seafoam65]

Ed, your car is most likely low on refrigerant........when the code  sets the computer turns off the A/C

compressor. If your car is like the same year Cadillacs, you will need to disconnect the battery

for ten seconds after you get the A/C gauges hooked up and that should allow the compressor to come on

so you can charge it up. 

[RivNut]

Now to find someone with the correct gauges and some R12.  Thanks guys.

[DAVES89]

You are probably low on freon. However you should go the the "Reatta Owner Journal website as there is a "How to" tab on the top of the page. It will have how to read the codes, what the code means and how to interpret what is going on. Otherwise for what you are doing your '93 manual should work for the '90. Also you can probably get r12 freon on e bay as well as a gauge kit for r12. You will also need a special fill hose for the r12.