skpyle

No explanation needed...

Seth K. Pyle

SeanR

Coolants low

The Deputy

Let's straighten up those screw heads...keeping her ship-shape and all.

Less drag at cruising speeds also...in reverse anyway.

Glad you made it home safe and sound. Enjoyed reading your logbook pages.

Brian.

skpyle

SeanR: You're not supposed to notice that. 'Coolant' indicator is an electrical phantom I am chasing. Just like the disappearing AC.


The Deputy: Thanks! I very much appreciate it! Those screws came with the car. I am getting better ones shortly.
I will wrap up my road trip thread as soon as I get my act together.


Seth K. Pyle

zekgb

What are the symptoms of your AC issue?

skpyle

Hello zekgb! The AC worked last night. Today, nothing. The compressor clutch is not engaging.

I jumped the switch by the receiver/driver at the front passenger's side in front of the condenser. Then I realized that is the refrigerant pressure switch for the condenser fan.

I pulled the wires off the anti-freeze switch under the cowl cover. I heard the engine idle speed drop. I jumpered the wires and heard the idle pick up. I am going to say the anti-freeze switch is OK and has 12 volts going to it.

I saw the clutch coil wire connector in front of the passenger's side cam belt cover. It looks plugged in.

I did not have time to do proper troubleshooting. I was wrapping up changing the battery and the ground strap.
I work 3rd, so I need to be in bed soon.

I will try to do some troubleshooting tomorrow.


Thanks!

Seth K. Pyle

zekgb

If HVAC blower is working then a common failure point is the AC relay in the head unit. Dwayne has a great writeup on troubleshooting/fixing/upgrading the relay here. If the blower is not running at all then check the head unit power connector on the driver's side of the head unit (access by removing the carpeted panel on the side of the console) as it can become partially unseated leading to intermittent failure of the blower and AC clutch engagement.

bureau13

I assume jumping the pressure switch had no effect?

Does your AC button still light up when you press it?

jej3

Any ODO shot that ends in "928" is fantastic! I would immediately order some Deoxit and tackle the grounds and give the Central Fuse Panel a bath (disconnect ground strap, remove relays and fuses, apply liberally)

docmirror

HVAC AC pick relay is shot. Common failure, there's several repair methods if you search for 'AC relay' in 928. Use a bigger ice cube relay on the outside of the HVAC and run wires to it.

skpyle

zekgb: I was somewhat aware of the HVAC relay, and had read Dwayne's write up a year or so ago. Thanks for bringing it back up! I will start troubleshooting using it.



bureau13: I jumped the pressure switch and the condenser cooling fan started. Yes, the indicator light illuminates when I depress the AC pushbutton.



jej3: Yep, that is on the schedule. I already have a few cans of DeOxit handy.



DocMirror: You are probably right. I am laying in parts now to replace this relay.


Thanks for all the information!

Seth K. Pyle

dr bob

Seth--

Your symptoms say you are low on refrigerant, pointing away from the relay. Follow the diagnostic protocol in Dwayne's guide before you start throwing parts at it.

Chris Lockhart

Congrats Seth! Glad you got her home.

bureau13

That's what I was thinking as well. If the relay fails, does the AC light still come on? I have an HVAC controller failure, which I was sure was the relay, but it turned out to be a burned trace. The light was not coming on.

docmirror

I agree with this, but the relay is a >80% failure rate on these cars. Fix it now, and then diagnose. Falls under the heading of preventative MX.