Funny electrical issues.

[Hoojkue]

So I was on my way to work one day, a little over a month ago, and it was pouring outside. I had working windshield wipers at the time, but my A/C does not work so my car windows were getting foggy. Anyway, because of the fogginess of the windows, I didn't see the pothole coming up and I hit it pretty fast. After the bump my windshield wipers stopped working... but my A/C was blowing like crazy! After work I get home and as soon as I came to a stop they switched back again! So the good news is, I know that my A/C can work, the bad news is, I don't know how to get it going. I have the repair manual, but that wiring page is rediculously confusing! Thought I would share that with everyone here. And maybe get a little info at the same time.

[geezer]

The best advise I can give you is this. Disconnect the negative battery cable and spend the better part of a day inspecting, cleaning and reconnecting every connector and electrical connection you can gain access to. Also try to find the locations of all the grounds, which are notorious for causing problems. An Intermittent or Temporary Power Outage can be one of the most frustrating electrical problems to encounter. You can't fix it if it's working at the time. I have fixed many TPOs by this inspection/cleaning/ground tightening process and never did find what the problem was. That's OK though because if you are having problems with dirty/loose connections causing some things not to work, the wiring harnesses should be maintained before other symptons arise.

[Hoojkue]

Alright! thanks for the quick response, I was hoping someone would give me something to work on in this beautiful weather outside! I will let you know what I find.

[geezer]

Hey Hooj, do a search for a product that has been overwhelmingly recommended for cleaning electrical contacts, called Deoxit. I've been meaning to try it myself.

After you have finished inspecting/cleaning/reconnecting, you can reconnect the (-)battery cable and do a systems check. Make note of anything not working or any intermittant conditions. Then you can track down the individual causes in each instance. Any device only needs a power & ground to operate. It becomes only a matter of finding what's missing and where the interuption is. Good luck and make sure to check back here with your full report. I for one look forward to finding out what you find.

[Hoojkue]

Well, I was going to work on the electrical things but decided I needed to clean out my trunk and do some other projects...

http://classiczcars.com/forums/showthread.php?t=30381

Taking a foreign exchange student out tomorrow morning, then have the rest of the day off. Hopefully I will be able to start going through some wires! I will definately let you know if something works!

[Hoojkue]

OK, so I have gone through and cleaned and reconnected every wire I could get ahold of, nothing changed at all. it has been about 5 days, and today when I got out of my day job I turned my car on, and BAM A/C blowing away! Sadly it only lasted for about 15 seconds, and then it was off again. I can't figure it out. I am missing my A/C relay according to the diagram in the repair manual. I have no idea what it is.

[sblake01]

Like I said in the other thread, your ac wouldn't come on if the ac realay was missing. Check your low pressure cutout switch. It's located on the receiver/drier. That can be done by removing the two connectors from the switch and connecting them together. If your ac comes on and stays on either the switch is bad or there isn't enough pressure to keep the compressor running. A word of caution: Don't run it too long that way. If the pressure really is too low, bypassing the switch can cause compressor damage. When the switch is good it will turn off the compressor at anything below 28 psi low side pressure. Have you had the your ac pressure tested?

[Hoojkue]

well, I am moving in about 3 hours, checking right now to make sure I have everything packed, but I am off monday morning so it looks like I will try to do what you have stated above at that time. Also, no I have not had it tested, is this something I need to take it to a mechanic for, or can I do this myself?

[sblake01]

Well, I'm an HVAC/MVAC tech so I have gauges to check that. You'll probably have to go to an automotive AC shop. Do you know if your car has 'climate control' or regular AC?

[deftbird]

I have a pic of the blower motor relay from a 1983 280zx. I don't know if it is the same in your 1980. Mine was mounted with two screws on the passenger side right up front.

[sblake01]

A blower motor relay and an AC relay are two different things.