Aircon electronics

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vinnie55
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Aircon electronics

Post by vinnie55 »

Ok.

right, so I start my piazza up and try to switch on the aircon.
nothing happens. none of the little red lights are on on that section at all, it seems there is no power getting to it.
As far as I can tell, my guess is it has lost accessories power.
possibly a loose connection.
thing is.
I'm shit with electronics that I didn't wire myself.
(and even then i'm only good if it's audio)
I had a look under the dash and there were heaps of different wireing looms.

So I don't know where to start.

also. It's working now but the left elec window and the stereo were working intermittently, they both would not work at the same time, and vise verser. It is the stock radio and it did the thing it does when it's off. just shows the time.

this is why I believe it is an accessories power problem.

Any help will be most appreciated.


I am tempted to just take it to an auto electrician who knows what he's doing. stop me messing it up. - but i suspect their rates might be out of my budget.

cheers.
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Post by IZU069 »

Check the 3 fuselinks near the battery + terminal.
Probably one is a bad connection or has blown.

(I can provide more detail later if required. There are pics & schematics in some of my recent replies - eg, maybe to speedracer...)
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Post by vinnie55 »

GOT IT!

thanks heaps.
I sort of bandaided it.
I checked the fuses inside the car. And then i noticed the passenger side window and radio were on the same fuse (they also stopped working at the same time as eachother)

I went to unscrew the fuse box and the air con sprung back to life. It may still be intermittent, but at least I know the source now.

Then to fix the radio and left side window I jiggled the fuse for it, and it blew. replaced it and now it works all fine and dandy

thanks heaps.
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Post by IZU069 »

So another fault that would be fixed by my usual "first" advice - rotate all fuses; disconnect/reconnect all connectors.

Well done!
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Post by vinnie55 »

It's intimittently failing still, but i'm going to unscrew my fusebox and reconnect the wires on top of it propperly. most likely involving a soldering iron.
I'll let you know how it goes
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Post by vinnie55 »

Right. More testing has taken place.

The fault appears to be before the fusebox. which narrows it down a lot.
Still I have pulled it all appart before and still not been able to work it out.

however, we determened that the AC was not getting any power....or not enough. got some strange 7V readings from the multimeter.

SO.

We ran 12V to it from another part of the fuse box as a test and the AC fired up. herd a noise under the bonnet....? has me slightly concerned as to what it may have been. maybe a relay.

But my question now is. is the AC supposed to run on 12V or is it supposed to run on something lower, like 7.

I'm getting sick of trying to find where all the wires lead under the dash.
Very tempted to run a 12V 10A wire straight from the battery to the fusebox. maybe put a 10A fuse at the start of the wire run.

Thoughts?
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Post by IZU069 »

It is 12V.

It may be a faulty grey relay (or is it the brown one; grey I'm 80% sure).

The grey is a one-on when other off.
It is used for the starter & aircon so that the aircon is normally on, but when cranking, the aircon switches off.


Maybe that NC (Normally Closed - connected) aircon circuit has bad contacts etc.

BTW - you tried the usual thing - remove/replace connectors & relays; rotate all "same sized" fuses? That's to re-make bad connections and shift faulty/intermittent fuses to another circuit. A VERY effective technique and solves over 50% of problems on any old electricals...
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Post by vinnie55 »

Yeah I tried everything with the fusebox and surrounding wires.
However I didn't with the relay because I couldn't work out which relay it was. -tho now you say it's grey I might have a go at that.

If I run 12V from another source, I'll try to make sure AC is off whilst I crank.

Thanks for the advice, I'll run this past my mate and try again this week.
fortunately the weather has cooled off for now....
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Post by IZU069 »

I've got my dingy tiered to the rear door.... (No, not really, but....)
I turned the pilot light off my gas heater last week - that's why it's so farken freezing THIS week!


Have you got the wiring diagrams/schematics for the Piazza.
(IE - got the PiazzaManual CD? Well worth it. And ESSENTIAL for electrics. IMO you then (eventually) see how "easy" it is. [Emphasis on eventually. Assumption - that wiring diagram required more than one A4 page. Realisation - they have "broken down" into self-contained electrical wiring sections; hence repetition but sometimes with alternative "emphasis" - especially the repeated "power supply & flink" section.])


I'll try review your problem and check the diagrams BEFORE you next spend (too much?) time on it.
Alas my new job (which really SUCKs - that's a job description, not an opinion!) has absorbed all my energy and time.... (Except for our secret swim hole during my previous 2 Sundays off, but last Sunday went to mere "domestic" duties.)
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Post by wedgenut »

Righto, forget the grey relay, it is the starter relay and nowt to do with the air con. be very careful when messing with the AC. The Turbo Piazza has a low pressure cut safety device, if your gas pressure falls below a certain level (from leaks etc) it cuts out the power to the AC clutch circuit preventing it from operating. if you force it to operate with low gas pressure by wiring direct you will eject the compressor oil out into the lines and this starves the compressor, the balls will seize in the swash disc and there will be metal mayhem inside, the shards of broken steel will make their way right through the system pipes into your evaporator. It may be impossible clean it out so replacement may be the only answer which means full dash dismantling to get at it. Fixing the compressor will not be cheap either, probably cheaper to replace it.

So get the system checked by a pro, at least a pressure and leak test before playing with the wiring. You can check the under pressure switch easily enough, it is located on the drier bottle.
So many cars, so little cash
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Post by IZU069 »

Of course! As per the PiazzaManual!
(LOL!)

Thanks Wedgy. Brilliant!

Just another feature of the Piazza.
Another "pain", and yet a worthwhile pain when one understands the why and what...

So I guess it's easy to bypass.
(Hey man - gotta support the sparts and service industry!)
[Bypassing is a joke in case that was not understood.)
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Post by vinnie55 »

I think I PM'd Virtual R about the manual, havn't herd back.

I might run a new line from the battery, but with a relay running off the on switch.

Maybe I should take it to a pro.
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Post by IZU069 »

I was going to say check what Wedgy said...
(Maybe a temp bypass of the low-pressure switch.)


But now I realise Wedgy wrote:
wedgenut wrote:forget the grey relay, it is the starter relay and nowt to do with the air con.
Yes - it is a starter relay, but as I said, it disconnects the aircon whilst cranking.
Its BW is the starter circuit, its BG to the aircon relay.

The relevant Piazzamanual pages are 12-57 (p791, Power Source #1), 12-59 (p793, Starting) & pp 12-88 thru 12-91 (pp822-825, Cooling Fan & Air Con) - or p874 that combines 822-825.


And now I remember - Piazza, the car with 3 computers (4 if auto).
Unheard of for its time(?).
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Piazza airconditioning wiring diagrams

Post by IZU069 »

At last! Uploaded into GALLERY - not that clicking that link works for me (but select "Image Upload" to see what is there...).
NOTE that I probably won't post stuff like this again - the PiazzaManual.pdf has it all.


STOP PRESS - FINALLY!!
Image Upload does not accept "&" in filenames. Farken bluddy fracken poobum! Long filenames were fine, but I shortened "CoolingFan&Airconditioner" to just "Aircon" anyhow.


Below are the earlier mentioned relevant Piazzamanual pages 12-57 (p791, Power Source #1), 12-59 (p793, Starting) & pp 12-88 thru 12-91 (pp822-825, Cooling Fan & Air Con). (But not p874 that combines 822-825.)


Image

Image

Image

Image

Image

Image


The above are jpgs (quality = 50). The original much larger bmps have little quality improvement, but I could post q=100 jpgs. (I like keeping server space & transmission times down.)

They are modified screen-dumps from PiazzaManual.pdf
Sorry if they are wider than the normal window. (Normally I consider that unforgivable, but the uploading took long enough!)

I decided to retain the connector figs as they prove invaluable when actually finding and tracing the electrical components.
[ TIP: Ignore what the component is - find its connector instead; note its color if specified (and not color blind). ]


I used to HATE these multi-page diagrams - my Belletts, Wasps, Florians etc fit on ONE A4 page, or A3 if the "luxury" BIG prints LOL! - but now I love them.
They are well laid out with much practical information. That's once you crack their understanding. (Ask me if needed....)
EG - can you find the GRAY starter relay that Wedgy & I mentioned? (See Piazza-Electricals.12-59.p793PiazzaManual-Starting(mod)...)
Can you see it is either cranking else "air conditioning"?
And when de-energised, the air-con is enabled (ie, can be on)?


They should scale the same so that (same scale) printouts should line up. (EG - the 4 AirCon pages.)
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Post by vinnie55 »

I've seen the grey relay. and with the multimeter worked out which wire on it is ON position ignition power.

I tried to rewire it propperly with a relay I bought.
Used signal wire that I piggybacked from the grey relay (Ignition in the ON position) -which for some reason is 12mV????

Then the usual 12V from battery,
Earth
then the 12V line to the part of the fusebox.

Somehow this didn't work. likely 12mV is to little to set the relay off.... But that is the on switch power.... so.... right..... now what?

I fear I may have fucked something up when i first ran power to the circuit the dodgey brothers way.
because after all this it didn't work. -that and i herd a misc. noise under the bonnet which concerned me at the time.

After failing hardcore with this relay wiring I Tried dogey brothers way....
I got that thermo fan on the AC condenser to turn on, BUT The ac controll pannel didn't light on, fan didn't come on. no AC.
Also. wtf. but If you look at that part of the fuse box. there is a skinny blue wire, and a fat white one.
I ran power to each seperately. one of them turned the thermo on. the other.... turned the headlights on. WTF????
...or is it because I ran it from another unused part of the fusebox that had 12V at it???


Thanks heaps for the wiring diagrams.
I had a little look at them. little blurry but if they're in the workshop manual i should get that soon from Virtual R.
I'm gonna look at those again before i attempt something stupid.

It's getting to the point where I'm gonna have to see an auto electician/AC specialist.
At the very least I can give them these diagrams and some of the very helpfull advice you have all given.
Let them fix it propperly. It may cost a bit. but if they fix what I fucked up and do a good job i'll be happy.
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