- Thread starter
- #861
Ok, I'll give it a shot.
Tearing down my HJ47 troopy (9 Viewers)
- Thread starter gswest
- Start date
This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.
can you attached small alligator clips to each blob prior, to ensure the circuit is open/closed after and before soldering?
- Thread starter
- #863
I did a soldering job on the circuit board. I did a wire and I put a little solder right over the area in question. We'll see if it helped. If not, I'll take the board to an electronics guy to trouble shoot. The pic shows a little lint from my rag I used to clean the board with; I didn't notice when I took the picture but I did clean it off before I put it back together.
bj40green
Tssss, tssss
The top left solder needs a retouch. The wire is on top instead IN the solder like the other two.
Good job!
Rudi
Good job!
Rudi
If this doesn't work check the relais between amp and AC pump clutch.
- Thread starter
- #866
It didn't solve the issue, so I'll check the relays and take the controller to someone who can check it out. Oh well.
- Thread starter
- #868
On a more positive note, I got the stereo in and it plays well. It has good volume which is good since the 2H can make some noise with the open exhaust. I'm driving it to work tomorrow for the first time in over 4 years; a big milestone!
That will be a great feeling, mate!
Nothing better than finally driving something that has taken the skin off knuckle's and bulk cash out of wallets!
My tip is you'll enjoy the drive (even if minor) immensely.
Nothing better than finally driving something that has taken the skin off knuckle's and bulk cash out of wallets!
My tip is you'll enjoy the drive (even if minor) immensely.
All a process of elimination mate so good luck with getting that aircon going. Good job soldering and like you said, a technician should be able to fault find for you. It may even be a burnt out resistor. If you have a multimeter, you may want to try out testing continuity yourself. Plenty of info available on how to do it, just takes time. That's all.
- Thread starter
- #871
Thanks!
- Thread starter
- #872
I wish I understood the connection between the heater blower and the A/C system. My heater blower didn't work as well and the resister on the heater blower looked suspicious so I ordered a aftermarket one which I dropped and broke in half. So, I ended up wiring it with no resistor. I couldn't get it to work unless I wired it with a switch that simply supplied a ground. It works with no key on which isn't a good thing. The original heater blower switch was replaced as well but still, no heater blower unless I rigged it with the other switch. Looking at the wiring diagram that BJ40Green posted; it does appear that the two systems share some wiring or circuitry?? I may go back to the beginning and sort out the heater blower issue and hope that it has an affect on my A/C issue. I have a feeling the A/C controller is not the problem. I did go back and add some solder to the repaired section of the circuit board so it looks like that circuit is good and it does show continuity on the meter. There are very few electronic repair shops around here so getting the controller checked out hasn't happened yet. I've gone online for tips on doing it myself and so far it's not looking too easy. I'll get the front diff switched in the meantime; worry about the A/C later.
Thinking more about Rudi's AC diagram, I believe the "oil switch" should really be labelled "refrigerant low pressure switch".
If my memory serves me correctly, Rudi and I have discussed in the past that this circuitry makes no sense at all with an oil pressure switch being there. (If it were to be an oil switch, it could only be your engine's oil switch because the AC compressor would NEVER have had one ... regardless of the fact that the wiring would still make no sense if it were to be a compressor oil switch.)
On the subject of having a connection with the heater-blower, you'll note that the diagram I inserted for a 1983 Commercial Vehicle shows a distinct linkup with the heater circuit.
However I don't really know why I posted that 1983 diagram because I have a 1981 HJ47 diagram in front of me right now. The different application-years doesn't make a lot of difference though because it still shows the AC control circuit coming off the "motor-run key position" and "20A heater fuse". (Note ... I'm not saying the heater needs to be turned on for the AC to work.. I'm just says that with OEM wiring the AC control circuit comes off the heater fuse.)
bj40green
Tssss, tssss
Or..... it's an added oil pressure switch re-routed into the wiring of the A/C unit so that the A/C only can work when the engine is running.
The oil pressure switch acts as a "main" switch.
My 0.02 cents.
Rudi
I guess that's a possibility Rudi. (Of course we know it can't be an oil switch like the existing EDIC-related one because that one opens on rising pressure.)
But I think it's doubtful it could be a "close-on-rise oil switch" too because there no harm done if the compressor clutch were to remain energised/engaged when someone's sitting in their HJ47 with their key in the motor-run position and their motor stalled or not-yet-started.
Even if an engine were to start with the compressor clutch engaged, that would impose negligible extra load on the starter-motor because the compressor starts working hard only when it's had sufficient time to reach its operating pressures (which takes at least a few minutes of running time).
Last edited:
It is a high/low pressure switch. There is no oil switch in a car AC system.
Normaly the AC system is recieving power from the blower switch. The power to the AC switch is on when the blower is activated.
Normaly the AC system is recieving power from the blower switch. The power to the AC switch is on when the blower is activated.
Last edited:
- Thread starter
- #877
Is the pressure switch we're talking about the inline switch that is on the refrigerant line? It has a 2 wire connection (both black).
Yes, don't know if it is high or low, the other one is likely mounted on/next to the dryer.
Hi Scott.
The "low pressure cut-out switch" is in the suction line which is
- the only line that gets cold during operation (and this line is often covered in insulation as we see in your photo although sometimes people also insulate the "liquid line" in the engine bay too)
- the line that's most often larger in diameter than any of the other refrigerant lines in the engine bay (and NEVER smaller ... unless an idiot installed your AC)
- one of two lines that connect directly to the compressor
I doubt you have a high pressure cut out switch .... so hopefully the above information enables you to confirm this switch in your picture is indeed your "low pressure cut-out switch". (And that would mean, in my view, that it is the switch that is mislabelled at "oil switch" in Rudi's diagram.)
Last edited:
You start with the AC switch, when it recieves 12/24v you continue with finding the relais that powers the clutch.
It should get a signal from the amp when the low pressure switch is closed and the thermistor is warmer than its minimum temp setting. The engine probably has to run for the clutch to work.
Correct me if I'm wrong here, it's been a while.
It should get a signal from the amp when the low pressure switch is closed and the thermistor is warmer than its minimum temp setting. The engine probably has to run for the clutch to work.
Correct me if I'm wrong here, it's been a while.
