Aircon - what system do I have?

[KiwiPom]

Hi, the car I have bought was stated as having working aircon but I am 90% sure it is not working. I have taken some photos of the drier (next to power steering reservoir), compressor (has 2 filling points on top?), a pipe junction on the front left of the engine (water valve?). The pipework is all rubber hoses. From the drier a pipe goes through the bulkhead into the interior, I haven”t located a pipe returning from the interior yet though.

Are all these standard aircon components?

The dash console has a temperature control knob that does NOT have “aircon on” symbol at the far anti clockwise end BUT when turned fully anti clockwise the two electric fans DO come on, but no noticeable change occurs to the compressor clutch.

If I can establish I have a potentially working aircon I can start troubleshooting it….I have zero experience of aircon systems, albeit I understand the theory on how they work.

[Pete Boole]

I your car left hand drive? I've never seen the receiver drier in that position before. What year is your car? That is a picture of a Sanden compressor. Do you have photos of where the ac hoses go through the bulkhead to the evaporator? The last photo is of the water hose/casting that goes to the water pump from the radiator, but that's usually on the earlier 907 engines. Maybe the whole ac assembly is a retro-fitted set-up?

Pete

[KiwiPom]

I your car left hand drive? I've never seen the receiver drier in that position before. What year is your car? That is a picture of a Sanden compressor. Do you have photos of where the ac hoses go through the bulkhead to the evaporator? The last photo is of the water hose/casting that goes to the water pump from the radiator, but that's usually on the earlier 907 engines. Maybe the whole ac assembly is a retro-fitted set-up?

Pete

Hi Pete, its right hand drive, 1984 model year, is the sanden compressor original equipment on excels? Is it for an r12 system?

One of the pipes from the drier unit goes into the bulkhead just under the white water bottle next to the drier.

I suspect the ac is retrofitted due to the lack of a “aircon on” label on the cold/hot knob/switch BUT I guess the switch is the same for aircon and non aircon cars but not wired up on non aircon cars (that is very much a guess tho)

This looks very much like the compressor fitted “sanden sd507”
https://jbhauto.co.nz/products/ac-compr ... ck-hot-rod

[Pete Boole]

Sounds like it's definitely an add-on system. If you look on the chassis just behind the right hand engine mount you will see a bracket there - that's where the receiver/drier usually goes. The compressor is usually a 508, but it is probably bolted to the correct bracket on the engine.

It's of no consequence where all the bits go - so long as they are all there you'll be able to get it going again.

Yes - depending on when the system was fitted it may well be for R12. You need to change any rubber seals (there may not be any if it is all SAE 45° flares) and get all the old oil out of the system before changing to R134a. The expansion valve may well work OK with R134a.

R134a is less efficient than R12. If you need a new condenser fit the biggest you can.

If you need a new compressor stick to the 5 cylinder model - Bash (another forum member) - says he struggled to drive a 7 cylinder model with a single v-belt. Bash recently retrofitted ac to his V8 Excel - look for his detailed thread on the work he did.

Pete

[KiwiPom]

Sounds like it's definitely an add-on system. If you look on the chassis just behind the right hand engine mount you will see a bracket there - that's where the receiver/drier usually goes. The compressor is usually a 508, but it is probably bolted to the correct bracket on the engine.

It's of no consequence where all the bits go - so long as they are all there you'll be able to get it going again.

Yes - depending on when the system was fitted it may well be for R12. You need to change any rubber seals (there may not be any if it is all SAE 45° flares) and get all the old oil out of the system before changing to R134a. The expansion valve may well work OK with R134a.

R134a is less efficient than R12. If you need a new condenser fit the biggest you can.

If you need a new compressor stick to the 5 cylinder model - Bash (another forum member) - says he struggled to drive a 7 cylinder model with a single v-belt. Bash recently retrofitted ac to his V8 Excel - look for his detailed thread on the work he did.

Pete

Thanks Pete, its a learning curve for me but knowing the compressor I have is a major help, it looks like it is an r12, I will read Bash’s thread and try to do some basic diagnostics before getting it vacumn tested etc and (eventually) hopefully recharged with 134.

Can I check if there is any pressure in the system? It appears the charge ports have (dust?) caps on them, are the caps removable or would gas escape?

https://www.rparts.com/adnl-info/conver ... compressor.

[KiwiPom]

Well things have moved on a bit quicker than expected……
I found the (single) 12v supply wire to the compressor was not connected as the bullet had broken off, after a few checks and temporarily joining the compressor wire to the nearby 2 pin connector I established the clutch is working ok, taking about 3 amps, and the hot/cold knob inside the car turns the clutch on/off along with the 2 radiator fans.

As best I can tell the compressor is an Sanden SD507 (2.88” between “ears”)

I am reluctant to permanently connect the compressor supply back up, before doing further checks to establish there is oil/refrigerant in the system. There was no obvious cooling of air going on at tickover (central console vents). No obvious leaks. I have not yet located a low pressure switch. The drier observation glass did not change.

Any ideas on what else to check before I try to find an aircon mechanic? (I live in a small town so this may not be easy!)

e.g, Should I notice any pipes getting hot or cold with the aircon switched on and the engine on tickover? Can the pressure in the system be easily measured?

[KiwiPom]

After much thought I reattached the supply wire to the compressor and sent for a drive with the aircon switched on, and fan on full.

The smaller metal elbow (high pressure side) got too hot to touch, the larger (low pressure) metal also got hot but not quite as much as the low pressure side, the compressor body got hot. Pipes in/out of the drier were cool.

The air inside the car coming out of the central vent was fairly cool but not cold, in about 13 degrees ambient temp.

So not conclusive on whether or not the system is working properly?

[bash]

Try a simple home top up first, it might just need topping up.
https://www.ebay.co.uk/itm/273907864557 ... 6MQAvD_BwE

Or something similar.

Bash

[KiwiPom]

Try a simple home top up first, it might just need topping up.
https://www.ebay.co.uk/itm/273907864557 ... 6MQAvD_BwE

Or something similar.

Bash

Thanks Bash, I think you are right, the only issues are no ebay in NZ, and I don’t know if the system is filled with r134a or something else, like r12.

It was odd to find both the suction and discharge pipes to the compressor were hot, but pipes to the drier cool. On the one hand the discharge should be hot, but I guess (and that is a guess) the suction should be cool? Or does that also get hot by conduction from the compressor body?

The two small hex service ports, are those just “caps” I could safely remove without discharging gas? Then maybe measure the pressure (with engine stopped) using a tyre gauge? Or Is it worth buying a (chinese) double gauge setup to measure both service ports simultaneously?

I have found a local company that services car aircon, so once I have done every check I can do without buying specialist tools I will take the car to them to look at.

[bash]

I would let them top it up.

The machines draw out all the fluid left and replace it, the only problem you might have is that they may need the capacity of the system which is impossible with a custom setup like ours. I gave them the figures from the Excel manual and it proved to ok. I cannot remember what that was off the top of my head. If you have the big black Excel manual / bible the figures are in the aircon section.

Bash

[KiwiPom]

I’m still “researching” the aircon (after a couple of diversions into clutch and door lock issues) and it appears the system I have is similar to the 85 model year aircon, and has no low pressure valve (so I hope I have not ruined the compressor by connecting it back up, going for a test drive, and getting it hot, when it may not have been filled with oil).

It also has hoses and no metal pipes.