Today the weather was very pleasant so I just had to do a bit of work on the van. I have still not refitted the dash board (one of the major interior jobs) This was left out because it covers the fuses and control relays where much work is to be done. Namely, the wiring alterations done by various "ustaads" had to be undone, the a/c system wiring checked out and ensured to be working as per design.
Today I attempted to find out why the a/c condenser/radiator fan was not working if the a/c was turned on - it was one of the main reasons for not fitting the dash board.
First step was to find the "correct" wiring diagram for the a/c control system for this van. After a bit of internet searching I found it:
This diagram has my notes on it in pencil. Here fuse S10 is switched power while terminal 30 and fuse S7 are always live.
Next job was to identify all the components in the van as per the diagram. I marked relays 30, 31, 24 and 32 on the diagram and proceeded to find them in the van:
Relays 30, 31 and 32 are identified. Relay 24 was already marked while relays 1 and 2 are additions by Mr. Ustaad
Using a multi meter I was able to identify that Relay 31 was bad and not signaling the condenser fan to come on. This one has been replaced and now the a/c system components are all working as per design. Of course I have yet to fill gas in the system. Gas fill will be covered in another post.
Next step will be to remove "Relay 1". This was fitted by Mr. Ustaad to make the radiator fan direct with ignition in an attempt to cure the overheating issue. "Relay 2" has been fitted to operate those hideous yellow fog lamps on the front bumper. If I am to make them operational, then this relay will have to stay.
The way the a/c in this van works is a bit wacky. The heater box and the a/c evaporator are two separate items with their own fans motors unlike today's cars where the heater coil and the evaporator coils are placed in front of each other and a singular fan blows air through both of them. One can turn on just the a/c blower fan with out turning on the a/c compressor just like normal but that also turns on the a/c condenser/radiator fan - rather crazy but that is the way it is designed. If the wiring diagram is followed, relay 31 is energized via terminal 'C' of the evaporator fan switch. If it was my design, I would have energized relay 31 via the thermostat switch. Meaning that every time the compressor clutch was energized, the a/c condenser/radiator fan would be turned on. Anyway, this set up has the advantage of providing constant cooling to the condenser/radiator regardless of compressor being on of off.
I guess the next step after electrical cleanup would be to fix back the dashboard.