Identify my installed air con (1998 300TDI 110)

Inspired by this thread, I went back to my AC fan speed issue.

I wondered if running the fan at 16V might be better for moving more air, and whether that would lead to premature failure.

I spoke to an auto elec friend, who told me how to measure voltage drop.
Put the multimeter in Volts setting, then place one end on the +ve wire of the (in this case) fan and the other end on the +ve battery terminal. It should read 0 if there's no voltage drop. You can do the same with the negative wire and the negative terminal to measure drop on the negative side. Voltage drop may be caused by long wiring or poor connections.

My fan was running at 8volts with the battery at 12.6V !!!!!

There was a 1V drop across the plug for the fan alone. The -ve side had no drop.

I did some by-pass surgery and ran 6mm wire from the fan side of the plug to a 12V outlet I have beside my cubbybox. Now the fan blows with gusto. I'll fit a switch to it, and it can be my AC Boost switch. I turned the thermostat dial to the right a bit more, and air temp dropped from 4.C to 0.C.

I wish I'd done this 10 years ago.

That's great news.

I own a 93 defender 110 , 200Tdi with AC. When I turn it on ,the compressor goes on and off continually. I was told it was the 2 function switch!! But I was thinking it might be a relay? Has anyone had this problem?

Quote:

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Originally Posted by Michael2

Inspired by this thread, I went back to my AC fan speed issue.

I wondered if running the fan at 16V might be better for moving more air, and whether that would lead to premature failure.

I spoke to an auto elec friend, who told me how to measure voltage drop.
Put the multimeter in Volts setting, then place one end on the +ve wire of the (in this case) fan and the other end on the +ve battery terminal. It should read 0 if there's no voltage drop. You can do the same with the negative wire and the negative terminal to measure drop on the negative side. Voltage drop may be caused by long wiring or poor connections.

My fan was running at 8volts with the battery at 12.6V !!!!!

There was a 1V drop across the plug for the fan alone. The -ve side had no drop.

I did some by-pass surgery and ran 6mm wire from the fan side of the plug to a 12V outlet I have beside my cubbybox. Now the fan blows with gusto. I'll fit a switch to it, and it can be my AC Boost switch. I turned the thermostat dial to the right a bit more, and air temp dropped from 4.C to 0.C.

I wish I'd done this 10 years ago.

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An auto electrician who got my '97 system going properly some years back told me not to run it below 6˚ at the vent as it will freeze the condenser up and stop the whole thing from working. to that end I got a cheap little 12V digital thermometer and fitted it near the vent closest to the controls. When my thermostat knob is a t the 3 o'clock mark, it's about 6˚

Don.

Just purchased a lovely specimen from your continent a couple months ago. 1995 110 300tdi that is rust free! Loving it here in the US! I have the same air con here. Previous owner said it was not working, but I’m not even to the point of troubleshooting yet because I’m trying to figure out how to turn it on! Here is my switch:

Attachment 166286
I’m missing the “top” dial it seems. My lower dial spins from 12 o’clock, counterclockwise, to 3 o’clock. Is that correct? I also cannot turn the protruding shaft with my fingers, but before I put a bit more force to it, I wanted to check how that shaft/knob should operate?

Thank you!

G'day TripleE,

An aussie 300tdi in the US is surely somewhat of a rare beast!

The lower dial is your temp control and should spin from about 12 - 8 (off the top of my head). The top dial is your switch for the fan settings (3 different levels). A gentle clockwise turn with pliers should be safe.

Need to get mine regassed actually. Don't expect wonders from it though, just makes the engine feel even more asthmatic.

Cheers, Mules

Correction,

Bottom dial should spin clockwise from about 9'o clock to 7 o'clock,

Top dial from about 9 - 12 (if you have one of course)

Quote:

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Originally Posted by TripleE

Just purchased a lovely specimen from your continent a couple months ago. 1995 110 300tdi that is rust free! Loving it here in the US! I have the same air con here. Previous owner said it was not working, but I’m not even to the point of troubleshooting yet because I’m trying to figure out how to turn it on! Here is my switch:

Attachment 166286
I’m missing the “top” dial it seems. My lower dial spins from 12 o’clock, counterclockwise, to 3 o’clock. Is that correct? I also cannot turn the protruding shaft with my fingers, but before I put a bit more force to it, I wanted to check how that shaft/knob should operate?

Thank you!

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If you measure the diameter of the shank and whatever landing is on it, then search radio parts stores or Ebay, you might find one that fits. I don't think there are any spare parts for those switches available here.
With a trim, something like this might do the job. you should be able to find something over there.
Don.

Edit: This one might be better

Quote:

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Originally Posted by Mules

G'day TripleE,

An aussie 300tdi in the US is surely somewhat of a rare beast!

The lower dial is your temp control and should spin from about 12 - 8 (off the top of my head). The top dial is your switch for the fan settings (3 different levels). A gentle clockwise turn with pliers should be safe.

Need to get mine regassed actually. Don't expect wonders from it though, just makes the engine feel even more asthmatic.

Cheers, Mules

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Quote:

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Originally Posted by Mules

Correction,

Bottom dial should spin clockwise from about 9'o clock to 7 o'clock,

Top dial from about 9 - 12 (if you have one of course)

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Perfect information, mate! 😉 That’s what I was looking for! I can turn it with my fingers and feel the 4 (0,1,2,3) positions. Fan blows! I’m definitely not expecting wonders, but I’m sure glad it’s there; hope it can knock the edge off the heat when the time comes. Probably get it gassed up next. Thank you!

My bottoms dial does spin approximately 3/4 of the circle (actually just a touch farther like you describe from 9 to 7). Even though mine is in a different position, it sounds like it travels the distance you describe. Perhaps the dial just needs to be indexed correctly to match yours. 9 is the warmest setting and turning clockwise to 7 is coldest?

Quote:

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Originally Posted by Don 130

If you measure the diameter of the shank and whatever landing is on it, then search radio parts stores or Ebay, you might find one that fits. I don't think there are any spare parts for those switches available here.
With a trim, something like this might do the job. you should be able to find something over there.
Don.

Edit: This one might be better

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Very good suggestion, I’ll certainly start the search! If by chance you ever do come across one, please let me know! Thank you!

Just looked at my switch, normally just use it without paying much attention....

Low Km, its led a sheltered life over the past few years but I did notice that the top knob has been damaged at some point.

Thanks to the comments by Michael2 I might investigate the fan wiring at some point in the future.


Colin