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Discussion Starter #1
1.) Is the little triangle directly to the left of the gas gauge meant to light up when the fuel level hits empty or near empty? The light works when I start the car, but I've never got it to come on because of low fuel. Maybe there is an adjustment to make it come on at the line between 1/4 and 0?

2.) I just replaced the aux condenser/radiator cooling fan controller, as part of an A/C system overhaul (new drier also). The fans cycle on/off as they should, but they seem to cycle too often. At idle with the car stopped, they will turn on, run for a few minutes, then turn off for 1 second, then turn back on. Sounds like a short cycle. Outside air temp is around 75. The fans never did this before. They would cycle on/off in longer intervals. I'm not sure if this is how they were meant to run or something is wrong? The car maintains a constant operating temp and the A/C cools very well.

Thanks!
 

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1 Yes it's supposed to light up. Don't know if it's adjustable.
2 Is the tempsensor in the drier installed in the correct way?
It's supposed to let the fans run if your R12 reaches 57 degrees centigrade or thereabouts. Do you have the correct amount of R in the system?

gr J
 

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The fuel reserve warning lamp will illuminate when the key is turned to steering lock position 2 and will go out after the engine is running

If the warning lamp stays on after the engine starts or comes on while driving, it indicates the fuel level is down to the reserve 12.5 l (3.3 US gal)





see P. 65 of your owner's manual
 

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Discussion Starter #4
1 Yes it's supposed to light up. Don't know if it's adjustable.
2 Is the tempsensor in the drier installed in the correct way?
It's supposed to let the fans run if your R12 reaches 57 degrees centigrade or thereabouts. Do you have the correct amount of R in the system?

gr J
Could a low R12 charge be the problem? I had a licensed pro actually put the stuff in. He used 3 of my 12 oz cans, which I thought was strange. I thought there was a 46-48 oz charge and he put in 36+/-. When I look in the bubble window on the drier, I see lots of bubbles with the system running. Is that good or bad? I used to know, but its been a long time since I've done A/C work. It does seem to cool very well, so I'm a little puzzled.
 

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Could a low R12 charge be the problem? I had a licensed pro actually put the stuff in. He used 3 of my 12 oz cans, which I thought was strange. I thought there was a 46-48 oz charge and he put in 36+/-. When I look in the bubble window on the drier, I see lots of bubbles with the system running. Is that good or bad? I used to know, but its been a long time since I've done A/C work. It does seem to cool very well, so I'm a little puzzled.
IIRC, you're supposed to get bubbles when the compressor kicks on, then it should 'clear'. The clearing is not air, but the refrigerant filling up the viewing port.

It sounds a bit low. Not much, maybe 8oz.

The fuel light I've found, on mine, comes on at about 16L/4 gallons left. It's spot on, every time, and it's accurate enough so that, if I drive 30 miles with it on, I'll throw a gallon in, until I find decently-priced fuel.

In prior vehicles, I've found the low-fuel sensor is somewhat adjustable, once you pull the fuel level apparatus. Way more work than it's work, on these machines.

I'd say you likely haven't run it low enough, which can be difficult to believe, at times, but I can get 500 miles from a tank, under the right conditions.
 

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Bubbles isn't good. He should have charged it per the MB specified amount.
 

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Discussion Starter #7
I guess I just haven't ran the gas as low as need be to set off the light. I'm always afraid when it gets anywhere near empty, because the needle becomes volatile... every time I go around a corner the needle goes up, then way down, but the light never comes on! The needle is dead on whenever the tank is more then 20% full.

I guess the R12 must be low. I'll have to go back and complain. Do you think that is what is causing the fans to be so random and short cycle? Does the compressor shut down with too low of a charge or is this system not that advanced?
 

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I guess the R12 must be low. I'll have to go back and complain. Do you think that is what is causing the fans to be so random and short cycle? Does the compressor shut down with too low of a charge or is this system not that advanced?
Yep, if the charge is low, the system will short-cycle the compressor, and the fans will follow, as they're in synch with the compressor. There is a pressure sensor in A/C systems dating back to the stone age which will allow a compressor to kick on, if the residual pressure is too low, it'll shut back off...pressure equalizes, the compressor kicks on, the residual line pressure drops too low, it turns off...repeat for as long as the clutch lasts.

The fuel gauge light is interesting, but I'd carry a couple of gallons in the trunk, before summer, and run that sucker down 'till the light comes on or it sputters. I've determined, from driving at low fuel levels, the gauge/sensor is on the left side of the tank, as long right-hand curves have the light go out/gauge goes up a *little* bit, but left-hand ones have it come on/go down. Mine is subtle, but the behavior is there.

I used to long-distance rally a Honda ST1100 motorcycle, with 10.4 gallons of fuel on it, so I've become somewhat anal about gauge/low-fuel light behavior. On that bike, I lowered the low-fuel light's sensor on the gauge assembly, in the tank, by drilling holes about 1/2" lower. That way, when the low fuel light came on it meant, LOW-FUEL. Light = maybe 20 miles, or about 1/2 a gallon.
 
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