posted by
someone claiming to be Mike
on
Wed Feb 1 19:48 CST 2023 [ RELATED]
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I am familiar with what the fan clutch does and how it activates. What is the electric fan in front of the condenser for - my A/C is not working so am planning on removing the condenser and fan for better air flow through the rad. (My mechanic feels it should stay as it will protect the rad. I also have a 1980 - 245 no electric fan or A/C and have not had a problem with rad damage from stones). Where does the fan connect to?
Also down the road thinking of getting the compressor by-pass bracket from IPD to get rid of the extra load.
Any thoughts from those that have done this?
Thanks
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I don't have a proper Volvo wiring diagram for your '93 Volvo Classic. People have searched online and not found a copy, so I'll try to advise you here using my best guess of how it operates based on 700s and 900s of similar vintage with LH 2.4 (which I believe is what you have, only manual trans of those years got LH 3.1). Art Benstein here knows those late model 240s as well as anyone so may wish to chime in here when he sees this.
Re. A/C compressor. The ipd compressor bypass bracket works well and many have done it, some have fabricated their own. Having said that, leaving the compressor installed places negligible extra load on the engine and the added vehicle weight is also negligible. The clutch is freewheeling and will not engage unless there is refrigerant to activate the low pressure switch. During heavy acceleration there is a tiny bit of extra load overcoming the initial inertia getting the clutch spinning, again negligible for practical purposes. Leaving the compressor in place allows a future owner to try resurrecting the A/C system. With effort and $ it can be still done. You're apparently lucky, according to Dave Matthew's site, your 1993 system is R134, while up to the previous 1992 model year the 240s were still R12 and needed a conversion kit (no longer available from Volvo, but can still be done for $$). Leaving the compressor and belts in place and being opposite the power steering pump in theory helps place a more balanced force on the crankshaft and harmonic balancer, not that it's any kind of real problem.
Now as for accidentally using your A/C dash switch, there is no need to disconnect it. If A/C is called for using the dash switch then normally there is a delay so the compressor won't kick in and out every time the dash switch is flicked, also giving the ECU a chance to not have to constantly be chasing maintaining base idle every time the compressor is engaged/disengaged. This is accomplished using a delay relay on the line between the switch and the compressor. In the 240 A/C systems, the A/C switch is a separate dash switch and is not connected to the ECU. The ECU has no idea that A/C is being called for other than when the compressor engages, which does have a signal that gets passed back to the ECU in order for the ECU to raise base idle a bit to compensate for compressor load. With a non-functioning compressor, disconnecting the A/C switch accomplishes nothing other than keeping the red indicator light off. BTW, removing the delay relay accomplishes the same thing as disconnecting the dash switch (it's at the other end of a wire). Like leaving the compressor in place, leaving the delay relay in place allows a future owner to more easily resurrect the A/C system.
FYI to others following this, in 700/900s the A/C switch is in the integrated heater control panel. In the early 700/900s with a single speed electric fan (there is no clutch fan), the story is the same as described above for the 240s, disconnecting the A/C wire from the heater control panel or removing the delay relay accomplishes nothing. Now for the later 900s with a 2-speed electric fan, the story is a bit different. The A/C function in the heater control is connected to the ECU and could in theory affect fan operation and base idle under certain conditions. In those systems, the delay relay was eliminated, the ECU controls the compressor and does the compressor delay to prevent kicking in and out rapidly. The thermal coolant fan switch in the rad that controls the electric fan was also eliminated and now controlled by the ECU using the block temp sensor and knowing when the compressor is engaged. Knowing that A/C is being called for at the control panel (such as in Defrost mode), the ECU may momentarily raise base idle a bit in anticipation of the compressor kicking in. It may also cause the electric fan to operate more frequently on low speed when the block temp rises. In that case, disconnecting the A/C wire between the heater control panel and the ECU makes a bit of sense when the A/C system has failed, but the difference is minimal.
Re. auxiliary electric fan, a similar story, leave things as they are. On 240's with an auxiliary electric fan (or 700/900s with a single speed electric fan) the fan is operated by a thermal switch in the rad. Leaving the electric fan in place is of benefit as it provides additional cooling in extreme operating conditions (including low coolant level). As others mention, it has minimal affect on airflow and certainly not on engine operation. The only affect on operation is placing an additional load on the alternator, but again, if the electric fan is operating, it's for a good reason whether or not the A/C system works.
Some 240 people have removed the clutch fan and switched to total electric fan cooling. The clutch fan does place a very small increasing load on the engine as the clutch engages with increasing rpm and temperature. If your auxiliary fan moves the same amount of air as the 700/900 single speed electric fan and the rad core is of the same capacity then you may be able to do it now, simply removing the clutch fan, but you'd have to worry about the drive belts, same as removing the compressor. If the rad or fan is of insufficient cooling capacity without the clutch fan then upgrading to a better electric fan may be needed. I recall way back when I was considering converting our 240 to electric fan, of seeing a few articles and posts on fan conversion. With some google searching I'm sure there are many others since then. I'll be interested if anyone following here has done the conversion.
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Dave -still with 940's, prev 740/240/140/120 You'd think I'd have learned by now
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posted by
someone claiming to be Mike
on
Sun Feb 5 07:11 CST 2023 [ RELATED]
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Thanks for the detailed info.
I replaced the old fan clutch - rusted bolts and likely not working - was the original Aisin.
I replaced with the Asian tropical unit which comes on earlier.
So how does it function differently than the electric fan?
Are they both intended to keep the temp needle at 9 O'clock.
Thanks for clarifying
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Hi,
You have had a lot of responses considering the waning of the 200 series tab.
Thanks for asking good questions.
As far as the needle staying horizontally on the gauge that is done by a 92 Celsius thermostat installation.
The most reliable and precise one is now made by Borg Warner under the Wahler branding for years.
I’m partial to them because the unit is made of brass and copper so the whole unit moves with its like material. Brass has copper in it and so forth plus they date them so you know how long it’s been in the car. I have use then for many years in just one car so I know they hold up and up!
I only buy used cars and with that have experience with the other brands failing.
On cars with the electronic speedometers, not cable driven, the instrument cluster come with another gadget that is known to fail to give incorrect readings, as it works in increments of digital steps. Not an even up and down movement. Not like the analog gage it’s attached to.
It anticipates the temperature and does not show a true reaction to what the temperature is all the time.
It has gotten to be a standard procedure to bypass the electronic board or remove it all together and jumper the pins with one short piece of wire. This way the gage works directly with the sender.
Early customers new to the 200 series Volvo got discombobulated.
Apparently that made it a big deal from the from Volvo’s service departments to sales.
Then VDO the makers of instruments and the electronic speedometers rubbed their hands through their young hair to create different and supposedly better clusters over the cable drives.
Maybe, but the compensation board was an extensional root to where electronics was going in later cars.
Story here:
Today if something fails in a chip it’s a boondoggle trying to get it fixed.
I have a friend with a TOYOTA Tacoma. The cluster throws CEL’s claiming a bad speed sensor but the truck works fine and sensors are fine. It’s in the cluster itself.
I check it out as much as I could and found nothing. It had dealerships written all over it!
I checked into getting a rebuilt for $150 plus S&H, turn around leads and the down time for the vehicle.
The mileage has to be programmed exactly over onto the new one before it’s sent back according to the rebuilder.
She didn’t have the money or could do without the truck. So it got on the back burners from over a year ago.
Now she is having it done in a local garage and the cluster got sent away.
The truck has to sit around the garage. I guess it won’t run without the cluster connected.
It’s now been two months because there are NO programmable chips available.
I’m still waiting to see if she ever gets the truck back. Luckily, her roommate has put her on her insurance plan and they can still get around in her car.
Toyota has been out to lunch on the whole affair.
Even under recent newer vehicle warranties in dealing with instrument cluster failures.
The chip thing is still going on with todays cars, even with many manufacturers and other than vehicle types.
The USA may have gotten to fancy with buying special this or that. Is finally getting an overdue wake-up notification with an orchestra of chimes! Of course with computer generated tones! (:-)
As far as the tropical fan clutch over the normal street model I haven’t tried one.
If it moves more air it’s going to be more noisy at any time.
If just comes on sooner due to A/C and traffic then an electrical one works just as well. Around the late eighties the 200s came with auxiliary fans and a larger heat exchanger inside.
The upgrading through the model years was due to the changing over of refrigerants to a ten percent less efficient R-134A.
Today it’s R-1234 YF. Yell Fire! Europe’s Mercedes or the Germans fought our EPA.
Now that’s another controversial corporate & governments boondoggle.
Maybe the EV’s will turn it all upside down again.
Despite the 93’ being unique in it own ways, from the previous years, it can accept changes with grace.
Phil
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interesting article Dave. My 240 and both my 740's have it but it's not really very necessary here in Vancouver so the most I do is recharge it but it only lasts for a short time, often the same with the hot weather. the last few summers did have long hos spells so maybe the changing weather patterns are a reason to keep AC intact.
I often wonder if it may be nice to utilize the location and instead mount a second generator that could top up a second battery for things like using a 120V invertor to run power tools, lights, stereos, maybe camping use etc. In RV's they often use a solenoid or diode something to assure the battery can recharge but not discharge the car battery.
I suppose that would also equalize this crankshaft balance issue but I dot know if that has much validity. Cars without AC dont seem to have more issues with the cranks and bearings failing prematurely, or do they?
I think my 240 has the alternator on the passenger side of the block but on my 740's its on the drivers side. The engine is the same. it might be possible to claim a 240 alternator bracket to mount as a second ( or the reverse) because it is made for either side of the engine, depending on the model. If that's true it would pretty much be a bolt on option. you may be able to fit a higher amp alternator but many of us have spare parts around so this may not be much of an expense.
another fun option may be to use an air compressor and have a tank in the trunk for air tools. I dont know if a AC compressor can work like a standard air compressor in this way or not. I think some like with trucks mounted welders and such may do this so they have on board compressed air available, as they tend to use them like portable workshops.
those thermal switches can probably be tested by dropping them in a pot of water with a thermometer connected to a meter to see when they open and close. I htink they do go bad and may become inaccurate.
In my 88 ford van I'll often hear a relay or the compressor kicking in and out repetitively. I don't know if that means it's low on refrigerant or not.
some compressors work by using a V 8 and using maybe 2 of the cylinders as the compressor. It would require a tricked out cam and manfold mods, but the theory is the engine can run on some cylinders and use the others as the compressor. I always found the concept interesting. I wonder how well that can work on a 4 cyl. they can run quite well on 3 cylinders with a plug removed.
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Hi Phil. Our temperate climate out here certainly does allow us to get by without A/C. One of the problems this creates is not using your A/C enough to keep the seals from drying out. For example, with my parents '89 240 I helped them buy new, they never ran the A/C unless absolutely needed, so it got used barely once or twice during the summer, I suspect sometimes not even that. Despite my cautions, it soon lost refrigerant and stopped working. That was over 25 years ago. My brother now has the car and it's still that way, never been recharged. Being in Vancouver he says he doesn't need it. The cost to now convert it to R134 is now almost prohibitive in this mild climate, especially as the Volvo conversion kit is no longer available.
One advantage in the 700/900s is that the A/C automatically comes on in Defrost, so does get continually used in the winter whether or not you want it. On our wet coast, foggy windows are not at all uncommon, even frosty windows if you park outdoors. My 700/900 A/C charges have lasted reasonably well. I now have a slow compressor seal leak in one that requires a recharge every 3 or so years, which I can certainly live with until I trip over a free good compressor. Even if the A/C is working at 25%, that's almost adequate in our climate, except maybe the couple of scorchers we've had these past two summers.
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Dave -still with 940's, prev 740/240/140/120 You'd think I'd have learned by now
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i'd get a wiring diagram and wire the fan to work. besides, the design is such that any decrease in airflow is minimized.
i had a 78 w/ac and wired a fan onto it. a temp switch in the top radiator hose and wired to the ac so it would come on with it on. never got above 9 oclock on the temp gauge. the switch came on as the needle got above 10 or so. 90c, i think.
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