617A electric fan - your setup - Page 6 - PeachParts Mercedes-Benz Forum

ah-kay · #76 01-31-2015, 11:22 PM

Quote:

Originally Posted by Tmadia

The price is great but I wonder if they have any with a little less hysteresis.

This is a mechanical forum. I am not sure how many members understands all these PWM, hysteresis terminology. Hysteresis is the switching band and 15 degree is good. You do not want the switch to ping pong if the band is too narrow.

I think it is a good design to 'COMPLIMENT' the clutch fan for cheap. As I have said, a well design cooling system would NOT need all these BS but I use it as a backup just in case the clutch fan fails or the radiator is clogged. It is your car, so you decide to do whatever is right.

cho · #77 02-02-2015, 08:29 AM

Quote:

Originally Posted by tjts1

82c temperature switch: 61311364274
This has a 14mm x 1.5mm pitch thread, identical to what MB uses on the OM603 and likely OM617

71c thermostat: 11531713040
I think the one I have a Behr brand.

or we can go with bmw 61311364272 (91C) with default behr 79C/80C tstat
...correct?

.

funola · #78 04-28-2015, 01:47 PM

I have a bunch of small temperature cut out switches from a Beckett oil burner conversion to WVO project used to control a heating element. I ended up not using them and went PID/ SSR for better control so they came in handy. These are normally closed, most are around 165 F but 2 were more suitable @ 185F and 195 F. Since they are normally closed I have to use an extra relay in order to control the aux fan relay.

I glued one of them to the front of the thermostat housing and the other to the rear closer to the EGR valve as in pic. Unfortunately I lost track of which switch is where (they are unmarked, I only know the temps by testing them with a digital PID temp controller heating up a cup of water).

The test consists of getting the car up to temp and let it idle till the aux fan come on. The front switch I let the temp climb to a little above 90C per my 85's 300D's temp gauge and the aux fan never came on so I aborted the test and switched to the other temp switch near the EGR valve, which turned the fan on at 90C (195F) on the gauge. I let it idle for 10 minutes and the temp stayed at 90F and aux fan kept running (temp did not continue to climb but didn't drop either). Test was done at around 60F ambient at idle. With the aux fan on for a few minutes, the radiator directly behind the aux fan was cool to the touch. I'll be doing more tests in stop and go driving when it gets hotter to see if the aux fan alone is sufficient for engine cooling. If not, I'll add an electric puller fan.

funola · #79 05-17-2015, 07:55 PM

It's been cool, in the 70's the last few days but it got up to 87 F today. I added 2 cans of R134A and the AC cools again. Went for a test drive in stop and go traffic with the AC on, with just the aux fan for cooling, blower on high, vent temp 48F. Coolant temp gauge never climbed past 90C (194 F) even with the car idling for a few minutes- it stays solid at 90 C. See this video https://youtu.be/LElmpqkSyUw

The only thing I didn't like was with aux fan and HVAC blower on high (that's about 32 amps total), charging voltage was 12 volts which means the battery was not being charged.

I will continue testing in hotter weather. Will start looking for an elec puller fan so I have a back up.

Hit Man X · #80 05-29-2015, 11:20 PM

Cool thread guys! Pun intended.

I stuffed a Volvo S90 fan (same as the mid '90s 960) dual speed fan under the hood of my SD as the clutch died.

It is tight but clears with plenty of room. I am using the OE Volvo two speed relay as they are very durable... the one on my 11/97 V90 finally died 18 months ago for the low side, high still worked (I flipped pins on the relay until the new one showed up). Even on low, it moves plenty of air. Mine has never come on high speed in the V90 during normal use...even let it sit at idle during the summer here in Texas with the A/C on without going to high speed. Only time it popped on high was when the temp sender to the ECU crapped out so it went to high mode as default to protect itself. The V90 also comes with a 100A alt only and a 30A relay in the fuse box.

Planning on using the BMW 91°C/99°C temp switch and plans are to install it in the thermostat housing. I am still working out final fitment of the shroud but once complete, will snap photos.

The Volvo relay just grounds to flip the fan on from the BMW swich. Super simple, no electronics needed aside from relays. And if you are paranoid, just carry a spare fan switch and spare Volvo relay...cheap enough. I have probably $60 into this at this point.

I have the AL129X on the SD currently so should be fine with idle voltage as I cannot imagine the two speed Volvo pulls more than 20A at idle once running.

Oh also, this is the 30A Bosch style relay pin out to make the fan turn on at low speed with a 12V trigger from A/C compressor.

85 - 12V from compressor
86 - Ground
87 - Hook to low speed pin on Volvo relay along with the 91°C wire from the aforementioned BMW switch
30 - Ground

Tested this out on the bench, works great.

jupel · #81 10-18-2016, 03:25 PM

Quote:

Originally Posted by kestreltom

If your old Mbz cools just fine, then feel free to ignore the following:

Close-up of the controller:

Link to DipTrace and here are the files and instructions.

Hi Kestreltom!
I'm very impressed by your fan controller and i want to try make copy for my w124
Can you update your google disk link, because it did not work.

jupel · #82 10-30-2016, 03:06 PM

Quote:

Originally Posted by kestreltom

If your old Mbz cools just fine, then feel free to ignore the following:

See this link for a demo of a variable proportional controlled electric fan.
http://youtu.be/i6go2VTr5bY

Here is what the fan looks like - the silver colored rectangle with barcode is a dc variable speed controller:

Close-up of the controller:

Link to DipTrace and here are the files and instructions.

Look at the evidence: the 80's era Mbz viscous fan hubs fail almost universally. Failure mode takes place in the form of the widely observed inability of the viscous coupler to "engage" at elevated radiator air discharge temperatures. Lots of "fixes" have been implemented over the years by committed die-hards.
My own situation produced a legacy of frustrated attempts to produce better cooling. Since I live in Albuquerque, have performed power upgrades on the engine, and need my A/C system to work well, I have been motivated to find a solution that really works.
My first attempt involved replacing my fan with a bigger solid mount aluminum fan from an 80's vintage 380 SEL v8 sedan. That fan produced excellent cooling, but literally sapped so much horsepower, that I had trouble accelerating uphill. I then tried injecting silicone oil into my oem viscous coupler, but got no results. I then tried modifying another viscous coupler from a later 450 sel to incorporate a temperature sensitive bimetallic element that would engage/disengage the fan at a certain temperature, but found that I could not adjust it properly and easily. I then tried injecting another newish oem viscous coupler with a much thicker silicone oil - which worked, but essentially locked up the coupling mechanism, which worked OK, but sapped more hp than was needed for cooling.
At this point, I have replaced the radiator with a new racing crossflow unit, installed a Mbz temperature sensor on the cool side of the radiator, will be replacing my fan & coupler with the electric unit referenced above, and finally upgrading my alternator.
I have already done all the basics such as a citrus flush, using a vacuum airlift to fill the system with fluid, etc...

can you update google disc link, please