Hotter than Hell in S Tex. - A/C Aux fan install ??!!

[parabola]

I've got a brand new OEM Radiator in mine and cleaned the condenser while I was at it - doesn't make a difference here in TX. I'd be interested in a group buy as well, mine works great in motion

Tucker

Same here. Cleaning mine did nothing.

 

[wileetoyote]

So I spent 2hrs going to two different autozones and although both said they had the 14" in stock, neither did. Needless to say I was thoroughly pissed off

Will post pics and results as I make progress.

WET

I finally got to finishing the first half of the project. I copied ToolsRUS setup (thanks a bunch for doing all the homework) didn't take pics cause its the exact same setup). wired it to come on with the AC clutch, added a kill switch, and added a separate aux fan on switch. Here's the premise...

1) AC clutch on , Aux fan on
2) Towing camper up 6% grade, AC off, aux fan on
3) Deep water crossing, AC or aux fan on, kill switch on, aux fan off

The nice thing is when the AC clutch is on, the fan is on. If or when I press the kill swtich, it glows red letting me know the Aux fan is off. If I turn on the Aux Fan switch (assuming the kill switch is off), it glows bright blue letting me know its on. It came out pretty clean. I'll post pics later.

I haven't started on the second fan yet but seems easy enough to do. I haven't decided on which fan I want to use yet.

btw- I used the same bosch relays mentioned earlier (20A continuous/30A peak). They averaged $5 each with S&H.

 

[wileetoyote]

I also wanted to check the difference the single, aux fan makes. I spent over an hour taking measurements and making observations after work today. They are:

- outside temp 103F
- inside cab temp 127F (windows fully closed)
- driving home 71 degrees in the vent

Getting home only 7 miles away, AC had hardly made a dent on the "its fawkin hot (sweaty back and armpit) gage)"

Now at home, AC had been running for about 15 minutes so the vent temp finally dropped to 66F

- garage temp of ~109F
- vent temp 66F with aux fan on (at idle 800rpm)
- turned aux fan off, vent temp settled at 71F after about 15 minutes
- turned aux fan on, vent temp went back to 66F after about 30 minutes
- Revving it to 2K rpm, vent temp settled at 61F

Comparision of '96 Avalon sitting in same garage...

- idle vent temp started at 59F
- revving it to 2k rpm dropped it to 52F

Conclusion...

Here in Phx, the Aux fan only makes about a 5 degree difference on my truck. Maybe I need more freon

Can any other Phx heat soaked LC take a temp reading of their vent temp.

btw - I'm using a digital multi-meter. I compared it to a std thermometer and it was within 1-2~ so it seems pretty accurate.

Thanks
WET

 

[wileetoyote]

I got juked! Both my (previous) posts say 'posts:60'.

shouldn't the second post say '61'?

Sure I get it... "the man" is trying to keep the rookies down....


hmmmm, I wonder what it'll show when I press the 'submit message' button

here goes.... "click"

 

[wileetoyote]

wait a minute.... they all say '61' now...

ohhhhhhhh it auto updates. how clever.

guess I just tallied up two more for nothing. Guess thats one way to do it

;p


Good night y'all


WET

Posts:62

 

[RavenTai]

I take it R1 & R2 are Normally Closed relays? so SW1 (red) is the kill switch? R3 & R4 turn on the fan with AC so long as the kill switch is not closed?
SW2 (blue) is the on switch?

What is the connector on the right side of the schematic between R2 & R4?

That could have been done with less relays (one high current or 2 regular, one for each fan) but that will work just fine nothing lost.

5 degrees is defiantly an improvement but one could wish for more, 109 is a lot of heat to deal with for an idle speed compressor and every bit helps, hopefully this will also help with engine temperatures in your tough conditions. Temps usually max out in the upper 90’s here, highways often pop over 100.

 

[santiagol]

I assume a couple of 30amp fuses have been left out of the diagram. Also a suggestion: wire a 1N4000 diode between relay pins 85 and 86 to drain static electricity that can build up from deactivating the coil.

 

[clarkrw3]

Alright, Im coming over....so you can wire mine!! That is exactly what i want to do! By the way are you going to go to the sonic meet on Friday? I might stop by depending on when my flight gets in but will not be driving the LX for this meet, I don't want to park it at the airport tonight. Thanks again for the write up...and i was only sort of joking about coming over

 

[wileetoyote]

I take it R1 & R2 are Normally Closed relays? so SW1 (red) is the kill switch? R3 & R4 turn on the fan with AC so long as the kill switch is not closed?
SW2 (blue) is the on switch?

What is the connector on the right side of the schematic between R2 & R4?

The 'A' is just a depiction showing that a wire runs between those two relays and continues down to that bottom relay to supply the voltage to the coils of R5 & R6. Thats how R1 & R2 kills power to both 'on' options.

That could have been done with less relays (one high current or 2 regular, one for each fan) but that will work just fine nothing lost.

Yeah, when I went to Napa and went through their relay catalog, all their douple pole double throw relays were $20-30 each. These single pole Bosch 20A continous relays were $2.61 off the internet (waytek.com) but there was a $5 shipping fee and a <$30 order $5 charge so thats how they averaged ~$5. Still cheaper than what I could find but definately a lot more PITA wiring. Oh well.

For those only wanting to wire up one fan using this method, just use 3 relays.

Oh yeah, there are 25A fuses depicted just above each fan (M1=Motor1 / M2=Motor2)

WET

 

[wileetoyote]

:whoops:

Just noticed I drew up R5 as a double pole douple throw relay and there is no R6.

works either way.

 

[wileetoyote]

okay, now for more data.

Took some temps on the way in to work...

- outside temp at 6:30am is 86F
- vent temp dropped as low as 45F and fluctuated between that and 51F as the compressor cycled on and off

My assumption now is that I'm probably not low on freon and that the AC on this LC just plain sucks

Guess I just have to get that second fan installed and see what it does...

btw- One thing I tried doing during my garage testing was watch the temp (thru the windshield) as I sprayed water through a squirt bottle into the fan and condensor to see if that would help. If it did, I was thinking of using a wiper fluid tank/motor/nozzle combo to spray it down when temps reach 115F outside but for some strange reason, it didn't help by more than one degree or so. I'm thinking it just wasn't wetting it down enough. I might have to try that again at a later date with a little more comprehensive test.

WET

 

[97 FZJ80]

WET,

The AC performance test should be done with all the windows open and air temperature difference between the air inleft (garage temperature) and the air outlet at the AC vent. The difference that you've experienced between the LC and the Avalon might be due to the heat soak of the LC from parking in the sun all day.

In the humid Texas heat, if we get >35 degrees temperature difference, it is considered acceptable.

John

 

[Tools R Us]

Good job!

We tried the water thing on the Coleman RV type A/C units we had on our mobile tool trucks. It took lots of water to get any noticeable effect and unless distilled water was used we got buildup of calcium on the condenser and rust in the unit, so that idea was abandoned for better fans.

 

[alaskacruiser]

Thread resurrection: I'm just starting on this project now- my plan is to install an aux. fan with thermostatic and A/C control. Anyone measure the maximum depth fan one can fit in there?

 

[alaskacruiser]

OK guys, I got a Derale fan controller (http://store.summitracing.com/defau...eywordSearch&DDS=1&N=115&target=egnsearch.asp)
that mounts on the radiator fins and has an A/C override, along with a 12" pusher fan installed in front of the condensor. This way, the fan comes on if the rig runs hot (temp setting is adjustable), or whenever the A/C is turned on.

While I did not measure the before/after A/C temps, idle A/C temps are noticeably cooler.

What I did measure was coolant temperature, and I found something surprising: according to my digital gauge, coolant temps rise by 5-8 degrees whenever the fan turns on, even when the A/C is off. So, say the temp is stable at 190 and the fan comes on because of "high temp", the temp will then quickly rise to 195-198. I wonder if the fan is blowing hot air from the condensor into the radiator? Any ideas? In any case, it definitely improves A/C performance, so a worthwhile mod for the summer months.

 

[Tools R Us]

What I did measure was coolant temperature, and I found something surprising: according to my digital gauge, coolant temps rise by 5-8 degrees whenever the fan turns on, even when the A/C is off. So, say the temp is stable at 190 and the fan comes on because of "high temp", the temp will then quickly rise to 195-198. I wonder if the fan is blowing hot air from the condensor into the radiator? Any ideas? In any case, it definitely improves A/C performance, so a worthwhile mod for the summer months.

That doesn't sound right, are you sure the fan is pushing? Increased air flow should equal lower temps.

 

[alaskacruiser]

That doesn't sound right, are you sure the fan is pushing? Increased air flow should equal lower temps.

Yup, double-checked and it's pushing alright.

 

[re_guderian]

Consider washing out your radiator and A/C condensor with an entire $3 bottle of Simple Green and a strong hose (pressure washers might cut fins). I got significantly colder air out of my Cruiser (didn't measure temp) and something like 15 degree cooler air (did measure) out of my Subaru just by doing this. Your fins are coated with grime/dust that insulate them from shedding heat. Clean them to bare painted metal and it may be the best 20 minutes you'll spend this weekend. It's all about that boundary layer of air touching the metal as it flows past. My 93 easily handles mid 90s with barely a noticeable change at stoplights.

DougM

My hose modification to get inside the shroud and push the junk out. This allows you to get the water to all areas of the radiator, not only just in-between the grill cross bars. 2 pieces from HD, and cut off the threaded ends of the 90 degree part, and it fits nicely around the fan inside the shroud...


edit: just don't stand directly in front of where you're washing...

 

[-Spike-]

Update: AutoZone no longer carries this exact fan, although the part number is the same. The good news is the new unit is higher quality, at least higher than the one older style unit I was able to locate. The new unit has a permanent magnet motor and a balanced fan blade assembly- it had weights on 2 blades (I was impressed that they went to the trouble), the old one I found was a brush motor and wobbled badly which made it vibrate enough for me to think it might rub a hole in the condenser eventually. The bad news is that the new one costs more now at $99 and won't fit, at least not without some creative bracketry. The 4 mounts for the zip-tie style attachments are situated in such a way as to make it impossible to get all 4 over the condenser- either the top or the bottom two holes hang over, and it can't be mounted sideways either. The old style has like 10 holes for mounting, so you can pick four or more that are suitable. Pep Boys sells a similar fan to what ToolsRUs used, made by Hayden, but it looked crappy too and didn't fit- it has issues with the center core support bracket. I'm looking for another option, possibly from NAPA- they sell the Flex-a-lite brand which looks to be good quality, and of course is priced accordingly. I need to go back to NAPA and look at them again, now that I know what I'm looking for.

If you care to try the fan ToolsRUs used, the old style fan I found came in a white cardboard box sporting only the blue label pictured below. The newer one came in a flimsy blue box with pretty graphics all over it, and the part numbers were swapped- '733690' was printed large after 'P/N' and the '226114' was smaller and to the right- just the opposite of what is pictured below. Also, the '050608' was completely different. If you find one, just power it up before you install it to make sure it's not way out of balance- it's very possible I found a lemon.

-Spike

Mounted one on brother Rob's '97 today. Found a 14" at Auto Zone sold as a TorqFlow brand for 69.99, did a little research and it's a Derale #16514, http://www.derale.com/electricfans.shtml great price for that fan!

This is the biggest fan that will fit, it's a squeeze but only required bending one tab out of the way and bending the horn mount slightly to clear. Had to pull the right headlight, fan and clutch, the right side and left upper radiator bolts so it could be pulled out on the right side to get the zip holders through the condenser. We bought an extra pack of the zip holders and used six with the supplied foam pads on the radiator side and put 3M double stick foam tape on the fan to keep it from shifting, it's not going anywhere!

Wired it up with a 25 amp fused wire from the battery to a 30 amp relay mounted between the washer bottle and aircleaner duct on the fender well. The relay is turned on by power tapped from the A/C clutch, so the fan runs with the compressor.

The total cost was about $90, it made about a 10 degree difference in the idle vent temp sitting in the shop, we will see how it works in the real world.


Auto Zone box label.

 

[clarkrw3]

Let me know spike if you find the perfect fan at napa...I need to do this soooo bad.