Anyone running a grill block read this one

[benfrogg]

So, a mod I've wanted to do for a while now actually happened today. I installed an LED indicator wired to the positive lead coming from the radiator cooling fan.
Why, you may ask?
I just put my "plug" into my already 80% blocked grill making it more like 95%. Ambient temps here are 50 df or less and are getting colder by the day. I figured all was well. The temp gauge has never shown any problem.
I wanted to know if, when, and for how often/long the fan was running. The results were surprising.
For the first ten minutes of my drive no fan at all. After the first ten, the fan cycled on and off every minute or so for about 25 seconds. It was on longer on hills. It was also coming on more frequently and staying on longer the faster I drove. After pulling the "plug" on my grill block, it ran only once in 35 miles up a really good hill with a load in the back seat.

So, other than the obvious power it takes to run the fan, and the potential for engine damage, what's the other concern I have?
I don't know if this is a problem in my car, but I be it would be a problem for more modern cars. When that fan is running frequently or all the time, I'm wondering if the ECU retards ignition timing and other potential changes that could decrease engine temp at the sacrifice of efficiency. Any honda guys know if this is possible in the VX? I've heard of it being the case. If so, retarded ignition timing would reduce efficiency gains from the grill block.

All that being said, it took 20 minutes to install this LED. It seems like a no-brainer for anyone with a grill block.

Next project is to replicate what someone on ecomodder did and make a "choke like" adjustment for the "plug." Then I can use a choke cable in the cabin to open or close a door in the front of the grill block.

B

[slurp812]

Originally Posted by benfrogg

So, a mod I've wanted to do for a while now actually happened today. I installed an LED indicator wired to the positive lead coming from the radiator cooling fan.
Why, you may ask?
B

I have one too, and for the same reason! I can get away with my partial grille block in the winter months, but no way in the summer. As a bonus at highway speeds mine will come on dimly to indicate that the fan is spinning due to air pushing it at speed.

[GasSavers_WD40]

hey benfrogg could you show me where you wired into for the LED, I tried this same thing with 3 different LEDs and they all died within a day.
So I don't know if its my wiring or just bad LEDS
Thanks in advance Dennis

[benfrogg]

I took a ground from a sheet metal screw into the body near the led. I unplugged the fan at it's connector (sandwiched between the bracket and coolant container) and put a multimeter to ground to find out which one was ground. The brown with some kind of stripe was my ground. I used a wire tap to tap into the other wire and ran it all the way to cabin led positive side.
Job done for now. I suspect I'll have to put a relay on it in line because I think LED's are sensitive to varying voltage. After the 12v from the ecu happens, the fan slowly slows down and makes the led dim then shut off. I've got a feeling the led won't take that for long and it's probably what's going on in your situation.
Use a relay from a 12v source elsewhere. Cheaper LED's probably burn out more rapidly at low volts.
Just a guess.
Also, make sure you have a good ground.
B

[GasSavers_WD40]

Awesome .. thanks for the info .. let me know how long the LED lasts for you.

[pgfpro]

On the Honda VX ECU's ECT Corrections there isn't any ignition-timing offset change from 168* to 250*F

On the Injector Battery Correction theres is some change when voltage changes but the factory is as good as it gets and wouldn't be a issue.

But like you said a good adjustable grill block would be a better way to go.

[basjoos]

I have an LED connected to the radiator cooling fan and use it for adjust my radiator door as I am driving so the fan kicks on occasionally. I start a drive with the radiator door closed, open it partially 10 to 15 miles down the road when the LED comes on, then adjust the amount of its opening on the rest of the drive as needed depending on engine load, air speed, and outside air tempoerature.

[GasSavers_BEEF]

as far as the LEDs burning out, why not throw in a current limiting resistor? that way, it doesn't burn up.

I can't say what value right off hand but it shouldn't take that long to figure out.

[bobc455]

I would think that if the fan is coming on, your grill block is counter-productive.

I have an old '69 Buick (as opposed to a new '69 Buick, I guess) with electric fans. I would drive the whole way to work (45+ miles each way) and the fans would never have to come on. And that 455 would generate a lot of heat!

-BC

[DRW]

I noticed the same thing; my grill block causes the radiator fans to come on more, which keeps the engine cooler than I'd like. I use a daring approach and unplugged the radiator fan switch!

Of course I have a back up plan. I wrote a little bit of code in the ecu that turns on the CEL/MIL when coolant temps reach 223*F, and I have a dash mounted fan switch. I've been meaning to hijack one of the ecu outputs and use it to turn on the fan relay when the engine reaches a certain temp, but my current approach has been working fine for 3 years, so there's little motivation to automate the fan switch.