DC Fan Controller Users...In Here Now...Help!!

[FobraR]

okay so I have everything set up and motor is running HOT. Here is what I've got that makes a diff in cooling:

no radical motor just warmed up stock block (cam, al heads, 12 deg timing)
+30% water pump
March underdrives (crank & water)
Taurus 3.8 2spd fan (wired to high)
DCC fk35
3 row radiator - not aluminum
180 stant t-stat

Heres how I had the controller setup:
-hooked to constant power for cooling after shutoff
-temp probe is in fins at middle of lower rad. hose
-jumpers are at stock 180 setting


temp guage at idle is half way...with mechanical fan it was just above 1/4
driving around block <5 miles guage went up to 3/4 or a shy more babying it the whole way.

What do you guys have your controller settings at if you have similar setup?

 

[PoopDawg]

What "gauge" are you going by? The stock one? If so, you are chasing your tail. Mine will read all the way hot, but it's actually at 180 degrees (with my autometer). Get a real gauge then come back and tell is what's going on

 

[FobraR]

I know the stock guage isnt accurate, but the t-stat, guage, and temp sensor havent changed so why is it now showing sooo much hotter. The stock guage can't just be put to blame.

 

[PoopDawg]

Actually it can be. I replaced everything in mine, including the CLUSTER, and I still had the same problem. Get a real gauge, then come back with the problem.

 

[FobraR]

I've got a SnapOn digital temp gun, so i'll use that on a few different areas. But I'm not gonna go out and buy a new gauge setup for this.


Does anybody have any setting suggestions for the controller and my setup or if I should move the temp probe somewhere else?? Thats what I need

 

[jrichker]

Temporary solution to tell what temp the engine is really operating at:

Probe the ECT (located in the heater feed tube on the passenger side) with a couple of safety pins and your handy DVM. Black lead on the DVM goes to the black/white wire, red lead on the DVM goes to the green/yellow wire.

Pin 7 ECT signal in. at 176 degrees F it should be .80 volts

Here's the table: The values are +/- 15%, so don't get worried if your readings vary a little bit.

Voltages are measured across the two connector pins of the sensor with the sensor connected.
68 degrees F = 3.02 v
86 degrees F = 2.62 v
104 degrees F = 2.16 v
122 degrees F = 1.72 v
140 degrees F = 1.35 v
158 degrees F = 1.04 v
176 degrees F = .80 v
194 degrees F = .61

Ohms measures at the computer with the computer disconnected, or at the sensor with the sensor disconnected.
50 degrees F = 58.75 K ohms
68 degrees F = 37.30 K ohms
86 degrees F = 27.27 K ohms
104 degrees F = 16.15 K ohms
122 degrees F = 10.97 K ohms
140 degrees F = 7.60 K ohms
158 degrees F = 5.37 K ohms
176 degrees F = 3.84 K ohms
194 degrees F = 2.80 K ohms

Once you know the real temp, you can go from there.

 

[srothfuss]

The stock gauges are just not reliable for taking any type of reading.

The DCC unit will keep the motor cool for sure.

 

[FobraR]

Thats the kind of response I'm lookin for. Thanks Jrichker that helps a lot. Now if I can only get ahold of Brian Baskin...

 

[PoopDawg]

Now if I can only get ahold of Brian Baskin...

Good luck!

 

[HISSIN50]

Does your fan come on at all?

Good luck.

 

[TheUser]

I do agree that the stock gauge might not always be accurate (although my 91 has an Autometer mechanical and my stock gauge showed the same temp, so stock gauges aren't always bad). I do understand that the variable here is the fan setup, not the gauge (same gauge w/ both fan setups), so I see your point.

Like HISSIN said, is the fan coming on? Is the thermostat opening? Use the info Jrichker posted and check the temps and see what temp the fan comes on at (and also eliminate the occurance of a faulty gauge). That's what I did to make sure mine was working correctly. Mine is setup exactly as yours. Your fan should be set up for the thermostat you have, so I think you're correct w/ your settings.

When my fan comes on, the temp drops like a rock

 

[Black Sun 5.0]

How was the temp before you switched to the DCC? Did you also get the LED light to tell you how much juice is pushing through the DCC? I agree that the stock gauge may not be accurate, but what was going on before the switch? If it worked just before the switch over, it should still work now. I'd still get an after market gauge.

 

[FobraR]

Yeah the fan does come on, but seems like a little late, or it isnt getting enough power from the controller. The t-stat is also opening for sure too.

Before the switch temps would be 185-190 under normal driving and idle. Now with the electric fan temps are at ~210 idle and shoot up to ~230+ under normal driving.

When I had the mech. fan I would only see ~230 if I was driving 'very spirited' for lengths of time.

I'll try dropping the temp setting on the controller and set it to 10% minimum fan speed at all times too.

Oh yeah about the LED, no, but which pins does it plug into on the controller? What are pins 3,4 and 15,16 for? Does any know if it matters which way the temp probe is plugged into pins 1,2?

Thanks guys!

 

[HISSIN50]

I'd double check the probe to make sure it's inserted far enough and making good contact.

Fan polarity correct?

The LED connects to the output terminal on the controller, as I recall.

I dont think Pins 15 and 16 are used (for our applications anyhow), but I use a rheostat instead of jumpers, so I cant remember.

Good luck.

 

[FobraR]

Polarity is correct, I checked multiple times. I'll try different spots and depths on the temp probe.

 

[sgarlic]

Yeah the fan does come on, but seems like a little late, or it isnt getting enough power from the controller. The t-stat is also opening for sure too.

Before the switch temps would be 185-190 under normal driving and idle. Now with the electric fan temps are at ~210 idle and shoot up to ~230+ under normal driving.

When I had the mech. fan I would only see ~230 if I was driving 'very spirited' for lengths of time.

I'll try dropping the temp setting on the controller and set it to 10% minimum fan speed at all times too.

Oh yeah about the LED, no, but which pins does it plug into on the controller? What are pins 3,4 and 15,16 for? Does any know if it matters which way the temp probe is plugged into pins 1,2?

Thanks guys!

Ok, all the questions related to the DCC can be found on his site (dccontrol.com) then click on Fan Control twice and you can find the install sheet. This explains what all the jumpers are for.

If you look at the temp probe plug, one side says 1, and one side says 2. I always line the numbers up. Speaking of the temp probe, do you have it where it needs to be? You said middle of lower hose.. which confuses me a little, but it needs to be basically right next to the lower hose, and needs to be pushed in all the way until that little lip on the probe is flush with the fins. It's further than you may think.

 

[baskin]

Check to see if it’s actually coming on late or if it’s starting at the correct temperature, but not ramping up enough.

If it’s coming on late, and you’re sure the thermostat is open, the most likely problem is that the sensor doesn’t have a good thermal connection to the radiator, you’ll also typically see an overshoot in temperature and then a corresponding overshoot in fan speed if this is the case. The ridge at the back of the sensor should be flush with the fins and should be on the engine side of the radiator You can verify the thermostat opening by leaving the cap off and looking for coolant flow.

If it starts at the right temp, but doesn’t ramp up enough, it could be a number of things, start by verifying that the controller will provide the current by waiting for the fan to start running and then turning the AC on, this should give you close to full fan speed and then ramp down to 50%. I’ve also had a few people use 15/16 instead of 1/2 for the sensor and that will cause the fan to not run full speed. 15 / 16 are connected to the yellow and blue input wires, 3 is a sample of the output and 4 is ground

 

[FobraR]

Where is the best/most common place to get a switched Acc. wire under the hood near the battery? Right now I have it hooked up to constant 12v for cooling after shutdown, but I'm not able to use the 10% min feature due to this.

 

[jrichker]

Where is the best/most common place to get a switched Acc. wire under the hood near the battery? Right now I have it hooked up to constant 12v for cooling after shutdown, but I'm not able to use the 10% min feature due to this.

Tap into the red wire on the low coolant sensor mounted on the overflow tank.

 

[grego37]

slowing down the waterpump with underdrive pulleys will allways make a car run hotter.The few horsepower (if any) you gained by installing the overdrive pulleys will turn your waterpump slower.
March fails to advertise that.
most people with street strip cars or hot rods will do the opposite and overdrive the waterpump for best cooling