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I've been buying from jimellis online. Their web page and service has treated me well so far. I've watched the local guy fail to find a part in the system that I know for a fact is still available, and he just did a google search for generic non-OEM parts, so I stopped going there.
So my fan setup is kinda unique. I have the fan wired to a Derale PWM controller that is getting its source power off the original fan power wire just on the back side of the relay. The controller has its own temp sensor so i just want it to have keyed power all the time when the car is on which i thought i achieved by doing the below. The issue is that the fan isnt working. i checked the wiring and it led me right to the relay not getting power across. tested the fan with a jumper wire and it works fine. Are my settings below off base or do i just need to replace the relay to be happy again with a fan.
Edit: Added wiring diagram. In theory couldnt i disable the MS3 and ground the B/W wire for constant keyed power and have it work?
Last edited by matrussell122; 06-19-2018 at 10:28 AM.
Can you explain the mechanics behind that? Im not disagreeing just want to understand better. So if i ground the B/G or R/G to the chassis the relay will give me constant keyed power? It seems like that would just give me power all the time?
For one, B/W is the 12V source for the relay coil, so grounding that would just have the relay off all the time, because B/G or R/G is a ground signal from the ECU. If you grounded B/G or R/G, you now have 12V differential over the coil, thus the relay is active. B/W is 12V in start or run, therefore if B/G or R/G is always grounded, then the relay is active whenever B/W has 12V, which is only in run or start. When you turn the key to run, the relay has power, and then your temperature controller determines if the fan is actually on or not.
That makes a lot more sense than what i was thinking. I thought the power source was going away from the ecm. Is that why there is an arrow pointing towards the ecm in the doodle?
Is that why there is an arrow pointing towards the ecm in the doodle?
Yeah, you would also find that wire continued on the ECM page, which would go directly into the ECM. ECU's are always (except for special cases) ground switches.
I tested the relay on my lunch break and i think it is bad. I tested by hooking the two coil pins to 12v+ and 12v- and got zero ohm reading between the two other pins. That would indicate it is bad correct.
I tested the relay on my lunch break and i think it is bad. I tested by hooking the two coil pins to 12v+ and 12v- and got zero ohm reading between the two other pins. That would indicate it is bad correct.
Zero ohm or zero continuity? Because when the coil is activated, there should be near zero resistance (ohms) between the two switch pins. They would be open when the coil is not activated (infinite resistance, same reading you'd get when the probes aren't touching anything). Easy way to know is if you put the multimeter on the two switch pins (two that are not the coil), does the reading change when you give the coil pins power/ground?
Was measuring in ohm not cotinuity. The reading does not change when powered or not. Also when the two coil pins are powered i do not have cotinuity. It all just clicked in my head. Picking up a new relay in an hour and will report back. I think that should work.
Last edited by matrussell122; 06-19-2018 at 02:13 PM.
Replaced relay with the horn relay (same relay) and ordered a spare. Fan works like a champ again.
Also to help cure my random bouncing idle i bumped my Idle valve 3pts for the CLI and adjusted my CLI settings to adjust more aggressively so we will see how that works on the way home.
Well melted the replacement relay on the drive home. Used the one from the horn spot until the new one arrived. Not that it matters now since the plug is toast. The power supply to the relay is what started cooking everything. Think I'll have to run all new wire from the battery to a new external fan relay now.
After further investigation most all of the wiring is good. Just the wiring just outside the relay is a little screwed up. Going to replace it with an external fused relay rated for power draw up to 70a that I added a picture of below. After more research on my fan choice it seems people are getting up to 68a spikes on startup and having the fan settle down to 27ish amps. Since I am running the pwm controller i dont ever see the 68a draw on startup but am most likley hovering right around 30a continuously. Cant complain about the fan though since it is great and flows upwards of 4000 cfm.
Got my fan wiring all sorted out for the summer and should be getting some goodies for a parallel project to go with the new motor. Now that i have a bit of time to focus on what ive wanted to is the CLI sometimes doesnt catch. It happens more when its up to operating temp. The last minute or so of the attached log is where the problem is happening. There are times where it wont catch and drop to as low at 300 rpm or even die all together. Im sure its something obvious that im missing i just cant seem to find it.
The ones I got are the advance autosports naca duct window so always open. Just screwing with a duct on the freeway in my truck was significant air flow. I will install tomorrow on my lunch bu Im thinking they will be nice I know the same company offers ones that close or you can put a rubber cap over the naca ones
06-18-2018, 01:33 PM
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