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Microsquirt ALED channel crapping out

kyote

Living The Dream
Joined
Apr 27, 2003
Location
La Porte TX
On the Mail Jeep, ALED was/is used to control EFAN.
This channel seems to have given up the ghost, was working intermittently and now not at all.
Is this a board level component than can be replaced?
Originally was driving a Volvo EFAN relay, now driving an 80A cube relay.
Please help me free the old man from being tethered to a switch based EFAN setup :)
 
ALED (aka D16) is driven by a generic 3904 NPN transistor (Q8), $0.05 plus shipping. How do you have the relay wired? LED pin to one side of the relay coil, and the other side of the relay coil to switched +12V?

Before taking anything apart, I'd try the I/O Test Modes menu in Tuner Studio and see if turning on and off LED D16 lights up the ALED and/or runs the fan. Depending on where the fan relay is getting power, you might need to enable the fuel pump relay first.

edit: nevermind, you're talking MicroSquirt, not MegaSquirt. MicroSquirt drives the ALED pin with a 3NV04D mosfet driver - 8pin surface mount chip. It might be replaceable by someone with surface mount rework equipment. I'd check the wiring first.
 
ALED (aka D16) is driven by a generic 3904 NPN transistor (Q8), $0.05 plus shipping. How do you have the relay wired? LED pin to one side of the relay coil, and the other side of the relay coil to switched +12V?

Before taking anything apart, I'd try the I/O Test Modes menu in Tuner Studio and see if turning on and off LED D16 lights up the ALED and/or runs the fan. Depending on where the fan relay is getting power, you might need to enable the fuel pump relay first.

edit: nevermind, you're talking MicroSquirt, not MegaSquirt. MicroSquirt drives the ALED pin with a 3NV04D mosfet driver - 8pin surface mount chip. It might be replaceable by someone with surface mount rework equipment. I'd check the wiring first.

Wiring good, if I ground the wire headed to microsquirt fan comes on.
No way I can do surface mount, hands too shaky, but surely someone can :)
 
Yeah, my nerves and eyesight make SMT work pretty difficult these days. A cell phone repair shop might be able to swap the part if you get a replacement from digikey.com. I'll see if I have a picture somewhere of the board/part.

Do you have any other spare MicroSquirt outputs that you could use instead of ALED?
 
Yeah, my nerves and eyesight make SMT work pretty difficult these days. A cell phone repair shop might be able to swap the part if you get a replacement from digikey.com. I'll see if I have a picture somewhere of the board/part.

Do you have any other spare MicroSquirt outputs that you could use instead of ALED?

The highlighted are in use (obviously ALED no working).
Can I use a SPAREADC channel to drive the fan relay?
 

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Sorry, it looks like only the 4 pins in yellow can be used for coolant temperature based fan control using "programmable output" mode. Are you running a DSM CAS with full sequential spark?
 
Running LH 2.4 style CPS and LS Coil Near Plug setup.
That is what I thought, wonder if anyone on TB got the Surface Mount Touch?
 
I'm assuming you're using one wire (spark a,b,c,d) per coil? If the coils are true "logic level" coils, you could double them up with two coils per spark wire and use wasted spark mode. This would free up the spark c,d wires for fan control and a spare.
 
SMD repair on low pin count chips isn't that bad. The biggest hassle is getting the old chip off unless you have a hot air rework station. Sparkfun or Adafruit have a tutorial on soldering in SMD chips using flux, a soldering iron and solder wick. Works quite well although it probably causes the professionals to gag. I found that it helps to use a dab of cyanoacrylate to keep the chip in place so that you don't move it around on the pads when re soldering with the iron or re flowing with the hot air rework device. Oh, and for those over 40 a an optivisor can help with seeing what you are doing.

If you don't have the patience then sending off to DIY is probably best.
 
SMD repair on low pin count chips isn't that bad. The biggest hassle is getting the old chip off unless you have a hot air rework station. Sparkfun or Adafruit have a tutorial on soldering in SMD chips using flux, a soldering iron and solder wick. Works quite well although it probably causes the professionals to gag. I found that it helps to use a dab of cyanoacrylate to keep the chip in place so that you don't move it around on the pads when re soldering with the iron or re flowing with the hot air rework device. Oh, and for those over 40 a an optivisor can help with seeing what you are doing.

If you don't have the patience then sending off to DIY is probably best.

I am confident that I can solder, but like I said my hands are too shaky for something that tiny and sensitive.

I will likely just send to DIY for repair, did not know that was an option.

Thanks for all the input dudes!
 
Back with an update.
Sent to Diyautotune to repair, no problem found.
Hmm...
Ran in a switch until today...

... Broken wire at the relay on the ECU switched side ;)

Working like a cham peen!
 
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