MS3+MS3x Lost Fan Control
 

To start things off I have my fan output wired to INJG as in Westfields build guide. And it was working. Randomly it stopped working and the fan has been always on ever since. As soon as the key is on the fan is on.

List of things I have checked.

-Fan Relay Clicks when unplugged and plugged.
-Fan does not turn on when ECU is not connected.
-Thermoswitch disconnected

Attached is my msq. I'm assuming something on the board is fried, or I have a setting wrong. Any input is appreciated.

ADJ

Injector driver is dead.

What would have caused this?

Once again my problem stems from my failures, not the failures of the components.

Somehow I missed this when I was putting it together. Fan output shorted straight to ground...

https://www.miataturbo.net/attachmen...ine=1412106593

These drivers are known to randomly fail.

Check my reply above.

Looks good lol.

If an injector driver fails on the expander board is the only solution to buy a new board? I have already replaced so many items on my megasquirt that I am afraid of this happening to me. If so, I will have replaced nearly everything on my MS3 at least once...

They are under warranty for 1 year. If not under warranty (and if you are unable to handle the re-work/soldering yourself), the easiest solution is to buy a new card.

The VNDs fail pretty rarely actually. The only exception is there seems to have been a small bad batch of them about 4+ years ago.

Are they surface mount or through hole?

SMD.

That's exactly why I never opted to build MS3 harnesses like Frank's writeup. As much as I like the solution, I hate it.

The driver is $1.65 at digikey or mouser. it's probably the easiest SMD component to replace; or just move the output to any spares you might have.

Surface, but it's easy to work with as it's a large component with large pins.

It seems a lot better in concept than it does in practice. It limits your mounting possibilities, and really crowds the case. Oh well it was a good experience. The next one I build will use a DB-37 for sure.

I would even rather drill a hole through the case and run the wires out the db37 and then back into the case to the connector before I desoldered the expander board like that.