help with fan control


I am having trouble getting my fan control circuit to work. I have followed the diagram in the extra manual that uses 1k and 2n2222 . I have the fan on relay like the diagram. But I cant seem to get the transistor to do anything. On the js0 I can get it to switch for 0 to 0.8v. So I think I might have a problem there. What should be coming from the ecu(js0) I don't think the 0.8v is enough to switch the transistor.

I am using ms2 on v 3.0 board. Any help would be great thank you.

 

It sounds like your CPU is trying to switch at JSO but you have the transistor wired wrong. This is why the JS0 only gets to 0.8V. If you can refer me to the wiring diagram you used for the 2n2222, then maybe I can help sort it out. Perhaps you were looking at the connections from the top end of the 2n2222 instead of from below? You should have the 1k resistor connected between JS0 and the base (center pin) of the 2n2222. The emitter (the arrow) goes to ground. Your fan relay should be connected to the collector of the 2n2222.

 

I used the diagram in Arroncake wright up. I think I have a issues in the board. I test another board and it has 5v at the jso. My board only get 0.8v so there is a problem somewhere. I know need to troubleshoot why the I am not getting the 5v from the processor. I am 100% sure I have the circuit built right just a problem in the board I need to find.

http://www.megamanual.com/ms2/SpareCircuit.gif

 

I checked my notes on my build. Funny thing is I tried using JS0 and found mine to be faulty too. I just moved the fan to JS2 and made the appropriate changes in the setup. In the MSII, JS0 thru JS3 are the stepper motor control outputs normally used for IAC on other installations. They can drive a relay coil directly without the need for the 2n2222. See my post and Ken's response: https://www.rx7club.com/megasquirt-forum-153/new-build-ms2-extra-2-1-0-a-817354/

 

I found that too but I still have the problem of not enough voltage at the js0-3 I tried them all. It must be the ms2 card . I use my ms1 and it works. So I quess it might be time to upgrade to ms3 lol.