Not sure if this is the right place for this, but i am looking for some help making an aldl cable. I am having a little trouble understanding the wiring diagram in the attached picture. From what ive read on other posts is that i dont need the r3 resistor or the r4 resistor(92 RS), but i still wire in those two circuits right? just without the resistors? Also, I dont understand what is going on in that circle above "Q1"? Would somebody who has made this cable before be able to quickly modify the picture in MS paint to clarify the wiring? Sorry if this is a dumb question but id hate to spend $60 when i can just make my own.

Thanks!

Link:
http://winaldl.joby.se/aldlcable.htm

 

If you dont need the r3 and r4 leave them out and no wiring for them either.

Q1= the circle is the symbol for a transisor, a transistor have 3-legs (base,emittor,collector)


/N.

 

Oh ok so then i guess ill go and get a transistor, so A and B on the Connector don't need to be wired?

Thanks GTA

 

I would suggest just buying one...

I've made a few now, and the need for external power (not shown in that diagram), can be annoying. They were also not very reliable, especially if your laptop doesn't have a bonefide serial port, most serial to USB converters seem to have issues with the odd baud rate of the ALDL dataline. The diagram assumes that the serial port will be able to "phantom power" the circuit, some laptops will be able to, while a lot of laptops won't, and I haven't seen any serial to USB converter that will power the circuit.

The R3 is for older MAF systems that used the '165 ECM, no other ECM that I'm aware of needs that resistor. A still needs to be connected, because that is a ground reference.

I use a MAX232 based home made ALDL cable on my desktop (bonefied serial port) for use with my test bench, but have trouble getting it to work with my laptop, due to the need for a converter.

The $80 I spent on the Moates' ALDU1 (Xtreme ALDL), was the best purchase I have made for tuning/logging. It's USB, and dead on reliable.