New Fuse Box.

Next the Main Power (multiple 60A) fuse box was linked into the harness and a large power supply got hooked up to that.

The final part of the puzzle was always going to be the speed input. The clocks and the ECU need a speed signal (along with the plan for a cruse control later in the cars life). As ABS was not going to be used, the original Saab speed signals were no longer available. So what to do? Hit the Internet!

Loads of cheap signal conditioners were available that could take the input from a wheel sensor, but not many gave much scope for configuration or multiple outputs. I finally came across a unit Called an SPU1 from Sails Marketing Ltd. This unit allows for 2 voltage outputs & 2 clean contact outputs plus a choice of 12V or 5V outputs and a range of filters and scaling options Ideal! I'll take one sir.

SPU1 Speed pulse converter.

Hooking the wheel sensor up to the SPU1 and playing with Drill guns and bolt heads soon had the speedometer working. Odd but it was very happy to run at the 5V output setting and I wondered if the ECU would be equally pleased. Only time would tell.


After checking all the switch gear and repairing all the leaking smoke. actually there was only one short on the light switch, the on board computers (ECU and ICE) and displays (SID and Clocks) could be fully tested using OBD II fault code and CAN bus interfaces and software. EasySync had alreday provided me with a the CAN bus Interface for another project, while ScanTool with ELM327 provided the OBD II interface. Using the ScanTool and ProScan software for the OBD II plus T5Suit and CAR PC software for CAN Bus. Hopefully this will not put my laptop or grey cells to to much work checking out all the possible functions while the looms are on the test rig.

The hardware interfaces are all USB with serial port emulation. The ODB II until comes with all the require cables plugs and sockets, while the CAN bus interface uses a USB connection to an interface box that requires a 15 way D type connector to Saab CAN bus square connector cable manufacture (and just when I thought the wire bending was over).

But then comes the EasySync woes! Yes Easysync CAN-USB2-F-7001 will hook up to the Saab Trionic 5 and work, if you write your own software. At this point in time T5Suite will not talk to the Easysync device. So after some happy hours with Delphi I finally get to iron out a few more wiring bugs, mainly earth problems and nothing too serious. Then it's time to purchase a Lawicel CANUSB device. Now this should have been simple................

Laptop, Brown box is EasySync, Blue is Lawicel & Silver is ELM327.

But the Lawicel install instructions are misleading, to say the least. When the device first installs it kindly forgets to set up a Virtual Communication Port (VCP). This means the Windows makes all the right noises when you plug / unplug the CANUSB but it never appears available for use. So we search and we look and we scratch head.

Finally we find the damn thing hiding under

Control Panel -> Device Manager -> USB Devices -> Lawicel USB.

When you open the Properties for this device and then Click the Advanced tab you will see a check box that says "Load VCP". Check this and the suddenly windows will find a new device and install a COM port for you to use. Actually windows says you can use the Advanced tab to change the way the device "usually operates". So if you don't want the device to do more than make a sound when plugged in I would suggest you change the way the device operates!

Now all is well and I can chat happily to my ECU.

The Elm327 device was a dream to use, no problem with it at all, well apart from the fact that I had accidentally cut off pin 7 from the cars Com port plug. I wondered what that grey/black wire was doing under the passenger seat in the old 900. Now I know, it was hooked up to the alarm unit and via that to the ECU TECH II and OBD II communications. Ho hum never mind.

Reading fault codes, clearing Check Engine Lights (CEL) and downloading all the tuning parameters from the ECU is now a breeze and Tuning (once the beast runs) will now be possible.

Click here to see Wiring The Beast 2.

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Wiring - The Beast Bites

The “stop smoke escaping” policy involved a bit of thought, several large pieces of chipboard and a shed load of P-Clips. Laying the internal wiring out on chipboard, as if it were a dash, and then laying out the engine wiring on a separate board allowed the entire internal and engine looms to be viewed and worked on. High current wiring, lights (including high power relays), battery and main fuses and fuse box could then be wired through bulk head plugs and sockets. Finally a heavy duty power supply could then be hooked up to run the entire harness.

T5 Wiring Test Rig.

The plan was a good one and the initial wiring looms panned out well. As with all prototype wiring looms though, things needed work. Using Mate Lock plugs and sockets and original Saab plugs and sockets, where possible, to pass through the fire wall meant only a new fuse box was needed. This was all designed using the original fuse moulding but cut and shaped to fit into a large die case IP65 sealed box. With the addition of a few 12V LEDs to indicate HI, LO, FOG and FAN functions a terminal strip to allow modified wiring and external light wiring, things were looking good.