I'm an electrical noob, so please be gentle I've got a bunch of 90s-era interceptor units that I want to play around with, and I'm wondering what issues (if any) I'll run into if I follow the instructions and splice them all (three in total) into the ECU's power wire. Would I be increasing the chance of blowing the ECU fuse or damaging the ECU itself? If it makes any difference, the units are an Apexi S-ITC, Apexi SAFCII and an Apexi Multichecker (already installed). Thanks lads.
If all your power wiring is in good order with no pesky resistance/voltage droppping then theres usually no real reason against adding additional items onto a given circuit. Most of these kind of accessories draw pretty low current on the +ive side so you should be ok. Check their combined current draw and allow for this fuse wise. My personal preference is to provide a dedicated fused circuit for such additions tho. Just me. E
Cheers Tas, thanks for the response. I quizzed a sparky mate (non-auto) and he said much the same thing, so if I can find a conveniently placed power wire in the footwell area that's switched to ACC I'll give them their own power source.
Only thing to add to this is if you're using another source for power, make sure there is nothing on that source that has high power draw, ie fans etc, as when these turn on they can affect the voltages going to your electronics and can affect readings. This is why most of these electronics recommend you run off the same power and earth as the ECU.
take the power from your headunit. then if some thing does go wrong you can still drive home. also if you blow it. it is just a fuse in either the engine bay or the kick panel. ecu and headunit only about half a meter from each other.
Check whether these ECU gadgets run 5 or 12volts. Electronics is usually 5volts but accessories are usually 12volts (unless they are USB powered which makes them 5 volts) Warning: if anyone is planning on hardwiring their a cam DVR into the loom, multi test that round power plug, it might be 5, 6 or 9 volts) If you need a 5 or 12 volt power source you could use ECU power as a signal source for a relay (but put a diode on that to be safe)
Not a bad idea. There are plenty of modular fuse/relay holders out there these days -it wouldn't be hard to make up a dedicated box to run your three accessories off their own circuits. Much neater and probably a little safer and certainly more consistent voltage than splicing into various points of the factory loom.
These gizmos are engine management related so make sure you power them off the "Run" position on the key and not the "Acc". You dont want these things running when the engine is off. E
