Wazz72 Posted February 2, 2005 Share Posted February 2, 2005 Can anyone help me, Im having problems wiring in a sat nav unit to my supra. Its a 93 J spec Supra, and im trying to find a wire under the dash that goes to the alternator. Aparently my Sat Nav unit needs a signal from this, to tell it that the car is moving, and not stationary. Without it conected my sat nav keeps shutting off, to save the battery, and cant tell where it is. Any Help would be apreciated. Thanks Link to comment Share on other sites More sharing options...
JustGav Posted February 2, 2005 Share Posted February 2, 2005 I wouldn't have thought you connect it to the alternator..... Are you sure it doesn't just need an lead off the ignition? Gav Link to comment Share on other sites More sharing options...
Wazz72 Posted February 2, 2005 Author Share Posted February 2, 2005 Yup it definatley says connect to the alternator charge, heres a scan of the wiring diagrams. Link to comment Share on other sites More sharing options...
SimonB Posted February 2, 2005 Share Posted February 2, 2005 It means the RPM wire. You can find it at the ECU, or from the back of the dials. Here's the ECU wire:- http://www.mohdparts.com/emanage/install/2jz-gte_install/ECU-MAF.JPG Can't remember which wire it is on the back of the dials, but you should be able to find it pretty easily if you take the dials out and have a look at the tracks on the back. Link to comment Share on other sites More sharing options...
JustGav Posted February 2, 2005 Share Posted February 2, 2005 Just looked at the diagram and it needs both by the looks of it... one to go to the alternator and one to go the tacho... Bizarre.... you would have thought it would go in like a radio, and if the gps can't realize it is moving or not, then I'd worried..... Gav Link to comment Share on other sites More sharing options...
Wazz72 Posted February 2, 2005 Author Share Posted February 2, 2005 Yup It Needs one from the RPM to show the on screen MPH, and directions when out of range of GPS signal. But I still dont know what colour, and where the alternator wire is? Help! Link to comment Share on other sites More sharing options...
SimonB Posted February 2, 2005 Share Posted February 2, 2005 Yup It Needs one from the RPM to show the on screen MPH, and directions when out of range of GPS signal. But I still dont know what colour, and where the alternator wire is? Help! The one to show on screen MPH is a speed signal, so that one will come from the speedo (or output from your speed convertor). The alternator one is the RPM, which you will find on the ECU shown on that diagram, or from the back of the dials too. The RPM signal IS the alternator signal is what I'm saying, you get one pulse per revolution of the engine. Oh, BTW the colours on that diagram are not the colours of the ECU wires, so don't pay any attention to them. I think the RPM wire is black/white IIRC, but I could be wrong there. Link to comment Share on other sites More sharing options...
JustGav Posted February 2, 2005 Share Posted February 2, 2005 Chap... having the RPM's won't be used for speed.... After all doing 60 in 2nd, and doing 60 in4th will give different RPMS at the same speed.... Sounds very odd... the alternator wire still confuddles me no end... Link to comment Share on other sites More sharing options...
JustGav Posted February 2, 2005 Share Posted February 2, 2005 The RPM signal won't be the alternator signal as that has no bearing what so ever on engine speed... by putting on smaller pulleys does not mean my RPMs go up... Link to comment Share on other sites More sharing options...
SimonB Posted February 2, 2005 Share Posted February 2, 2005 Hmmm, maybe it just wants a wire that indicates whether the engine is running or not, the alternator would do that I suppose. I was thinking of what they call the "Ignitor" on the ECU wiring diagram, which is just an ignition signal that you get a pulse on per cylinder (i.e. 6 per RPM), so that was bolox that I posted! Link to comment Share on other sites More sharing options...
Wazz72 Posted February 2, 2005 Author Share Posted February 2, 2005 I think it was speed pulse not rpm for speed. So what wire should I use for the one that says alternator? Link to comment Share on other sites More sharing options...
JustGav Posted February 2, 2005 Share Posted February 2, 2005 Something I just thought of... it isn't perhaps the signal to say the alternator is charging rather than draining the battery? in which case I have no idea which pin Link to comment Share on other sites More sharing options...
Wazz72 Posted February 4, 2005 Author Share Posted February 4, 2005 Still not had any luck? Anyone had any ideas? Link to comment Share on other sites More sharing options...
Markie Posted February 5, 2005 Share Posted February 5, 2005 I would say that you need the speed wire connected to see if the car is moving which you have said, would you not be able to get a wire from the alternator running somewhere.. I dont think you will have a wire to the alternator running near the bulkhead. you dont have a voltage meter on yours do you? Does it run straight off alternator or something? Or needs a current to continually charge something? This is all guess work by the way :upside: Link to comment Share on other sites More sharing options...
RobSheffield Posted June 25, 2005 Share Posted June 25, 2005 did you find a result to this mate? im doing this on my car tomorro - need to find the speed pulse wire Link to comment Share on other sites More sharing options...
jackso11 Posted November 29, 2005 Share Posted November 29, 2005 Any news on this? I spoke to kenwood and they seem to think it is a blue & red wire from pin 2 on the ecu. Correct? Link to comment Share on other sites More sharing options...
SupraHuman Posted November 29, 2005 Share Posted November 29, 2005 The speed sensor is the no.2 wire on e10 on the back of your ecu. Link to comment Share on other sites More sharing options...
jackso11 Posted December 11, 2005 Share Posted December 11, 2005 would I need to take the feed from here? or should I take it from the back of my Thor speedo converter? Link to comment Share on other sites More sharing options...
Matt Harwood Posted December 11, 2005 Share Posted December 11, 2005 Take it from the speedo converter wire that goes to the speedo, not the ECU. Otherwise you'll have a 'capped' signal from about 110mph onwards.... Not that you drive that fast of course!!! Link to comment Share on other sites More sharing options...
Matt Harwood Posted December 11, 2005 Share Posted December 11, 2005 Just to add, I can't really see why a navigation system would need an alternator signal or an RPM signal. Any sensible ideas/reasons? Link to comment Share on other sites More sharing options...
jackso11 Posted December 12, 2005 Share Posted December 12, 2005 cheers for that Matt. So from memory, was that the blue wire? won;t get a chance to do it until the weekend now. no idea why anyone would need a RPM or alternator signal though. or maybe they tell the unit the car is running to allow cut off to save power? I would have thought they could just read voltage or park prake for that though. Link to comment Share on other sites More sharing options...
jackso11 Posted December 12, 2005 Share Posted December 12, 2005 Also...where is the best place to put the GPS antenna? Link to comment Share on other sites More sharing options...
jackso11 Posted December 20, 2005 Share Posted December 20, 2005 Link to comment Share on other sites More sharing options...
Recommended Posts
Please sign in to comment
You will be able to leave a comment after signing in
Sign In Now