greddy32 Posted April 25 Author Report Share Posted April 25 What should voltage be on 45 whioe cranking? And am I testing it correctly? Quote Link to comment Share on other sites More sharing options...
Adamw Posted April 25 Report Share Posted April 25 Pin 45 is from the ignition switch, it should show close to battery voltage whenever the ignition switch is on. If it drops below about 7.5V the ECCS relay will drop out. Note on a BNR32 this wire also supplies the fuel pump, oxy probes, idle valve, AC relay, boost valve & EGT sensor, so it is a fairly overloaded circuit, not uncommon to see low voltage on it as the ignition switch wears and all the connections along the way get more resistance with age. 21 hours ago, greddy32 said: It doesn't show any voltage on 45 while cranking or ever for that matter. 1 lead on 49 the other on 45 while testing Should be measuring between ground and 45. Quote Link to comment Share on other sites More sharing options...
greddy32 Posted April 25 Author Report Share Posted April 25 So I'll retest test with 45 and ground and let you know what it says.. if it's low whats the solution? A new ignition barrel? Also would running all ecu grounds directly to a batt(-) stud help at all? Quote Link to comment Share on other sites More sharing options...
Adamw Posted April 26 Report Share Posted April 26 Confirm if that is the issue first. Will need to do a bit more digging to suggest the best solution. For example if the fuel pump is still supplied by the ignition switch it would probably be best to change the fuel pump supply which will take a lot of load off that circuit - But that may already done for all I know. So at this stage Im still trying to confirm if your issue is on the triggering side of the ECCS relay or on the high power side or something like a ground issue. 1 hour ago, greddy32 said: Also would running all ecu grounds directly to a batt(-) stud help at all? I dont remember what the grounding scheme is like on the GTR but generally older Nissans main ground point is on the engine as some devices including the CAS and ignitor ground through their body/mounting. Changing to batt -ve wouldnt be recommended if this is the case. Quote Link to comment Share on other sites More sharing options...
greddy32 Posted April 26 Author Report Share Posted April 26 Okay my son is asleep for the night so I won't be able to test any cranking until tomorrow. To your example, my fuel pump is getting 12v triggered from the trunk, it's reloomed but I'm assuming it's the circuit you're referring to. Where would I grab 12v from thats not on the same ignition switch? Quote Link to comment Share on other sites More sharing options...
greddy32 Posted April 26 Author Report Share Posted April 26 Off topic but which was is the correct way to wire a radiator fan? 30 batt 87 fan 85 ecu 86 switched 12v Or 30 batt 87 fan 85 switched 12v 86 ecu Quote Link to comment Share on other sites More sharing options...
greddy32 Posted April 26 Author Report Share Posted April 26 45 drops from 12.5 to 7.73 while cranking Quote Link to comment Share on other sites More sharing options...
Adamw Posted April 26 Report Share Posted April 26 That sounds a bit borderline considering a multimeter has quite a low update rate. Just reading back at some of your earlier posts in this thread, you mentioned you had done a test by grounding pin 16 with a bit of welding wire or similar - did the ecu stay connected when cranking when you done that? Quote Link to comment Share on other sites More sharing options...
greddy32 Posted April 27 Author Report Share Posted April 27 It did stay connected but only 1 time for some reason. I've tried a couple times since and the ecu always disconnects Quote Link to comment Share on other sites More sharing options...
Adamw Posted April 27 Report Share Posted April 27 Hmm, thats odd. Can you try setting up ecu logging like below, with just engine speed and batt voltage logged at 100Hz, no control conditions so it just logs all the time the ecu is on. Then do a couple of cranks and download the log. That will at least confirm it is shutting off rather than just a USB issue and if it is shutting off it may capture what was happening to battery voltage just before that point. Quote Link to comment Share on other sites More sharing options...
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