EdBwoy wrote: ↑Wed Apr 07, 2021 12:50 am
You said you replaced a lot of the fuses in the car, but I would like to clarify does that mean inside the cabin or car in general?
I ask because there are some fuses and fusible links in the engine bay that I would be interested in checking first. These are located in front of the battery, and while at it, you might as well visit the IPDM.
I have a high level guide, but apparently I have never gotten around to uploading the labels of each of those fuses.
major-fuses-relays-and-modules-and-thei ... l#p6780240
Once I have gotten the battery hooked back up at the start of this whole thing and saw the car was not starting and had the dead behavior of the pushbutton, the first step I took was to check fuses. I looked up a diagram with label of what each fuse in the cabin was for and checked the 3 fuses that had anything to do with the car starting up. I pulled the fuses out one at a time, visually inspected and then tested with a multimeter and got a nice 0 Ohm reading. When those 3 checked good, I started back at the beginning and checked every fuse starting with #1 inside the cabin one at a time with a visual check and multimeter. This included a double check on the 3 I had already done first, which was fuse 22, then fuse 21, then fuse 1.
With the cabin all checking out good, I moved to the engine bay. I did a check on every fuse in both fuse boxes located there. The "weird looking fuses" that are shaped funny I also checked visually and with a multimeter.
When every fuse in the car checked out good with a 0 Ohm reading, I started to get worried that I had fried something important and came to post here about my thoughts on it being either the BCM or i-key unit.
edit: I used this site to find a description of the fuses and their location:
https://fuse-box.info/infiniti/infiniti ... and-relays
I did not know specifically what the IPDM was so I looked it up just now and it appears this is it?
https://partsbeast.com/Infiniti/M35-Par ... Box/306888
If that is correct, I checked all the fuses in that unit. I did not know it was a specific controller, I just thought it was a board with fuses and routed power to the relays.
I looked on Amazon and found a pack of fuses for about $10 and a 5 pack of relays for around $5. So I bought all that because it is prudent to have some automotive fuses around anyway for issues that arise. Just for good measure, I replaced every standard fuse in the car. By that I mean every "mini low profile fuse" in both the cabin fuse box, the engine bay fuse box, and the other engine bay fuse box which is apparently the IPDM. The only fuses I did not replace are those special shaped ones in the long skinny fuse box.
I also replaced all the 4 pin relays in the IPDM just for good measure as I came across something in my searches that said one of them was related to the starter and another the ignition. I also read that the ECM relay ties into those systems but I do not know how correct that is. So with 3 of those relays being involved in the system having trouble I decided I should replace them just to check. I figured with the relays being 15 years old and a pack of replacements was only $5 I might as well replace all of them for good measure. I know at work we replace relays about once a year so they do wear out. granted the machines at my work run much more time than the ones in the car, but still after 15 years they have to be getting old.
VStar650CL wrote: ↑Wed Apr 07, 2021 4:25 am
True, depends what "checked" means. The only right way to check fuses is to probe both sides with a test light, if it lights on only one side then it's blown. If it lights on neither side then it has no power, which tells you something is wrong upstream like a fusible link or open wire. If the OP only pulled and checked the fuses visually, then the links will also need checking.
I did not check yet with a test light probe as I did not have one yet. I bought one to have on hand and it should be here today so I can check after work. I believe power to the fuses is fine though as all other electrical system in the car work fine.
I will post pictures of the 3 fuse boxes when I get off work so you can see all the fuses and which relays I replaced.
At this point I believe VStar650CL's opinion is correct, it is most likely the i-key unit.
edit again: I did not check the fusible link block on the positive side of the battery other than a visual inspection of them. I believed with it visually looking ok, not hearing any loud pop from one of those blowing, and with every other electrical system in the car being fine that those main links were ok.