jeepwm69 7,611 Posted March 18 On 3/15/2024 at 8:22 PM, Melatv said: Hi -- the wires with just the insulation covering just chew off -- use Permatex Liquid Electrical Tape -- I don't like using those heat shrink tubes with solder in them -- because the wires have to be perfectly clean -- solder the connections tape them good -or use crimped connectors and liquid tape the ends. So, this might be a stupid question, but I’m starting to think I have burned/melted wires in the harness somewhere. Is that what you electrical experts are leaning towards? I’m eyeing this https://www.ebay.com/itm/256307769169 Since the CKP test looked ok, safe to say the problem should be in the harness/ECU? 1 Share this post Link to post Share on other sites
retro 4,048 Posted March 18 2 hours ago, jeepwm69 said: Since the CKP test looked ok, safe to say the problem should be in the harness/ECU? That is my thinking too. In my mind I had narrowed it down to either the JC 2 junction in the harness and/or the ECM. I was trying to stay away from the ECM... don't feel comfortable making those calls on the Internet. That is a good price for a used harness it's and loaded with parts. What do you think Mel? Share this post Link to post Share on other sites
Melatv 792 Posted March 18 HI @retro & @jeepwm69 I would un tape everything around that solder connector -- make everything right and try it. If still a problem then ECM or other things are the problem. The harness is a good deal if the person is willing to buy it first without cost to you. 1 1 Share this post Link to post Share on other sites
jeepwm69 7,611 Posted March 22 Made an offer on that ebay wiring harness and ECU, which not only was rejected, but then the listing was pulled altogether as "no longer available"..... The 2012 and 2013 were oddball years, so finding another wiring harness isn't going to be fun. I'll keep poking around on this one and see if I can get anywhere. Share this post Link to post Share on other sites
jeepwm69 7,611 Posted March 26 Was out of town for a few days visiting the in-laws. Going to try to dig back into this thing this week. @Melatv and @retro, IF one of these connections I redid is the problem, wouldn't I be able to check that by checking for resistance between the ECU plug and the wire a bit on the other side of the repair? The rats gnawed the wires pretty close to the ECU plugs, and it didn't give me a lot of room to work. So, at this point, I can either buy a new harness, fix this one, or buy a new ECU. I hate throwing money at machines. If I can verify that my splices are ok with a resistance test, I'd lean towards a fried ECU. If my splices are bad, wouldn't they show resistance? Share this post Link to post Share on other sites
jeepwm69 7,611 Posted April 1 Had a few minutes yesterday while waiting on the turkey to fry (I set up my fryer kinda close to the pile of broken down Hondas so I could tinker while monitoring the oil temp). I unhooked the ECU plugs and checked for continuity on the wires that I spliced together. I did this by inserting a pin into the connector, and then shaving a bit of insulation off the wire a good 2-3 inches on the other side of the splice, and then checked for continuity. Both of my splices gave me a tone and showed 0.00 resistance, so that SHOULD mean my splices are good and flowing properly, correct? Can I take these apart? I also have continuity between fuse block and the bottom of this little box, with no resistance, so hypothetically, were I to take some of the wires coming out of this box, and do a similar continuity/resistance test would that show an internal problem within this box? @Melatv @retro Share this post Link to post Share on other sites
retro 4,048 Posted April 3 On 3/26/2024 at 12:02 PM, jeepwm69 said: So, at this point, I can either buy a new harness, fix this one, or buy a new ECU. I hate throwing money at machines. If I can verify that my splices are ok with a resistance test, I'd lean towards a fried ECU. If my splices are bad, wouldn't they show resistance? Well, continuity and resistance tests are meaningful only when a wire repair bonds every copper strand inside the wire together and you're 100% sure of that. So for instance, if a broken wire is soldered back together but several of the strands did not get bonded, but two or three strands did get bonded, then that wire repair would test as a good one, but would not necessarily conduct all of the current that the wire (repair) is required to handle during operation under it's normal full current load. In that case the wire would only measure a higher resistance than normal while under load. That is the reason why @Melatv suggested that you redo the repair that has the all-in-one solder/heat shrink gimmick on it. You can never be sure that the wire strands got hot enough for solder to flow into them to create a bond when using those sort of shortcut gizmos.... the wire conducts heat away quickly along it's length and commonly leaves you with a pretty pool of melted solder --- but a cold solder joint. A good temperature controlled soldering station is a must-have for harness repairs. Weller is one of the best affordable brands... 1 Share this post Link to post Share on other sites
retro 4,048 Posted April 3 On 4/1/2024 at 12:04 PM, jeepwm69 said: Both of my splices gave me a tone and showed 0.00 resistance, so that SHOULD mean my splices are good and flowing properly, correct? As explained above.... maybe, maybe not. On 4/1/2024 at 12:04 PM, jeepwm69 said: Can I take these apart? I also have continuity between fuse block and the bottom of this little box, with no resistance, so hypothetically, were I to take some of the wires coming out of this box, and do a similar continuity/resistance test would that show an internal problem within this box? Again maybe, but maybe not. That harness junction could have an overheated pair of wires inside it where they connect together that measures good, but does not pass enough current while under load. Similar to a fuse that overheats the terminals where the fuse plugs in inside a fuse box.... you've seen those failures before.... so you can't rule that possibility out until you get your eyes on the joints in question. I have never tried to open one of those harness junctions so I'm ready to learn what it looks like inside of them, if you are? All along I have suspected that the ECM is at fault but I've been staying away from that talk because I have no idea how it could be tested. 1 Share this post Link to post Share on other sites
retro 4,048 Posted April 3 This is off-topic but I have an idea that could help us all. Honda stopped including resistance tests in service manuals long ago, so I am thinking about measuring resistance on Ignition coils that I have laying around that are known to be good coils. We could each make a list of resistance tests of coil part numbers that we have on hand and then publish them in a sticky maybe...? @Mach 1 needs those resistance tests right now. 1 Share this post Link to post Share on other sites
jeepwm69 7,611 Posted April 3 I'm still kinda keeping an eye out for a used harness or ECU. The one I had on ebay had both, but he pulled the listing, removed the ECU, and jacked the price up $100 on just the harness. Buying both new will be about $500-600. So I'll try redoing those connections first, and then will tinker with it when I have time, while keeping an eye out for a harness or ECU. 1 Share this post Link to post Share on other sites
retro 4,048 Posted April 3 I am back home now so I'll read back through this thread later tonight after my work day is done. My intuition is firing off so I might have missed something. Share this post Link to post Share on other sites
jeepwm69 7,611 Posted April 3 A used harness and ECU hit ebay in the last day or two, different seller. $149 for the ECU and $199 for the harness. While tossing both at the machine will likely fix it, were it mine I think I'd replace one, and then if that didn't fix it, get the other. I'd lean towards the harness replacement first, since the existing harness is already chewed up and spliced on in several places. If I buy the ECU first, and it's the harness, then I'd have an extra ECU that wouldn't be needed. If I buy the harness and still need the ECU, at least the harness would no longer be all chewed up. But I really hate to throw money, especially someone else's money, at a problem. And on the other hand...... This voltage drop......let's say I think it needs a harness...wouldn't using MelATV's little "jumper wire from battery + to the red/black wire on the coil" bypass any burnt/broken wires in the harness by directly supplying 12V to the coil and back feeding 12V to the rest of that circuit IF that were the issue? You know I don't like wiring. I tend to think of it like plumbing, with flow of electricity instead of flowing of liquid, but I know it's not that simple. But looks like if I had a restriction somewhere from overheated/ burnt wiring that would cause a voltage drop, that a jumper wire would "bypass" that restriction. Which would point to the ECU...... PSN has an 18% off sale going through Sunday, and they have an ECU, but not a wiring harness. Of course, the good thing there being they stand behind what they sell. Share this post Link to post Share on other sites
retro 4,048 Posted April 4 11 hours ago, jeepwm69 said: This voltage drop......let's say I think it needs a harness...wouldn't using MelATV's little "jumper wire from battery + to the red/black wire on the coil" bypass any burnt/broken wires in the harness by directly supplying 12V to the coil and back feeding 12V to the rest of that circuit IF that were the issue? Yeah, jumpering battery voltage to the coil would bypass a high resistance joint in the harness. It would do nothing for a shorted wire though. As you said a harness and an ECU should fix it. Your logic is solid too, swap the harness then the ECU.... it's big bucks and a lot of tedious work but it would be fixed right. Share this post Link to post Share on other sites
Mach 1 21 Posted April 10 On 4/3/2024 at 1:20 PM, retro said: This is off-topic but I have an idea that could help us all. Honda stopped including resistance tests in service manuals long ago, so I am thinking about measuring resistance on Ignition coils that I have laying around that are known to be good coils. We could each make a list of resistance tests of coil part numbers that we have on hand and then publish them in a sticky maybe...? @Mach 1 needs those resistance tests right now. I posted mine this morning on a new oem coil 1 Share this post Link to post Share on other sites
jeepwm69 7,611 Posted April 14 New wiring harness installed this morning. Got everything plugged in, no change. Same exact voltage drop at the ignition fuse once I put the fuse in, but reads full battery voltage on the battery side of that fuse’s spot with the fuse removed. The only thing I can think now is the ECU is bad. I hate that this poor woman is going to be out $400+ for a coil, harness, and ECU, but at least now she’ll have a non-rat chewed ECU. @AKATV @Melatv @retro have any of you opened up one of these newer ECU’s? I’m just curious if we get 20 years down the road if these things will all end up as junk due to a lack of availability, especially on oddball models like the 12-13 Foreman Share this post Link to post Share on other sites
shadetree 5,869 Posted April 14 16 minutes ago, jeepwm69 said: New wiring harness installed this morning. Got everything plugged in, no change. Same exact voltage drop at the ignition fuse once I put the fuse in, but reads full battery voltage on the battery side of that fuse’s spot with the fuse removed. The only thing I can think now is the ECU is bad. I hate that this poor woman is going to be out $400+ for a coil, harness, and ECU, but at least now she’ll have a non-rat chewed ECU. @AKATV @Melatv @retro have any of you opened up one of these newer ECU’s? I’m just curious if we get 20 years down the road if these things will all end up as junk due to a lack of availability, especially on oddball models like the 12-13 Foreman man..you must really love these 500's to go through this much trouble !!..lol. i'm sooo glad i don't work on those 500's anymore...spec the stupid es models !..lol. Share this post Link to post Share on other sites
retro 4,048 Posted April 14 4 hours ago, jeepwm69 said: have any of you opened up one of these newer ECU’s? I’m just curious if we get 20 years down the road if these things will all end up as junk due to a lack of availability, especially on oddball models like the 12-13 Foreman I haven't opened one yet. I haven't even worked on any of the 420s or 500s that had a bad ECM yet. I'm just guessing but, those ECMs are probably potted in resin (like the old CDIs, Fan Control and Shift ECM modules are) which could mean they could be a bugger for desperados to repair. Share this post Link to post Share on other sites
jeepwm69 7,611 Posted April 14 14 hours ago, retro said: I haven't opened one yet. I haven't even worked on any of the 420s or 500s that had a bad ECM yet. I'm just guessing but, those ECMs are probably potted in resin (like the old CDIs, Fan Control and Shift ECM modules are) which could mean they could be a bugger for desperados to repair. they are. Certainly wouldn’t be easy to get into one without destroying it, but necessity is the mother….. Share this post Link to post Share on other sites
shadetree 5,869 Posted April 14 34 minutes ago, jeepwm69 said: they are. Certainly wouldn’t be easy to get into one without destroying it, but necessity is the mother….. trust me, you will not get into it, without destroying it..lol. they are filled with an epoxy resin, and this resin is not very kind...lol. Share this post Link to post Share on other sites
retro 4,048 Posted April 14 Well, epoxy melts at 450-550 degrees F, depending on the resin type so whenever those desperado days come around I'll be firing my WWII (mfg 1945) Tappan Deluxe! Share this post Link to post Share on other sites
jeepwm69 7,611 Posted April 19 It was the ECU. Got a used one from PSN today and it fired right up. Gotta get everything put back together and get it out of the yard. 2 Share this post Link to post Share on other sites
shadetree 5,869 Posted April 19 15 minutes ago, jeepwm69 said: It was the ECU. Got a used one from PSN today and it fired right up. Gotta get everything put back together and get it out of the yard. of course..the most high dollar part there is..lol ( unless you buy used anyway )..lol. Share this post Link to post Share on other sites
jeepwm69 7,611 Posted April 20 2 hours ago, shadetree said: of course..the most high dollar part there is..lol ( unless you buy used anyway )..lol. was $200 for a used one! Share this post Link to post Share on other sites
shadetree 5,869 Posted April 20 1 hour ago, jeepwm69 said: was $200 for a used one! yikes !. Share this post Link to post Share on other sites
Mach 1 21 Posted April 20 13 hours ago, jeepwm69 said: It was the ECU. Got a used one from PSN today and it fired right up. Gotta get everything put back together and get it out of the yard. So glad you got it going, great dedication in tracking it down, congrats jeep!!! Share this post Link to post Share on other sites
