MMiskoe Posted January 29, 2022 Report Share Posted January 29, 2022 Last year our Miata suffered a problem with an ECU ground that resulted in us doing about 20 laps at speed for the VIR 24 hour. It then took 2 days with an oscilloscope to find the problem. I'd like to avoid that so I'm looking hard at the wiring harness. Much of it is not needed anymore, don't care so much about AC or power windows etc. But for the parts that I do care about, I'm going to need some new connectors that will allow me to pin new wires into the connectors. If I can re-pin the existing plugs, I'll re-use them. I want to keep the OE fuse blocks for simplicity. But I'm going to need a ton of pins that are specific to the Mazda system. So who do folks go to and who does one identify what type of connector you have? Quote Link to comment Share on other sites More sharing options...
turbogrill Posted January 29, 2022 Report Share Posted January 29, 2022 Was there a loose ground to the ECU? Ballingermotorsports has connectors for Mazda. They sell connectors with pins that you crimp or pigtails. 1 Quote Link to comment Share on other sites More sharing options...
MMiskoe Posted January 29, 2022 Author Report Share Posted January 29, 2022 9 hours ago, turbogrill said: Was there a loose ground to the ECU? Ballingermotorsports has connectors for Mazda. They sell connectors with pins that you crimp or pigtails. The signal to the coil had a terrible profile, lots of ground noise so it was partially triggering the coil past its duty cycle which caused it to burn out. There are 4 grounds off the ECU. Two of them were fine, but two of them when grounded separately the signal cleaned up. Picture below of the O-scope image, racecar in yellow, street Miata blue. The grounding points from the harness to the motor/chassis were all fine and had no impact on it. In the end I simply soldered another ground point to those wires and we went to the next race. So somewhere in the system there is poor wiring. Yes, Ballenger has all the FI plugs, but I'm not seeing the plugs or pins for the power side of things (to the fuse blocks). I have an email in to them. Quote Link to comment Share on other sites More sharing options...
cbhaywood Posted January 30, 2022 Report Share Posted January 30, 2022 I went down the fuse box wiring rabbit hole last year… My notes indicate that I sourced from cycleterminal.com ATC Fuse Box Terminal Sumi Sumi ATC 14-20 Female ATC Fuse Box Terminal Sumi Sumi ATC 12-14 Female May want to look there to see if you can find what you are looking for... Good Luck!! 1 Quote Link to comment Share on other sites More sharing options...
TimS Posted January 31, 2022 Report Share Posted January 31, 2022 I found several issues with the OEM wiring and fuse box. I found numerous broken and damaged wires, mostly ground wires. I’m not sure why oem harnesses have so many independent grounds but it can be difficult to track down problems. Racing just adds to the problem. I decided to remove nearly 100% of the factory harness. I only reuses the engine harness after a very detailed inspection. I found it easier to rewire than continue to track down broken and damaged wiring. Good luck on your wiring Quote Link to comment Share on other sites More sharing options...
turbogrill Posted January 31, 2022 Report Share Posted January 31, 2022 1 hour ago, TimS said: I found several issues with the OEM wiring and fuse box. I found numerous broken and damaged wires, mostly ground wires. I’m not sure why oem harnesses have so many independent grounds but it can be difficult to track down problems. Racing just adds to the problem. I decided to remove nearly 100% of the factory harness. I only reuses the engine harness after a very detailed inspection. I found it easier to rewire than continue to track down broken and damaged wiring. Good luck on your wiring The NC Miata ECU has like 5 (at least) ground wires to a ground point next to the brake booster (typical star ground I assume). I wonder if it's cheaper to have multiple ~18AWG wires instead of a a few thicker ones? Or maybe the many ECU grounds wires are various independent signal and power grounds? For instance the two heat elements in the O2 sensors are grounded via the ECU. On 1/29/2022 at 7:24 AM, MMiskoe said: The signal to the coil had a terrible profile, lots of ground noise so it was partially triggering the coil past its duty cycle which caused it to burn out. There are 4 grounds off the ECU. Two of them were fine, but two of them when grounded separately the signal cleaned up. Picture below of the O-scope image, racecar in yellow, street Miata blue. The grounding points from the harness to the motor/chassis were all fine and had no impact on it. In the end I simply soldered another ground point to those wires and we went to the next race. So somewhere in the system there is poor wiring. Yes, Ballenger has all the FI plugs, but I'm not seeing the plugs or pins for the power side of things (to the fuse blocks). I have an email in to them. Interesting, what do you mean by "grounded separately". So do you think the 2 of the ground wires might be broken internally? Quote Link to comment Share on other sites More sharing options...
TimS Posted January 31, 2022 Report Share Posted January 31, 2022 The bmw would use a separate ground for nearly every load or sensor. Some would be grouped together at the same termination point but lots of wires. Easy for one sensor to loose its path and all the rest to be good. I consolidated and grouped things together. So it will be easier to troubleshoot. Quote Link to comment Share on other sites More sharing options...
Team Infiniti Posted January 31, 2022 Report Share Posted January 31, 2022 All stock wires here, not sure Nissan is doing anything worth complementing, but have only had one original wire bite our ass, the alt excite wire lost some tape over the years, got a loop in it, turned into a kink that eventually broke, mid-wire, several inches from the alt. Repairs or add on-s are done with generic red/blue/yellow butt connectors & Harbor Freight crimpers....a zero fail rate, the only soldered repair is limited to the cam/crank sensor. To me, its not worth 15-25lbs to go down the rewire rabbit hole. Quote Link to comment Share on other sites More sharing options...
MMiskoe Posted January 31, 2022 Author Report Share Posted January 31, 2022 Having been into the wire harness both physically and in the diagrams, the grounding makes little sense. They have things that start on the RH side of the engine bay, go through the firewall, across to the LH side of the dash, then ground. They have ground lugs with multiple wires in (no problem), but they also have what amounts to a junction connector in-line where 6 wires all come together and there is a buss-bar inside a plastic housing. As far as the issues that started it, there are 4 wires out of the back of the ECU. With the o-scope hooked up and the car idling, if I stuffed a grounded wire down the backside of the plug two of them had no affect. the other two the signal cleaned up when I added this ground. None of the grounds on the chassis were suspect, I checked all of them. So I suspect it is an issue with either a plug or a wire. The factory harness is now sitting on the bench, its not going back in. What I am lacking now is plugs. Most of the FI system I ordered from Ballenger last night. But I'm lacking things like the plug for the fan, brake light switch, the power off the main fuse block under the hood etc. Not quite sure how to address those parts. 2 Quote Link to comment Share on other sites More sharing options...
Technical Advisory Committee mcoppola Posted January 31, 2022 Technical Advisory Committee Report Share Posted January 31, 2022 2 hours ago, MMiskoe said: Having been into the wire harness both physically and in the diagrams, the grounding makes little sense. They have things that start on the RH side of the engine bay, go through the firewall, across to the LH side of the dash, then ground. They have ground lugs with multiple wires in (no problem), but they also have what amounts to a junction connector in-line where 6 wires all come together and there is a buss-bar inside a plastic housing. As far as the issues that started it, there are 4 wires out of the back of the ECU. With the o-scope hooked up and the car idling, if I stuffed a grounded wire down the backside of the plug two of them had no affect. the other two the signal cleaned up when I added this ground. None of the grounds on the chassis were suspect, I checked all of them. So I suspect it is an issue with either a plug or a wire. The factory harness is now sitting on the bench, its not going back in. What I am lacking now is plugs. Most of the FI system I ordered from Ballenger last night. But I'm lacking things like the plug for the fan, brake light switch, the power off the main fuse block under the hood etc. Not quite sure how to address those parts. Would you feel comfortable with using the connectors and a couple inches of wire off the oem harness and soldering to them? Quote Link to comment Share on other sites More sharing options...
MMiskoe Posted January 31, 2022 Author Report Share Posted January 31, 2022 Soldering no. Crimping yes. For some of them that is likely what I’ll do. Things like the fan and brake light switch I’d rather avoid fabbing new parts so I’d turn the existing leads into a pigtail to graft on the new harness. 1 Quote Link to comment Share on other sites More sharing options...
Robmink Posted February 1, 2022 Report Share Posted February 1, 2022 Can you send close up (legible!) pictures of any writing on the connector housings in question? Quote Link to comment Share on other sites More sharing options...
MMiskoe Posted February 2, 2022 Author Report Share Posted February 2, 2022 The TPS is the one I really need. The power parts I've resolved myself to buy new fuse and relay boards that use new connectors. Here's the 4-pin TPS plug. It has 10711 on the back, also says AMP on the opposite side of the wires. Quote Link to comment Share on other sites More sharing options...
turbogrill Posted February 2, 2022 Report Share Posted February 2, 2022 (edited) 1 hour ago, MMiskoe said: The TPS is the one I really need. The power parts I've resolved myself to buy new fuse and relay boards that use new connectors. Here's the 4-pin TPS plug. It has 10711 on the back, also says AMP on the opposite side of the wires. Looks like somoitu hv 040 https://www.bmotorsports.com/shop/popup_image.php/pID/3338/inum/2 NVM, it's different. Maybe this one? https://www.ebay.com/itm/112802311576?chn=ps&norover=1&mkevt=1&mkrid=711-117182-37290-0&mkcid=2&itemid=112802311576&targetid=1263104805526&device=m&mktype=&googleloc=9029719&poi=&campaignid=14859008593&mkgroupid=130497710760&rlsatarget=pla-1263104805526&abcId=9300678&merchantid=138366168&gclid=Cj0KCQiA0eOPBhCGARIsAFIwTs5mECo5qemwvWhQxEwgt6nRreoNYKEqB2akySUOdzYIdAJBMk85AnIaAvb5EALw_wcB Edited February 2, 2022 by turbogrill 1 Quote Link to comment Share on other sites More sharing options...
TimS Posted February 2, 2022 Report Share Posted February 2, 2022 (edited) Looks to be a very common oem connector. https://m.fuelinjector-connectors.com/sale-11426537-tyco-amp-ssc-series-4-pin-tps-throttle-position-sensor-connector-plug-90980-10711-184046-1.html Get yourself a good crimping tool and wire stripping tool. It makes it so much easier to build these connectors and plugs. They aren’t expensive but they are big time saver Edited February 2, 2022 by TimS Quote Link to comment Share on other sites More sharing options...
MMiskoe Posted February 3, 2022 Author Report Share Posted February 3, 2022 Thanks guys. Turbogrill - yes, that first one is not quite right, the housing is missing some details. Second one looks like a winner. Tim - also looks like the right one, but I only need one, not 500. I've got some good strippers. Even bought my teenager a pair for Christmas. (how many 17 year old boys can say their parents got them strippers for Christmas?) Also have a pair of crimpers, not top of the line, but they work. Staying away from Deustch connectors because those crimps are so specialized. 1 Quote Link to comment Share on other sites More sharing options...
BeastZ06 Posted February 4, 2022 Report Share Posted February 4, 2022 https://4rcustomswire.com These folks probably have a similar color wire if you want to buy new, but match the OEM wiring harness. Quote Link to comment Share on other sites More sharing options...
TimS Posted February 10, 2022 Report Share Posted February 10, 2022 https://www.amazon.com/gp/product/B087M56CDB/ref=pe_2313360_623839830_em_1p_0_lm popped up in my email today. I hope your rewire project is going well. Quote Link to comment Share on other sites More sharing options...
MMiskoe Posted February 10, 2022 Author Report Share Posted February 10, 2022 Funny, small internets. So the 4-way plug you posted the other day, I used the PN, did some searching, found it on Amazon, it arrived and fits. I ordered something else from Ballenger either that same evening or within a couple of days. Would have gladly given them the business had I known. Man there is a lot of wire in one of those cars! That's everything from the seats forward. 1 Quote Link to comment Share on other sites More sharing options...
craig71188 Posted February 11, 2022 Report Share Posted February 11, 2022 Another source for OE style connectors and wiring "stuff" - Standard Motor Products. PDF catalog of wiring "stuff": https://www.pageturnpro.com/Four-Seasons/73236-2015-Standard-Wire-Cable-Illustrated-Parts-Guide/sdefault.html#page/1 Illustrated connector guide (by terminal count): https://www.standardbrand.com/media/1514/st11211-illustrated-connector-guide.pdf You can get multiple views if you pull these up by part number on the website. Lots of this stuff is stocked by warehouses on Rock Auto - just search by part number. 2 Quote Link to comment Share on other sites More sharing options...
MMiskoe Posted February 11, 2022 Author Report Share Posted February 11, 2022 That is a great pair of items. Maybe someday I can meet the guys who think these things up and I'll buy them a beverage while they explain why each widget needs its own special plug. Quote Link to comment Share on other sites More sharing options...
turbogrill Posted February 11, 2022 Report Share Posted February 11, 2022 2 hours ago, MMiskoe said: That is a great pair of items. Maybe someday I can meet the guys who think these things up and I'll buy them a beverage while they explain why each widget needs its own special plug. Call me and I buy one as well. Quote Link to comment Share on other sites More sharing options...
TimS Posted February 12, 2022 Report Share Posted February 12, 2022 OEM wiring harnesses make my head hurt. Lots of extra and redundant wire in my opinion. It no wonder electrical issue on cars are so difficult to fix. The special plugs and connector just add extra fun to everything 1 Quote Link to comment Share on other sites More sharing options...
atxe30 Posted February 13, 2022 Report Share Posted February 13, 2022 i absolutely rip all oem wiring out and do the mil-spec racing reload.....e-gremlins blow...... 1 Quote Link to comment Share on other sites More sharing options...
turbogrill Posted February 14, 2022 Report Share Posted February 14, 2022 17 hours ago, atxe30 said: i absolutely rip all oem wiring out and do the mil-spec racing reload.....e-gremlins blow...... I think there are 3 options: 1. Keep OEM wiring and remove stuff like seat heater harness and other obvious things 2. Strip out OEM harness and relocate fuses boxes and stuff. 3. Aftermarket ECU with harness Option 2 is what I am doing and it's by far the worst option Option3 is actually fun and interesting, option2 is just tedious with so so results. Quote Link to comment Share on other sites More sharing options...
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