Do you sell a fixed version of the harness ready to go? Appreciate your time thanks man Great video, best one on what’s going on with these harnesses and how to fix them!
First of all, thank you! I don't fix these for the public, with my shop rate and time involved you will have the same invested as an American made harness. This video is geared toward the DIY type that wants to tackle this themselves. Good luck on your swap!
lots of good info-thanks for posting! my china dbc t56 harness had the vss signal stuck in #41 red (should be #21 red,), the tps stuck in #8 blue (should be #46 blue), and the map stuck in #48 blue (should be #47 blue) as well as the tach wire wired into hot as well
have'nt fired up motor yet-my advice to anyone buying one of these harnesses is to download the pcm pinouts on lt1.com & trace every wire to make sure they are in the correct locations on the pcm plugs. also my fuel pump relay wires were switched (85 & 86) and main relay grd & ecu pwr (85 & 87) were switched
I'm glad you made this video, I bought a harness from a place called high performance injectors which claim to be made in the U.S, but it looks exactly the same as your harness. I'll be taking a good look at mine before installing it.
Hey I bought one from the same seller ( LS3 gen 4 with manual transmission) and it's all good. Just went through and tested it. I would like to point out they are using PSI conversions instruction manual ( that doesn't match their own fuse/relay block ) nor is any of the fuses marked at all. I'm seriously questioning the wire used as well as the connectors at this point. I bought a BP automotive DIY harness and wanted to do my own stand alone harness but the original harness was just too brittle and rough. If I had it to do over I would simply buy the PSI Conversions harness and just modify it to fit my needs. I do not want my ECM under the dash as I have Vintage air going in and the Dakota digital gauges module, along with a brand new American Autowire classic update kit. Guess I'm the only one who wants all my fuses and relays in one place eh?
I just went thru this on my Amazon harness. Found 11 wires mis pinned. I had to move all the pins around and fix it. Also found my FAN 2 wire completely missing. I ran a new one. Amazon harnesses are notorious for having mis pin issues.
FYI My boy bought a 2014 Chev Traverse with a bad trans , when I unhooked the battery the harness had a tag that said Made in China on it . Now I bought one of these LS swap harness and it looks just like the harness on that Traverse . We looked for any difference between the LS swap harness and that GM harness damm if we could see any difference , the wire , connectors, loom and tape were identical .
@@alphathefirstone1222I bet it was Karl Kustom. Haven’t bought one from them but considering it. I’m on the fence as to either buy a painless harness, rework two that I have from the junk yard or buy cheap China one…
Thankyou I have had nothing but problems with mine hopefully my last issue is the o2s drivers side works fine passenger side is not. Now I know what to look for.
@ATCPLLC hey bud my problem ended up being that I somehow mixed the correct v8 pcm with a v6 pcm that I had on the same shelf lol. Plugged in the correct pcm and everything is good now
Thanks I found the problem to my o2 sensors. The only problem I’m having still is my trans temp gauge is not reading correctly. It’s getting a -14 reading I installed a new sensor and still no fix any ideas??
I saw this video too late. I plugged my brand new Bosch o2’s in and now I’m catching p0135 and p0155 even AFTER doing the fix. I checked resistance across the heater circuit and viola, OL. So I fried both heater circuits on the o2’s? Someone asked about it previously but how do these get fried like that?
Thank you very much for this video it was very detailed... I have get that same harness about 2 years ago and I installed the harness not knowing their was problem with it I finished my stage 2 cam with turbo setup project couple weeks ago,, the problem I am getting it will start but runs like crap foul the spark very easy, on the Hp tune scanner the map read 105 kpa just plugged in and no 02 reading,,I have not gotten the chance yet to check and compare the harness with the video. I am hoping the harness is the problem, how about the map and 02 sensor do I need to replace them? if the wire harness is correct what is my next move?
I have a similar engine ls3, I did the electrics as you have in the video. We programmed the computer and turned off the "vats system". Unfortunately, the engine did not start. High voltage comes to the spark plugs, but no impulse comes to the injectors. Maybe you can advise me what could be the reason. Diagnostics shows me the error P0315. The sensor is working. Thank you very much in advance
As for the 02 sensors, is it possible that the wiring could be wrong causing my swap to run terrible when the 02’s are plugged in? Great video by the way!
It's possible, would be pretty easy to tell by looking at the fuel trims/ O2 sensor data on a scanner. I think anyone swapping should consider even a simple scanner such as the torque app as a standard necessity for troubleshooting
How an or why do they fry O2 sensor I bought one couldn’t get any O2 sensors on my HPtuners they heated up but no long or short term fuel trims . I had stock harness before O2s worked ripped the swap harness out stock back In still nothing . So I’m guessing the swap harness fried all 4 O2 sensors I tried ?
@@vincequast8745 hard to say, I'd compare the old harness pinouts to the new one by continuity testing, sounds like there's some wires transposed there...
I have a question basing my build off ur LS1 DBCable "96-99OBS LS Swap" vid with the Ford shroud/mechFan but w/ "ProperPerformance MidLength headers". Bit nervous cus I can take days 2 prep but I'd have 2 secretly pull out old 350 & mount (Doesnt've run same day just hood closed) LS1 same day. Idk which LS1 motor mount 2 use considering "fuel system 99 vortec stock w/ a Return style rail off a 99-02 truck" (mentioned in ur 96-99OBS LS vid) @HsPerformanceWi what would u recommend? Ty!
You ever find any problems with the Dbw ones. I just ordered one and it immediately sets p0220 and p2135 codes. I’ve tried different pedals with the tac that came out vehicle with it. 2 pcms lol. Just wondering if it might be in the harness now like you show on some these vids. Also if do know anything wrong how much to send to you and fix and ship back. 😁. Thanks in advance.
I have a dbw p59 here in a project but I haven't gotten it to the point of powering it up yet and might be a while. I'll certainly make another video if I come across any issues
@@HsPerformanceWi I got schematic off net for my tac and throttle body. Done the continuity test and found that one pin in the tac controller connection was totally out of socket. Guess quality control missed that one and looks like they made all changes already that you have in vid on rest of the harness. Thanks in advance for your vids.
After looking at countless harnesses on eBay and Amazon, I have come to the conclusion they are all mislabeled. Wrong MAF plugs, wrong fuel injector plugs, wrong PCM connectors. Mislabeled Vortec engine. Saying it is for a Vortec when it is for an LS and so on. Then you either have to modify the harness or buy adapters. Then I found out the adapters are made with CCA cables which are GARBAGE. I found a small company in the USA making them with solid copper, correct MAF plug and correct fuel injector plugs for a Vortec. Cost about $100 more but worth it in the end. Its the correct cable with the correct plugs and made here in the USA.
@@HsPerformanceWi After receiving my harness today in the mail I was TOTALLY disappointed. This a cheap Chinese harness you can buy for $100 with the CCA fuel injector adapters and 3 wire MAF sensor wire with adapter. HPI Injectors is a complete ripoff. Sorry for the mis information
you should have some MAP/baro codes present, but not always. You can do a sanity check with a scanner that reads live data. with key on engine off the manifold absolute pressure should read close to 99 Kpa depending on what elevation you live at
@@HsPerformanceWi this has to be why my swap aint starting got fuel spark.all tested..but I have same harness and to late now..and no codes are popin up
Do you sell a fixed version of the harness ready to go?
Appreciate your time thanks man
Great video, best one on what’s going on with these harnesses and how to fix them!
First of all, thank you! I don't fix these for the public, with my shop rate and time involved you will have the same invested as an American made harness. This video is geared toward the DIY type that wants to tackle this themselves. Good luck on your swap!
this is gold.Thank you for sharing your knowledge, it came in clutch.
lots of good info-thanks for posting! my china dbc t56 harness had the vss signal stuck in #41 red (should be #21 red,), the tps stuck in #8 blue (should be #46 blue), and the map stuck in #48 blue (should be #47 blue) as well as the tach wire wired into hot as well
also map grd (#60 blue) and tp grd (#54 blue) were switched-lol
What would your car do because of the witched wires? Did it run or not at all
have'nt fired up motor yet-my advice to anyone buying one of these harnesses is to download the pcm pinouts on lt1.com & trace every wire to make sure they are in the correct locations on the pcm plugs. also my fuel pump relay wires were switched (85 & 86) and main relay grd & ecu pwr (85 & 87) were switched
I'm glad you made this video, I bought a harness from a place called high performance injectors which claim to be made in the U.S, but it looks exactly the same as your harness. I'll be taking a good look at mine before installing it.
the harness in this video came from the same seller!
@@HsPerformanceWi Yep I looked at it today, and I see the same issues! I'll be going over it just like you did. Hopefully it works out.
@@CountyGarage207 Glad I could help, makes the videos worth making
Hey I bought one from the same seller ( LS3 gen 4 with manual transmission) and it's all good. Just went through and tested it.
I would like to point out they are using PSI conversions instruction manual ( that doesn't match their own fuse/relay block ) nor is any of the fuses marked at all. I'm seriously questioning the wire used as well as the connectors at this point. I bought a BP automotive DIY harness and wanted to do my own stand alone harness but the original harness was just too brittle and rough. If I had it to do over I would simply buy the PSI Conversions harness and just modify it to fit my needs. I do not want my ECM under the dash as I have Vintage air going in and the Dakota digital gauges module, along with a brand new American Autowire classic update kit. Guess I'm the only one who wants all my fuses and relays in one place eh?
You saved me man. Thank you for your awesome video. Had the o2 issue
I cannot thank you enough for this.
Great video ... the leg of the harness .... that goes under the dash ... i have some wires thats ... not on the instructions ...
THANK YOU SO MUCH FOR POSTING THIS!
I just went thru this on my Amazon harness. Found 11 wires mis pinned. I had to move all the pins around and fix it. Also found my FAN 2 wire completely missing. I ran a new one. Amazon harnesses are notorious for having mis pin issues.
FYI My boy bought a 2014 Chev Traverse with a bad trans , when I unhooked the battery the harness had a tag that said Made in China on it . Now I bought one of these LS swap harness and it looks just like the harness on that Traverse . We looked for any difference between the LS swap harness and that GM harness damm if we could see any difference , the wire , connectors, loom and tape were identical .
@@alphathefirstone1222I bet it was Karl Kustom. Haven’t bought one from them but considering it. I’m on the fence as to either buy a painless harness, rework two that I have from the junk yard or buy cheap China one…
Thankyou I have had nothing but problems with mine hopefully my last issue is the o2s drivers side works fine passenger side is not. Now I know what to look for.
Did you ever solve this? My o2s do nothing
@shawtygarage9056 I haven't had a chance to fix it yet been way to busy. Hopefully soon I'll be able to look for it.
Any problems with the crankshaft and camshaft sensor connectors? Mine seems to just shoot spark at every revolution and won't crank up.. im stumped
I'm having the EXACT same issue and was curious if it was wired right, did you ever fix the issue ?
@ATCPLLC hey bud my problem ended up being that I somehow mixed the correct v8 pcm with a v6 pcm that I had on the same shelf lol. Plugged in the correct pcm and everything is good now
How can they even sell these if they are all wonky like this. I thought I got lucky for my budget build but now I’m thinking I should wait
how do i see if the injectors are shorted to the ground wire in the back
Thanks I found the problem to my o2 sensors. The only problem I’m having still is my trans temp gauge is not reading correctly. It’s getting a -14 reading I installed a new sensor and still no fix any ideas??
I saw this video too late. I plugged my brand new Bosch o2’s in and now I’m catching p0135 and p0155 even AFTER doing the fix. I checked resistance across the heater circuit and viola, OL. So I fried both heater circuits on the o2’s? Someone asked about it previously but how do these get fried like that?
Thank you very much for this video it was very detailed...
I have get that same harness about 2 years ago and I installed the harness not knowing their was problem with it I finished my stage 2 cam with turbo setup project couple weeks ago,, the problem I am getting it will start but runs like crap foul the spark very easy, on the Hp tune scanner the map read 105 kpa just plugged in and no 02 reading,,I have not gotten the chance yet to check and compare the harness with the video. I am hoping the harness is the problem, how about the map and 02 sensor do I need to replace them? if the wire harness is correct what is my next move?
If the map is wired wrong it will ruin the sensor, the o2 sensors will be ok. You will need tuning regardless with the cam
Im having a problem with mine. Truck won't start and ground at pcm has 5v of power. Any thoughts?
verify pinout locations, only way to know
Mine has 2 tach wires in underdash bundle...have you seen that
Never seen that, trace it back to it's source and find out.
My ls has been surging like crazy at around 1500 but idles fine I’m starting to think that the map is wired wrong like this one
Thank you for doing this. I just bought a harness for a 03-06 (blue Green connector) would this still apply?
the p59 harnesses I have used have been without issue
also noticed your harness is like mine in that the blue 75 wire (pink pcm ignition supply) is missing. i guess you don't need it?
Good catch! I hadn't noticed that, I wonder if the others were the same. Knowing it now I would tie it in with blue 19 just to be safe
I have a similar engine ls3, I did the electrics as you have in the video. We programmed the computer and turned off the "vats system". Unfortunately, the engine did not start. High voltage comes to the spark plugs, but no impulse comes to the injectors. Maybe you can advise me what could be the reason. Diagnostics shows me the error P0315. The sensor is working. Thank you very much in advance
it sounds like you have a 58x crank reluctor ls3 that you are trying to use on 24x harness/computer
As for the 02 sensors, is it possible that the wiring could be wrong causing my swap to run terrible when the 02’s are plugged in? Great video by the way!
It's possible, would be pretty easy to tell by looking at the fuel trims/ O2 sensor data on a scanner. I think anyone swapping should consider even a simple scanner such as the torque app as a standard necessity for troubleshooting
@@HsPerformanceWi I definitely will when I get some time home man! I appreciate it!!
Are the red wires that go to starter terminal fused near those ends? That could be dangerous if not.
I bought this same harness and hooked everything up to spec then found out I didn't have power to my obd2 port
hows the quality of wire used? any worry about them being too thin?
The wire, insulation, and connectors are nowhere near OEM quality. Reliability over the long term is still unknown.
How an or why do they fry O2 sensor I bought one couldn’t get any O2 sensors on my HPtuners they heated up but no long or short term fuel trims . I had stock harness before O2s worked ripped the swap harness out stock back In still nothing . So I’m guessing the swap harness fried all 4 O2 sensors I tried ?
I had stock harness last year an everything worked
@@vincequast8745 hard to say, I'd compare the old harness pinouts to the new one by continuity testing, sounds like there's some wires transposed there...
@@HsPerformanceWi I have done continuity test all wires going to the pcm for pins for high low Signal for both banks
O2 heaters are also working but no reading
@@vincequast8745 aftermarket sensors are known to have reference and grounding issues, something to consider if they've been replaced
Are my starter wires
@HsPerformanceWi or Any1 tried/heard of AZProperPerformance 580$ LS harnesses?😅 Is it closest plug&play? 99 2dr 4wd Tahoe 6" RoughCountry Lift 4l60e
I have a question basing my build off ur LS1 DBCable "96-99OBS LS Swap" vid with the Ford shroud/mechFan but w/ "ProperPerformance MidLength headers". Bit nervous cus I can take days 2 prep but I'd have 2 secretly pull out old 350 & mount (Doesnt've run same day just hood closed) LS1 same day. Idk which LS1 motor mount 2 use considering "fuel system 99 vortec stock w/ a Return style rail off a 99-02 truck" (mentioned in ur 96-99OBS LS vid) @HsPerformanceWi what would u recommend? Ty!
My eBay harness is not getting Spark from the coil packs I know it’s not the grounds it Hass to be the harness
You ever find any problems with the Dbw ones. I just ordered one and it immediately sets p0220 and p2135 codes. I’ve tried different pedals with the tac that came out vehicle with it. 2 pcms lol. Just wondering if it might be in the harness now like you show on some these vids. Also if do know anything wrong how much to send to you and fix and ship back. 😁. Thanks in advance.
I have a dbw p59 here in a project but I haven't gotten it to the point of powering it up yet and might be a while. I'll certainly make another video if I come across any issues
@@HsPerformanceWi I got schematic off net for my tac and throttle body. Done the continuity test and found that one pin in the tac controller connection was totally out of socket. Guess quality control missed that one and looks like they made all changes already that you have in vid on rest of the harness. Thanks in advance for your vids.
After looking at countless harnesses on eBay and Amazon, I have come to the conclusion they are all mislabeled. Wrong MAF plugs, wrong fuel injector plugs, wrong PCM connectors. Mislabeled Vortec engine. Saying it is for a Vortec when it is for an LS and so on. Then you either have to modify the harness or buy adapters. Then I found out the adapters are made with CCA cables which are GARBAGE. I found a small company in the USA making them with solid copper, correct MAF plug and correct fuel injector plugs for a Vortec. Cost about $100 more but worth it in the end. Its the correct cable with the correct plugs and made here in the USA.
please share the supplier!
@@HsPerformanceWi After receiving my harness today in the mail I was TOTALLY disappointed. This a cheap Chinese harness you can buy for $100 with the CCA fuel injector adapters and 3 wire MAF sensor wire with adapter. HPI Injectors is a complete ripoff. Sorry for the mis information
bummer@@richardmiller3781
cant ya just use a harness from the donor truck?
Yes, If that's what you wish to do.
Don't blindly use this it is 3 years old so check your harness to pinouts before doing any harness!
How do you kno if you fried map sensor
you should have some MAP/baro codes present, but not always. You can do a sanity check with a scanner that reads live data. with key on engine off the manifold absolute pressure should read close to 99 Kpa depending on what elevation you live at
@@HsPerformanceWi this has to be why my swap aint starting got fuel spark.all tested..but I have same harness and to late now..and no codes are popin up
@@HsPerformanceWi 6.0 2003 caddy motor swap to 70 elco
@@senecahenderson9240 One costomer's I fixed would run, but they had to peddle it to get it started, wouldnt idle and ran super rich
@@HsPerformanceWi also I put a .550 stage 2 cam..just try to find out I can on this no start but turns over