Aftermarket harness......tips, suggestions.....
I need to order a harness for my 6.0 4L80E combo in my chevelle. Just wanted to see what people have had good luck with or bad luck with. I was leaning toward PSI.
Joined: Apr 2007
Posts: 330
Likes: 1
From: Chicago, Illinois (far south)
I have used both including Painless on various swaps. The only one I had a problem was with PSI. There was a heavy misfire under load during heavy and WOT. After spending just under a year attempting to figure it out trying different things, I finally gave into the advice of my tuning shop who was insistent on it being the harness. I pulled it and put in a Speartech. The problem was finally solved and with a much higher quality looking harness at that.
I've used Howell and Speartech. Both have worked well. I like the loom covering Howell uses. It's the braided type not the plastic convoluted stuff. The braided type loom cover looks so much better. I always buy the computer and harness from the same supplier so if there is an issue you only have to call one place for help.
Joined: Apr 2007
Posts: 330
Likes: 1
From: Chicago, Illinois (far south)
I've used Howell and Speartech. Both have worked well. I like the loom covering Howell uses. It's the braided type not the plastic convoluted stuff. The braided type loom cover looks so much better. I always buy the computer and harness from the same supplier so if there is an issue you only have to call one place for help.
Trending Topics
I had a painless LS1 harness with REAL PROBLEMS. three of the injector plugs were not crimped correct. They were crimped without the wires even stripped. These were the easy problems to fine.
The harder ones were on the transmission control wiring a couple of the wires were cut and then had heat shrink tubing put over them to hide what was done. I bought this harness new from JEG's .
When I asked Painless about it they said that JEG's must have done that,because they don't make mistakes.
The harder ones were on the transmission control wiring a couple of the wires were cut and then had heat shrink tubing put over them to hide what was done. I bought this harness new from JEG's .
When I asked Painless about it they said that JEG's must have done that,because they don't make mistakes.
Last edited by bigkat_83; Sep 1, 2018 at 08:05 PM.
I used Current Performance since at the time, they were the only ones who did s10 harnesses. I did my swap 7 years ago. I haven't had any issues with my harness at all, and it was some of the best $ I spent on my swap, that, and the Holley pan, that again, just came out at the time.
It’s already been mentioned but PSI, Speartech or BPAutomotive are the only vendors I would go with. Each is more than capable of delivering a quality product. To help narrow it down, I would suggest calling each one to talk about your needs. This will help you get an idea of their knowledge and customer service. It’s good to know these things before handing over your money, so you know what you’re in for in the unlikely event you’ll need support after your purchase.
Those that have used PSI, I see that it comes with a fused relay, vs Speartech comes with just a relay. Anyone have any input on this? Any other differences, theres about a $200 price difference as well.
Joined: Apr 2007
Posts: 330
Likes: 1
From: Chicago, Illinois (far south)
Which relay are you referring to? Fuel? If so, there is a fuse for it with Speartech as well. Some of the price difference can be from the additional components built into the Speartech harness as well as the wire covering material. Their harnesses have several additional 12v convenience wires (can be used for aftermarket gauges, etc.), tap up/down shift wiring, cruise control, AC pass through wiring (for compressor), etc. Again, I have used three of the harnesses mentioned here and am speaking from the personal experience I have had using them.










