harness wires
If a wire is not damaged, theres nothing wrong with reusing it. Be aware that whatever solder joint you put in needs to be high quality. If you are simply reusing a length of wire say between the PCM and a sensor, you will have 2+ solders over the span, each adding resistance to the circuit. You need to test this with a multimeter before you move on to be sure the joints dont give too much resistance. Also remember to use the same gauge wire. Mixing sizes leads to grief in an already involved project
My personal thresh hold is 1.2ohms. Beyond that, I cut the section out and redo it. As a point of reference, an unbroken 5' 20ga wire with OEM crimped on PCM terminal and sensor terminal on the other end is usually .7-.9ohms. For most sensors this isnt a big deal, but some are resistance based, such as the TPS. Then the bad solder joints will cause faulty readings and the PCM will over/under compensate the actual throttle position
Engine bay wiring is TXL jacket stranded. Several sponsors on the board sell it by the foot. I like to buy in 500' rolls from ebay. Youll build 98% of the harness using 18 and 20ga wire. Fuel relay to pump is 14ga, most relay 12v and engine grounds are 12ga
Good luck
My personal thresh hold is 1.2ohms. Beyond that, I cut the section out and redo it. As a point of reference, an unbroken 5' 20ga wire with OEM crimped on PCM terminal and sensor terminal on the other end is usually .7-.9ohms. For most sensors this isnt a big deal, but some are resistance based, such as the TPS. Then the bad solder joints will cause faulty readings and the PCM will over/under compensate the actual throttle position
Engine bay wiring is TXL jacket stranded. Several sponsors on the board sell it by the foot. I like to buy in 500' rolls from ebay. Youll build 98% of the harness using 18 and 20ga wire. Fuel relay to pump is 14ga, most relay 12v and engine grounds are 12ga
Good luck
Teching In
Joined: Jun 2008
Posts: 39
Likes: 0
When I start my project, I'm going to redo the entire harness in the whole car, eliminate some things and reroute others. How many feet of wire is a good guestimate for this? The car is a 1998 Pontiac Grand Prix, and it's going to have an LQ4/4l80e in it, with plans to TT rear mount down the road. I'm only going to use two colors, red and black, and I'll be making my own wiring diagram.
As I'm thinking right now;
1000 feet each of 18 and 20ga.
500 each of 14 and 12ga.
and around 500 feet in multiple sizes of black (ground) wire.
Does that sound like enough, or am I going to need to budget more?
As I'm thinking right now;
1000 feet each of 18 and 20ga.
500 each of 14 and 12ga.
and around 500 feet in multiple sizes of black (ground) wire.
Does that sound like enough, or am I going to need to budget more?
Sounds great if you're opening a harness company. 500' of 18 and 20 should be more than enough to replace every wire in the car and then some. 50 feet or so of 12ga is enough
Thats engine, dash, interior, front and rear light harnesses
Wire is expensive, price out 500' of 12ga
Thats engine, dash, interior, front and rear light harnesses
Wire is expensive, price out 500' of 12ga
. can you do mine too .I have an 05 harness with ecu 
