which wires are sensitive to resistance?
07-27-2009, 10:44 PM
#1
which wires are sensitive to resistance? i plan on doing some major rewiring of things so that i can clean the car up a bit. mainly i would like to extend all the wires that go to the fuseboxes in the engine bay so i can relcate that mess of crap! anything on those fuse boxes sensitive to resistance?
also i have a few gauge sensor wires i need to extend so i can be able to actually connect them (n20 pressure and fuel pressure). any of these wires sensitive?
i do plan to solder most if notall connections but still would like to know what to be careful with so i dont run into any future electrical problems.
thanks for any help
also i have a few gauge sensor wires i need to extend so i can be able to actually connect them (n20 pressure and fuel pressure). any of these wires sensitive?
i do plan to solder most if notall connections but still would like to know what to be careful with so i dont run into any future electrical problems.
thanks for any help
07-28-2009, 07:07 AM
#2
Any time you extend wires in a circuit, you will increase the resistance in that circuit.
Given that many of the sensors on the car measure resistance, doing this work could be a recipe for many many future gremlins. (Unless you have the system re-engineered.)
Some circuits may not be a problem, but others might be.
Given that many of the sensors on the car measure resistance, doing this work could be a recipe for many many future gremlins. (Unless you have the system re-engineered.)
Some circuits may not be a problem, but others might be.
07-28-2009, 11:45 AM
#5
I'd suggest looking for other methods to clean up the wiring. If you still want to go through with it, I'd suggest the following. A factory-grade harness job will require some investment in tools/resources. Without these tools, the longevity of your project will be negatively impacted.
- Don't touch anything Yellow no matter what. (These wires are related to the air bags.)
- Remember that soldering will improve a connection, but will not bond wires together. You can purchase GM Wiring Repair Tools and use Delphi splice clips and insulated splice connectors to do your connections. Some of these also call for solder and will give you a connection many orders of magnitude stronger than other crimps or solder alone. The tools can be had for reasonable prices on eBay and there are several places where you can get the clips. All of the tools, clips, methods, etc. can be found in this book: http://www.weber.edu/wsuimages/autom...%20Booklet.pdf (Pages 9-19 will be of most interest to you - but the whole thing should be your bible.)
- Get a set of GM Factory Service Manuals. They come in a green 3 book set and are published by Helm. Again, you can usually get good prices on dealer liquidations on eBay. (Or you can get spankin' new ones from Helm.) These manuals have schematics for every circuit in the car and will help you understand what you are working with. The schematics also tell you what gauge wires you are working with.
- Use the manuals above to find if you are extending circuits for resistive sensors. If you extend these by long distances, you may increase the gauge of the entire run.
- Don't use wire from your local hardware store, autoparts store, or Radio Shack. If you want to do a quality job, you'll need to hunt down a good automotive wiring supplier. Like airplanes, cars require special wire insulation to stand up to the operating environment. If you use cheap wire, then you'll get cracking, shorts, etc. This is a good article which describes some of the types: http://www.kayjayco.com/catPWireSelect.htm
If you decide to get in to the Delphi connectors and tools, feel free to let me know. I have a number of other resources where connectors/parts can be found. The other nice thing about using the Delphi connectors and tools is that in some places, you can replace entire wires connector-to-connector with longer runs and eliminate splices.
- Don't touch anything Yellow no matter what. (These wires are related to the air bags.)
- Remember that soldering will improve a connection, but will not bond wires together. You can purchase GM Wiring Repair Tools and use Delphi splice clips and insulated splice connectors to do your connections. Some of these also call for solder and will give you a connection many orders of magnitude stronger than other crimps or solder alone. The tools can be had for reasonable prices on eBay and there are several places where you can get the clips. All of the tools, clips, methods, etc. can be found in this book: http://www.weber.edu/wsuimages/autom...%20Booklet.pdf (Pages 9-19 will be of most interest to you - but the whole thing should be your bible.)
- Get a set of GM Factory Service Manuals. They come in a green 3 book set and are published by Helm. Again, you can usually get good prices on dealer liquidations on eBay. (Or you can get spankin' new ones from Helm.) These manuals have schematics for every circuit in the car and will help you understand what you are working with. The schematics also tell you what gauge wires you are working with.
- Use the manuals above to find if you are extending circuits for resistive sensors. If you extend these by long distances, you may increase the gauge of the entire run.
- Don't use wire from your local hardware store, autoparts store, or Radio Shack. If you want to do a quality job, you'll need to hunt down a good automotive wiring supplier. Like airplanes, cars require special wire insulation to stand up to the operating environment. If you use cheap wire, then you'll get cracking, shorts, etc. This is a good article which describes some of the types: http://www.kayjayco.com/catPWireSelect.htm
If you decide to get in to the Delphi connectors and tools, feel free to let me know. I have a number of other resources where connectors/parts can be found. The other nice thing about using the Delphi connectors and tools is that in some places, you can replace entire wires connector-to-connector with longer runs and eliminate splices.
07-28-2009, 08:18 PM
#6
None of the wires you mentioned will be that sensitive to resistance that a longer wire will make a difference. Certainly, a power or ground wire is nothing to worry about. For example, the 14 gauge wire commonly used for much of the factory harness adds about 0.00297 ohms per foot. You would have to add 200 feet of wire in one circuit to add a miniscule 1/2 ohm of resistance. Even 16 gauge adds only 0.00473 ohms per foot. The connectors you use will add much more resistance than that.
Resistive sensor wires are more sensitive, of course. But adding a couple of feet of the proper gauge wire won't increase the resistance enough to cause a problem - the sensors are not that sensitive. Just don't add any more than you have to and make sure your connections are solid. It's better to replace a section of wire that has multiple splices with a single piece of wire without extra splices wherever possible.
Resistive sensor wires are more sensitive, of course. But adding a couple of feet of the proper gauge wire won't increase the resistance enough to cause a problem - the sensors are not that sensitive. Just don't add any more than you have to and make sure your connections are solid. It's better to replace a section of wire that has multiple splices with a single piece of wire without extra splices wherever possible.
