Last winters project - 85 IROC Z (From Intro)

[zaut]

Splices or joints on the middle of a wire are used throughout the vehicle. Since the early 90's the sonic welded splice is the desirable process. The plant uses less solder which is a hazardous material. That’s out of the question for a repair on the car. Before that we used, the clip and dip process. You would crimp a steel splice clip on the wires then dip the splice in a little flux then a solder pot. The splice clip is only to hold the wires together until soldered. In the contact physics realm, solder is the ideal electrical connection. It is considered to be a zero resistance connection. Clip and dip is still used in certain application like large cable sizes and some OEM’s just don’t like sonic splices. So again solder the splice and you will have a good, long lasting connection. Your basic 50/50 flux core solder is all we used. Lately, they have been using lead free solder in the solder pots, but that is only because of EPA issues. Outside the passenger compartment, splices are sealed with heat shrink tubing with hot melt glue inside. You will get good sealing because as the tube heats up and shrinks, it forces the hot melt into the voids between the cables. Water, especially salt water, is bad for energized circuits. In the passenger compartment, where it is dry, you can use what we called splice tape. It was basically duct tape. But electrical tape is fine. The splice tape gives better abrasion resistance and is harder to get solder spikes or loose strands to poke through than electrical tape.
Tin coated cable is used only on SIR circuits because of the critical nature of that system. Basically you get a better crimp then a bare copper core. But it is still not as good as a soldered crimp. In the high production world, you don’t want to solder crimps, so for critical circuits, they use tin plated cable. In that same arena, they would use gold plated terminals. The terminals are selectively gold plated in the connection interface. You will see that on the terminals plugging into the airbag squib. This is not necessary for any engine control application. Probably the only other exotic connection would be the cable in oxygen sensors. It’s typically stainless because of the temperature. Those connections are welded (laser or resistance) at the sensor and crimped at the pig tail. I would not recommend crimping to that cable. I think you can solder stainless, but I have never done it.

[zaut]

Mark,
As far as terminals soldered in a connector, if you have the correct terminal, you should solder the cable core to the terminal. Normal automotive crimps have two sets of crimp wings. On set is for crimping to the cable core. Solder that crimp. The other wings are the insulation crimp wings. Those give strain relief to the core crimp. You should not crimp the insulation crimp very tight. All you need is three point contact between the insulation and the wings. You can add heat shrink over the whole insulation crimp and core crimp if it will fit in the connector. That will give added stain relief. For sealed connection systems, like everything under hood, you want to make sure the seal is not distorted by the insulation crimp. Those crimp wings should only snugly wrap around the seal. If you are adding a non-OEM connector in a wet area that is not a sealed connector, I would definitely recommend the heat shrink if possible over the crimps. To enhance the connection more, pack the connector with grease to keep moisture out. I am sure you have seen that on older bulkhead connectors. It’s messy but works. We used what we called skin over grease. It was very cheap grease that would get a dry film on the outside over time. Lamp sockets used white lithium grease. Now everything is sealed with silicone rubber weather seals.

[gregs78cam]

It’s typically stainless because of the temperature. Those connections are welded (laser or resistance) at the sensor and crimped at the pig tail. I would not recommend crimping to that cable. I think you can solder stainless, but I have never done it.

I have never had much luck soldering stainless O2 wires. Luckily not all O2 wires are stainless. Posi-Locks work reasonably well also. http://www.posi-lock.com/posilock.html

I was wondering how long it was going to take them to come up with these. http://www.posi-lock.com/positite.html

[Six_Shooter]

I have never had much luck soldering stainless O2 wires. Luckily not all O2 wires are stainless. Posi-Locks work reasonably well also. http://www.posi-lock.com/posilock.html

I was wondering how long it was going to take them to come up with these. http://www.posi-lock.com/positite.html

I got a few of those on a car once, one of the worst ideas I've ever seen put into production, next to Scotch Locks, which ARE, without question, the WORST idea for electrical to EVER be produced. I can't count the number of vehicle and component problems I've fixed because somebody used a Scotch lock.

The posi-locks would be good for a temporary repair to get you back home, but that's it.

I was going to suggest the '7730/SD swap as well, and an intake swap, seems most 383s fall on their face pretty early on in the power band when using a TPI style intake. To me they put the TPI on the wrong vehicles, they should have been used on the trucks due to their low end torque production, and limited power band.

Using the '165 ECM though, I would look at $6E code mask, it was the last and AFAIK most advanced code used in the '165, which many $32 and $32B users seem to swap to in the end. It was used in 1989 in the '165 ECM. This also eliminates the need for the cold start injector.

[EagleMark]

They actually look like a good design? Expensive per connection but looks good. But then once you have a human interput instructions who knows how it's going to work or last.

Thanks Zaut for all the very informative information!

I've never had an issue with twisting 2 wires together and soldering then shrink wrap or tining ends of wire and slipping them in a connector adding heat and some more solder and shrink wrapping. My real concern since you seem to have the knowledge was which would be better or even matter?

For crimping ends I have weatherpak crimp ends and the proper tool so it's always a proper crimp and never try to overcrimp or like somepeople do SQUISH the ends thinking tighter is better. If I can't get the rubber water tight seal I shrink wrap it, still never had an issue.

But man have I had issues with those cheap fix all crimp connectors and SQUISH tools... I wouldn't call them a crimp, just a crush or squish. I have a little set in each vehicle tool box I only use then for emergency temporary fix myself but because I take care of stuff it's usually to help fix someone elses rig. When ever I see one on a car it's the first place I look for problems and usually find it there. I've seen some that are actually dam near cut becuase of the improper crimp, right through the decrotive fancy plastic cover, through the connector and wire just barely hanging together... garbage!

Probably 25 years ago I had a full set of crimp connectors with tool from a freind at the phone company and a never ending supply of connectors. When you insert the wires and crimp it would break open a small tube of what I thought was silicone for a perfect water tight seal. Very nice stuff! But when you look to but those kinds of connectors today they are very expensive, so I solder.

[1project2many]

It's amazing to see differences between automakers' harnesses. Old Mercedes wiring is amazing in it's ability to be simple yet complex. While the circuits tend to be super simple and there's an abundance of redundant grounds, the connectors themselves have a lot of engineering behind them. Every pin is soldered to the wire, the insulation is sealed after solder is applied, and the connectors are designed to take up any strain on the wire so the pins don't have to. There's more trouble with solder on the early circuit boards supplied by outside vendors than with the actual harness. Toyota on the other hand does some bizarre stuff with redundant power feeds and relays that seem to be added as afterthoughts. Toyota likes tape, and lots of it. They like crimp connections with no solder, and often use brass crimps instead of steel. But they do a helluva job of sealing the connectors. I don't know if anaerobic bacteria could survive inside a Toyota wire splice. And every wire is wrapped to within inches of it's termination point. The harness holds it's shape so well it can stand on its own after being removed from a vehicle. Cutting a Toyota harness without damaging a wire is an excercise in patience.

The two largest problems I see with on vehicle repairs are caused by lack of support and lack of sealing. Lack of support occurs because a solid connection such as a crimp or solder joint causes motion in the harness to concentrate at the points on either side of the repair. The repair isn't flexible so the wires move more at the intersection. If the motion is excessive or is applied for a long enough period the wires will break. In fact, for many years GM said no crimp or solder repair was acceptable in an ABS harness due to the possibility of this type of failure. But shrink tubing can be used to reduce some of this motion. It stiffens the wires on either side of the repair and acts as a shock absorber or strain relief. Another good method I rarely see used is to tape a strain relief into the harness. Something as simple as a length of nylon tie taped to the wire across the splice can serve as a great strain relief and it will last for years.

Sealing might seem like a no-brainer but my experience repairing even OEM wiring tells me it requires some attention to detail. A crimp needs to be applied with proper tools. Many inexpensive crimpers for barrel or sleeve crimps have no stop and the jaws have sharp edges. This combination will pierce the plastic insulation of the crimp if squeezed too hard. Even if the ends of the crimp are sealed the breach caused by the crimper will allow oxidation and eventual failure. Then there's shrink tubing. Any hole or nick in shrink tubing is a potential entry point for moisture and improperly sized tubing won't shrink tightly against the wire. It's imperative to inspect the shrink tubing after heat's been applied as small damage points will become larger when the tubing shrinks. I also tend to prefer shrink tubing with adhesive. My favorite barrel type crimp connectors have a combination of adhesive and heat shrinkable insulation. Once heat is applied and the crimp insulation adheres to the wire insulation, the bond is so tight you will pull the wire insulation off the wire before you can pull the wire out of the connector. But very few of these products work well when multiple wires are put together in a crimp. The voids where the two wires lay side by side are just too small for adhesive or silicone barriers to fill completely. In that case you need a supplemental sealer. Grease can be a great choice. I used to get "Non-oxidizing Grease" back when I repaired vehicles at the telephone company but it's hard to come by these days. 3M Silicone paste works but it's liable to wash out in a short time and it's expensive. I sometimes get a thick lithium based grease that's designed to protect light sockets for using with an acid brush. Brush it on in quantity. I also use "liquid electrical tape" which is a brushable sealer that hardens in a few minutes. It can take several coats to get a good seal but as long as there's no metal exposed it will last for years. It has little resistance to abrasion however so tape should be applied for protection. Under no circumstances should cheap connectors be used. Some have aluminum barrels and they won't stay crimped no matter how hard you try. Others are thin enough the crimp will relax over time with thermal cycling. I'm not afraid to use steel fuel/brake tubing and properly applied harness tape to crimp and seal a multiple wire connection in a pinch. While it can be tough to get the tubing to crimp, when applied well it will last as long as the wires it's connected to.

One warning about using solder on large cables. Any high current draw or source (like a starter or large alternator) has the potential to heat the repaired area enough to melt the solder. Always apply solder in conjunction with a strong mechanical connection such as a crimped splice. This prevents the wires from coming apart in the event the unexpected occurs. Melted solder on car parts is bad, but a power wire falling against ground and dead shorting can be much worse.

FWIW GM service manual has very good repair procedures in beginning of electrical section.

Did someone ask a question about TPI??? :)

[zaut]

The posilock looks like a good connection system. It is an axial bolt together connection. Bolt type mechanical connections a very reliable because the torque induced compression will not stress relieve over time like a bad crimp. You won't see them as an OEM production part because of cost and slow assembly times. Cut and terminate machines "cutters" they are called make leads at rates up one per second. It's all about low cost, high quality and reliability. The GM service manual is an excellent source for repair instructions. I worked closely with the crimp technology group for years. You would be surprised how precise crimps need to be. For example the normal tolerance for crimp height is +/- 0.05 mm. On smaller cable like 0.26 mm2 its +/- 0.02 mm. Core crimp height is the critical dimension. Core crimp width is fixed by the crimp tool. One terminal can be validated for several cable sizes. Each cable-terminal combination will require specific crimp geometry and therefore tooling. Even if you have the correct crimp tool for the specific terminal, you should solder after crimping, because that tool is most likely for one cable size. You will never have to worry about it again. I have many different crimp tools and I always solder.
Packard builds harness for Mercedes and for Toyota. The same machines are used to cut and terminate for all OEM’s. Obviously Packard will try to sell Packard connection systems to make more money, but in the end, the OEM chooses the components. The biggest thing each wants is to take cost out. I worked for three years on a Toyota – aluminum cable project. I got three Patents out from it. That wiring will not be serviceable. We were scratching our heads on how to do it. But with copper going to $5/lbs and aluminum at $1/lbs, it is going to be used more and more!

[1project2many]

The FIRST manifolds and runners are larger than the SLP or other oversize stock replacements. Engines using near stock FIRST systems easily achieve 400+ hp. Again, it's a nice manifold but not a necessity.

I agree with Six_Shooter regarding the calibration of choice for the '165. If you use that ecm the best starting calibration is ARAP from the '89 model year. Make sure you use a wiring diagram matching the year calibration you choose to use. There are subtle differences between the early and late cars' configurations.

No worries. Even without the larger runners your car will leave the light faster than the average Joe. With the right rear gearing it will pull right up to the shift as well.

[zaut]

What vehicle is the ARAP for? And which mask is that for? I will look at that closly. Do know the Memcal part number I would need? I assume the memcal I just bought won't work with that mask ans BIN.
The car has a 3.42 posi. Even with the poor tune I have, I can't get the power to the ground. I think I will have to buy tires more often.