Project Lexus SC300 Road Racer: Part 10 – Finish Wiring the Back and Prep the Front Harness

Project Lexus SC300 Road Racer: Part 10 – Finish Wiring the Back and Prep the Front Harness

by Erik Jacobs


We finally had begun wiring Project SC300 in the last installment. With the main trunk harness mostly complete, it was time to start buttoning things up. We still had the matter of the wheel speed sensor harness to attend to and probably a few thousand other things, too.

The most successful race teams win their races off the track. Much how like airline pilots spend a tremendous amount of their practice time and study preparing for the potential ugly situations, races are won via extensive preparation, practicing and planning for problems. Since the majority of NASA’s ST-2 races in the South East region are sprint races, it means that there is not a lot of time during a race weekend for something to go wrong and be fixed. Helping make problems easy to diagnose is important, and in some ways, a simple thing like a label goes a long way. That’s where Dymo comes in.


You probably know Dymo for their hand-held home-type labelers or maybe the desktop label printers. But, Dymo does a lot in the industrial space, too.

Recently, Dymo released a new line of industrial labelers to go above and beyond the existing Rhino-brand lineup. These XTL labelers are targeted at hard-core industrial use cases. Think about computer data centers, manufacturing facilities, and so on and so forth. Conveniently enough, Dymo produces a range of label tapes that also meet milspec standards and offer them in a heat-shrink tube variety. Perfect!


The labelers come with neat carrying cases!

The XTL series are pretty large labelers. They feature rechargeable built-in batteries that last a really long time. They also offer USB connectivity to a PC so that they can be controlled from your computer. In a shop setting where you are producing a lot of wiring harnesses, that could be a useful feature.

The smaller XTL 300, on the right, also comes with a lanyard so that you could carry it around. I find that offering rather amusing because that thing is heavy. I certainly wouldn’t want to carry it around my neck all day. Then again, I carry 6+lbs of camera gear routinely, so…


Dymo offers a full spectrum of shrink tube sizes for the XTL series.

We have a lot of different size wiring bundles on this project. The harnesses on main circular milspec connectors going through bulkheads are quite big. The individual 2-pin connectors are pretty small, however, being able to cover the spectrum of wire bundle sizes is nice.

Two things to note: The XTL 300 cannot accommodate the full 2” wide label tapes. With a 3:1 shrink ratio, the 1/4“ label tape will not really shrink down small enough to be able to label an individual 20AWG milspec wire.

On the large side, you could use a regular milspec-rated label and then a larger piece of milspec-rated clear shink tube and spend less for the XTL 300. But, if you are doing a lot of harness work, it might make sense to spring for the XTL 500. The 500 is the big boy and really is desk-bound. Sure, you could bring it over to a car to do some work, but it’s by no means a “hand held” unit.

On the small side, labeling individual wires may or may not be important to you. It really just depends on how much time you want to spend and how anal you are. A multimeter in continuity test mode can “find” wires in a loom pretty quickly, provided both ends are available. It’s kind of a toss-up.

The other thing is that the Dymo labelers and the label tapes are quite pricey. There are other labelers on the market that have a much lower cost of entry, but they don’t go as large (2” tapes).


The labeler has some smarts and knows what tape cartridge is inserted.

Loading the labeler is pretty easy- just insert the cartridge. It figures out what’s going on and offers some intelligent presets.



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