I am reinstalling my injectors and I want to make certain I do not cross the primary wires with the secondary. Do both the primary wires come out of the same harness?

 

the primary are the shorter ones as the secondary wires are longer.

 

So that means that they come out of diffrent harnesses.

 

They all come from the same harness, but they're all different lengths and will naturally fall closest to the correct injector. If you have to pull on the connector to make it reach, it's the wrong one. If you're still unsure, peel back the rubber boot to expose the wires and confirm using the wire colours in the wiring diagrams.

 

OFten the light green primary color of the injector leads is faded to brown, and the stripe indicator is also faded so this doesn't always work on the older models.

But yes, if the harness is laying on the engine, they pretty much point directly to where they should go...no injector lead should cross over another one. On the turbo models, there are 2 "branches"...the front branch is for the front primary and secondary (no way to mix these up) and the rear branch is for...you guessed it...the rear injectors.

Unless you have a re-loomed harness, or a new or like-new harness, there's not really a way to mess this up. On new harnesses (and good condition used ones) the front injectors (primary and secondary) are marked with beige tape around the harness insulation near the connector.