Main Chassis Harness ID guide, What are the changes between the different harnesses? Options

[JeffBowlsby]

Lets figure out what the differences are between the various 914/4 chassis harnesses. If you know of other facts or changes, please post them here!

Below is my current matrix of the known changes - details to be added/changed to this matrix in this first post as they become known.

Ain’t it the truth, the more we find out the less we know? I found 2 dozen listings in PET for accessory harnesses to the chassis harness, with part numbers and model-year applicability.

I also noticed one of these accessory harnesses for the dash instrument lights on a 1972 chassis harness I was loking at this weekend, never saw that before. Have you noticed any of these plug-in harnesses on your car? Some are obvious like the wiper delay is a discrete harness. Other like a special harness for the double horns on early and late cars…did you know that?

Some of the other things learned:

*Circuits for foglights were not integral with the chassis harness until 1973, previously the foglights were an optional separate harness.

*Circuits for double horns were only integral with the chassis harness from 1972-74, earlier and later they were an optional separate harness

*Wiper delay accessory harnesses are only applicable to 1972-76 cars. Early cars are SOL.

*Circuits for the EGR/CAT dash lights/sensors are in a separate harness for the 1975-76 cars.

See the chart below for more.