See attached image for ETA datecode decoding. This was in the Wiki but most all of the
Wiki images are broken. The original ETA can last for 25+ years and 100's of thousands of miles or km's, if the wiring is undisturbed. ETA will not cause power drain, btw, it will cause limp mode and codes on the E-GAS and ASR modules. Since the ETA wiring has to be disconnected and moved all over while replacing the other 2 harnesses, if it is original and working fine now, it may be dead when you reconnect it. Moving the wires around can kill the fragile insulation. If you already have a late datecode (96-up, later the better) it may be fine.
You can also check the datecodes on both harnesses. If you are seeing insulation cracking and flaking off they are definitely old/original, but the datecode will confirm it. See attached photo, you need to look at the FD (manufacturing) date, not ZD (design).
Finally... the wiring harnesses are not always "in stock". They are sometimes built on demand when an order is placed. No need to freak out if there is zero stock, as long as it's not coded NLA, which hasn't been an issue thus far.
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