69 70 GTO engine wiring harness interchange?
 

I have a 70 GTO and the engine harness is a little rough. My brother gave me a nice 69 harness. both cars are non air manual transmission cars. Will the 69 wiring harness work on my 70? Thanks Frankie

It's been a while, but I think the engine wiring harness of the 69 and 70 are different. Fortunately the harnesses side by side would be an easy check.

70 harness
 

I don't think there is any TCS wiring on the 69 harness. Not sure if you plan on keeping this setup on your engine.

Most of the routing of the wires should be the same. Not sure but the alternator plug may be different. If his is also an original harness, may want to consider spending on a new one. If the wires are getting stiff or brittle your going to end up chasing problems (usually starter related).

You might consider selling the nice 1969 harness and put the proceeds towards the purchase of a new reproduction 1970 harness. That would help make the new harness look more attractive price wise.

I would second purchase of a new harness, just from reduced fire risk alone. The routing of starter wires is slightly different in '69 and '70, although not sure if it affects the harness. In 69 the wires run through a metal tube from front of motor back to starter above motor mount, in 1970, they did a cost reduction and just used plastic clips to secure the harness to ( I think) the oil pan gasket bolts.

Hello, Thanks for all the responses. I decided to purchase a new 70 wiring harness and already have it installed. Everything worked smoothly with it no problems. thanks again, Frankie