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1st Generation 1964 1/2 - 1973 - Questions & general discussions that apply to a specific year => 1970 Mustang => Topic started by: skunk95 on May 20, 2014, 04:32:34 PM

Title: 1970 Under Dash Harness
Post by: skunk95 on May 20, 2014, 04:32:34 PM
Hi

my understanding is that the 1970 fastback had two under dash wiring harnesses. one for a tach car and one for a non tach car. Does anyone know if a San Jose built non tach car with AC and California emissions had a different harness again.

thanks

skunk95
Title: Re: 1970 Under Dash Harness
Post by: midlife on May 20, 2014, 09:59:43 PM
There were actually four underdash harnesses:
non-tach without A/C
non-tach with A/C
tach without A/C
tach with A/C

I have never run across a harness that wasn't one of these configurations.  There were a couple mid-year changes, notably in the door ajar wiring relay and various heater box wiring changes (location of break-outs from the main harness but not functionality).

All 1970's had an emissions control line to the carb (not quite an anti-backfire valve, but similar...).  I suspect California cars had different smog controls, but that was only under the hood as far as changes relative to the other states.

Just my observations of well over 150 1970 underdash harnesses.
Title: Re: 1970 Under Dash Harness
Post by: J_Speegle on May 20, 2014, 10:44:34 PM
...............I suspect California cars had different smog controls, but that was only under the hood as far as changes relative to the other states.

Other than the vapor return system I can't recall any that were not the same a the 49 state requirements
Title: Re: 1970 Under Dash Harness
Post by: skunk95 on May 21, 2014, 10:02:20 AM
thank you both for your help

skunk 95