[72redGTO]

On a 1972 GTO with rally gauges, where is the 3 prong TCS sending unit switch located and the 2 port black thermal purge valve located.
The original HO intake manifold( 488945) only has one threaded hole to fit one of them?
I believe the temperature sending unit( one green wire) , threads into cylinder head on passenger side from the rally gauge extension harness.

Thank you

[Kenth]

The purge valve is located on the intake next to the water outlet housing.
The TCS temperature switch is located to the rear of passenger side cylinder head between spark plugs 6 and 8.
The Rally Gauge temperature sending switch is located to the front of drivers side head between spark plugs 1 and 2.

[72redGTO]

The only problem with that is my rally gauge sending extension harness I got from M&H Wiring, which connects to the engine harness( also from M&H) sits on the passenger side.
Mine is a 4 speed car with the TCS solenoid mounted on the passenger side also.
So this rally gauge extension harness has a single green wire and a 3 prong terminal (for the TCS sending unit switch)
The single green wire is made too short to reach the driver side sending unit.
Anyone else have this problem?

[DavesGTO]

I bought my engine harness from M&H and didn’t need any extension. All the plugs you need should be on the engine harness. Only thing the engine harness didn’t come with was the rubber grommet for the idle selinoid plug, I used the one from the original harness.


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["QUICK-SILVER"]

Originally Posted by DavesGTO

I bought my engine harness from M&H and didn’t need any extension. All the plugs you need should be on the engine harness. Only thing the engine harness didn’t come with was the rubber grommet for the idle selinoid plug, I used the one from the original harness.

I highly suspect his "extension" if for the timing control and not for gauges.

Clay

[Kenth]

Found this on M&H site:
#15585 Rally Gauge Temperature Extension Harness.
1972 from engine harness to both sending units $18.00
NOTE: WITH RALLY GAUGE ONLY

[72redGTO]

Yes that is the extension harness I have from M& H(#15585),, it connects on passenger side.
When you plug in the three prong unit TCS temperature sending unit to the cylinder water jack on that passenger side,,the single green wire of that harness, will not reach water jack on driver side cylinder head single pin temperature sending unit.

[Kenth]

Since the TCS temp switch and Rally Gauge temp switch sits on either side of the water outlet on the intake for 1970-71 (all exc. 1971 455HO) the M& H #15585 will fit as intended those years.

1972 on the other hand has the Rally Gauge temp switch relocated to the front of drivers side cylinder head between #1 and #2 spark plugs and the TCS temperature switch relocated to the rear of the passenger side cylinder head between #6 and #8 sparkplugs using the M&H #15585 adapter you will need an extra extension to the Rally Gauge temp switch, like the one in my picture.

Hope this helps...

[72redGTO]

That makes sense,
Thank you very much
Do you know who sells that single green wire extension?

[Kenth]

https://www.classicindustries.com/sh...rts/?q=FB03630