Air Cond high blow relay on big block 1972

[RalphN]

Ok.  Replacing the high blow relay.  The auto zone site says the relay for my 1972 Monte is one that has 5 lugs. The one I'm replacing has 4 lugs.  Plus there's nothing l can see to put on that 5th lug. The high speed seems the same with either. Anyone that had a big block with air, how many lugs does your relay have.  Attached are the schematic's of each. Notice the 4 lug has a flush spot where alug would be.  

Thx

[jft69z]

My 72 BB has a 4 pin relay, and a job I did earlier in the year for a 70 had a 4 pin as well.

[Chevy Dave]

The 5 terminal relay will not work with the early Monte Carlo with factory AC.  The coil can't be energized with our wiring and the high speed fan setting will not work.  If you look at the 5 terminal wiring schmetic you will see that both termonal 4 and 5 must be connected to work. You have a 3 terminal wire connector and a single one which is the ground.  I believe that the Standard Motor Products RY11 is the correct relay.  I will verify this tomorrow and post an update.

[jft69z]

The 4 seasons 35760 relay works too.

https://www.amazon.com/dp/B000C2OA34?ref_=ppx_hzsearch_conn_dt_b_fed_asin_title_1

[Chevy Dave]

I have verified that my factory AC Monte Carlo  has a Standard Motor Products RY11 relay and it works. Some 4 terminal relays like the RY8 look the same, but are wired differently internally.  [The RY8 is used on my 62 Impala with AC.]

[RalphN]

Thanks to all.