Need I D on these parts

[Bob Hoffmann CLC#96]

I have some Delco parts & don't know what they fit.
15-853 AC relay
15-857 AC relay

Any help appreciated.
Thanks, Bob

[Warren Rauch]

 I wasn't able to find these numbers.  I did find that numbers begining with 15 ,do not have to be air cond /heater parts,even though product line 15 is air/heater parts. They can be found all over the electrical system as well. I also found a cross reference to GM # . 15-853  can be either 9787013 or 9792815 : 15-857 is 408337  (discontinued 1990)Warren

["Cadillac Kid" Greg Surfas 15364]

Bob,
The 15-857 is an old number, replaced by 15-8173, and if this relay has 3 connectors, it is listed for 1971-73 Oldsmobiles as  a "heater blower motor relay".  I cannot find any info on the other part numbers.

Greg