MrLexse

Since I was informed that the problem with my non working AC was a bad relay in the HVAC head I have tried to order the relay Dwayne suggested in his write-up "HVAC Compressor Relay Replacement Procedure". The Radio Shack relay 275-0218 is not available from any source I could find. There's a 12V / 10A DPDT relay (275-0043) available. but I don't know if it can be used. Anyone have any suggestions? Thanks

gazfish

Although the original relay is under rated and should ideally not be replaced with the same, it still seems to last for 30 years under normal use.

dr bob

The one I used way-back-when looks suspiciously like this one: Search "NTE Electronics R14-11D10-12 Series R14 General Purpose DC Relay, DPDT Contact Arrangement, 10 Amp, 12 VDC" on amazon and you'll be golden. I used some double-stick tape to secure it to the rear face of the HVAC controller, so it is completely hidden. Put a 5A fuse at the freeze switch to protect the PC traces in the control head, a trick proposed by Greg Brown.

MrLexse

Ordered. Thank you. Sounds like good advice to add the 5A fuse near the freeze switch as well. .

Sagres74

Different model but... any idea if this relay would work? Or is the R14 the better option? TIA
https://www.parts-express.com/NTE-R2...All%20Products

FredR

I used a POTTER & BRUNFIELD K10P-11D15-12 as recommended by Louie- I purchased 4 of them off Ebay in the States. I reckon they are the same as the Radio Shack item with a different logo on them.

Koenig-Specials 928

I need to make this mod also.
Is there a wiring diagram showing how to connect these 8 pins to the board?
Please and thanks

Koenig-Specials 928

https://rennlist.com/forums/928-foru...with-pics.html

Hey_Allen

Just as another option, Omron makes an equivalent relay as well, if they're more easily available where you are.
Omron MY2N-D2-DC12-S is nearly identical to the P-B relay mentioned earlier, though the pins are arranged differently, not having the coil terminals turned 90°.

P-B relay on Digikey: https://www.digikey.com/en/products/...1D15-12/254541
Omron relay on Digikey: https://www.digikey.com/en/products/...-DC12-S/369694