Mini-ISO Relays

Uh, Relays?

The Basic Car Audio Electronics site has a very good explanation of how relays work.

Mini-ISO

30-amp Mini-ISO relay with pre-wired single and double sockets

The most commonly found aftermarket relays are Mini-ISO relays, typically referred to as "Bosch-type". There are many brands available, including Bosch, Hella, and whatever no-name brand your local Kragen stocks. To my knowledge, none of the available relays are fully sealed. The bottom panels appear solid, but there is no epoxy applied where the terminals enter the body, so ultimately there is a path for moisture. If you want a 100% sealed relay, look at these.

30-amp relays typicall come with a mounting tab. Personally, I would much prefer that the socket be mounted, and the relay itself be easily changeable.

WayTek sells the Bosch 3 334 485 008 relay socket (WayTek p/n 75280) for $0.73 each, minimum seven.

Sockets

Bosch Mini-ISO relay socket without tab p/n 3-334-485-007

Bosch Mini-ISO relay socket with tab p/n 3-334-485-008

Relay sockets make it much easier to change out a bad relay. Without a socket, you'll have to remember which wire went to which terminal pin. Relays are generally extremely reliable, but if you're trying to track down an electrical gremlin the last thing you want to do is fiddle with such a headache.

Tessco sells supposedly genuine Bosch sockets (note that their pictures do not match mine, but their part numbers do):

• $0.80 for sockets with mounting tab (p/n 465687, Bosch p/n 3-334-485-008).
• $0.45 for sockets without mounting tab (p/n 464695, Bosch p/n 3-334-485-007).

Neither of these come with the metal terminal inserts, those are sold separately (p/n 91211, Bosch p/n 42238-2/100, 100 pack, $22.25!). Alternatively, pre-wired sockets (Wireless Solutions p/n RH1) are available for $2.10, but you can't get these with a mounting tab.

Hella makes female terminals ("FEMALE DISCONNECTS with CATCH"), p/n 87272:

• $14.69 from Summit Racing

Hella also makes a relay socket with mounting tab, p/n 87122 (presumably without terminals):

• $2.39 from Summit Racing.
• $1.22 from REM Electronics.

This page shows two Bosch Mini-ISO relay sockets. Part number 3 334 485 007 (no mounting tab) and 3 334 485 008 (with mounting tab).