Handbook 652 Body Electrical Diagnosis Relay Blocks A relay block acts as a central location for relays and fuses. Although similar in appearance to a junction block, relay blocks are different because they do not have internal circuits to distribute power or ground. Relay blocks in the system circuit diagram are not color-coded , but are usually connected to a component such as a relay or a fuse, which is color-coded light blue. You will know the component is at a relay block because the component connections are indicated with an oval. Inside the oval is the R/B ID number. A letter is not used to identify the connector because the R/B does not have separate connectors.
The R/B ID appears in a cross reference list following the system circuit diagram with the page number of the R/B diagram in the Relay Location section. 80 Technical Training