as we know a relay is simply a switch that electrically understands that we want to start something and when it senses we have so indicated it then opens the full voltage/amps to the target electrically run unit. like fans, horns lights etc.
My question is has anyone found modern relays that can be used in place of the lucas r-6 on our vehicles. I am sure there are plenty of relays available and that can be used I just need to know what they are. can you help

Submitted by SE21-38504 on Tue, 01/22/2013 - 09:51

A similar size relay is a GP Sorenson AC28 available from GM dealers (same as what GM used on my 1987 GMC van). You can insert the innards of this relay into the metal shell of a Lucas 6RA relay for a factory look. I have also used Bosch relays that have an integral fuse that works well, but lacks the original appearance of the Lucas.

Bend open the ridge and remove the innards of the new relay. Saw off the plastic skirt around the outside base of the innards. Insert the new innards into the old Lucas relay shell with a seal of silicon around the inside edge and rebend the rim.

The new relay lugs extend through the bottom of the relay and avoids using rivets (which corrode) to make contact between the inside and outside as Lucas does. It will fit perfectly inside the Lucas shell which has ears for the correct attachment to the Jag's chassis.

Reconnect wiring to the terminals as follows. The terminal code numbers are in the order of Lucas=American=Euro DIN:
"normally open" relay terminals: C1=1=30 C2=2=87 W1=3=85 W2=4=86
"normally closed" relay terminals: C1=1=30 C2=5=87a W1=3=85 W2=4=86

The below schematic diagram is what I have on my '69 FHC. I think I wired the bottom relay to take current out of the ignition switch to reduce current, heaat, and melting problems. Hope this helps!