I'm so glad David found out about this. I've been chasing a power
drain in my RX-4 for months. I found a nut that had fallen across two
terminals on the fuse block. I thought that would solve the problem,
but it didn't.
If I didn't drive the car for 2 or 3 days the battery would be dead.
I solved the problem by putting in a yellow Optima (what a great
battery), but I knew power was still draining. I had traced it to the
alternator (late model FC) when this thread began.
I've installed that alternator (FC) in my SE and put the relay on per
this thread. Pictures and a wiring diagram are at..
http://intertron.com/ron/relay1.jpg
http://intertron.com/ron/relay2.jpg
http://intertron.com/ron/relay3.jpg
#1 This is the top of the relay I used. Normally open 30 amp relay.
I think I got it from Advance Auto Parts. Most relays have a diagram
like this on the case. If terminals 86 gets 12V and 85 is grounded
(or vice versa), power from 30 can flow through to 87 (or vice
versa). No power to 86 no power to 87.
#2 This is a picture of the relay installed. I hooked it up near
the alternator to make sure it worked. I'll be moving it to the inner
driver's fender near the AC relays. This hookup makes a great
picture. One red wire is grounded to the firewall. The other is
spliced into the Blue/black wire in plug G-10. This is a connector
between the main harness and the front AC harness. It is located in
the left (driver's), rear corner of the engine compartment. This wire
should be on all 84/85 cars. It supplies switched power to the AC
relays. This is the general spot I will be mounting the alternator
relay in the future. I chose the L terminal wire to install the
relay. It is the small white wire on the FC alternator plug, which
connects to the White/black wire in the FB harness plug. I have used
another plug that mates with the plug on the car. That's why you see
blue and black wires.
#3 This is a diagram of the connections.
Now I need to do this to my RX-4 with the FD alternator that I just
installed.
Ron Slabach
Naples, FL