>One problem I have now (& before) is that the starter won't engage. I checked for 12 volts at the #30 terminal on the relay: it's OK. Checked for 12 volts at the relay, when turning the key to "start": that's OK too and you can hear the relay click. I guess next step is to see if the starter will engage by using a remote switch at the yellow + battery connection at the starter. Any other ideas?

Starter engagement is triggered by:

Ignition switch turned to start position energizes yellow wire on terminal 50.
Yellow wire energizes coil of starter relay (Relay V on the '93). If terminal 85 of relay is grounded thru the starter safety switch on the transmission, the relay will operate.
Starter Relay connects constant-hot terminal 30 to load terminal 87.
Terminal 87 energizes (among other things) yellow wire in Plug terminal C12.
Yellow wire energizes starter solenoid, which energizes starter.

To test:
Ensure that starting is safe. Remove Relay V. Touch a jumper from terminal 30 to terminal 87 in the socket. If starter operates, wiring to starter solenoid, solenoid and starter are probably OK.

If starter does not operate, put voltmeter from large terminal on solenoid to ground. There should be battery voltage - 12 to 12.6 vdc. If not check battery and cables. Touch jumper from 30 to 87 in Relay V socket. If voltage drops, battery or cables may be bad. If voltage does not drop, put voltmeter from starter body to good chassis connection. There should be zero vdc. Touch jumper between 30 and 87 in Relay V socket. If there is any voltage, clean or replace the ground cable going from the right side of the engine to the chassis.

If the solenoid clacks sharply when the jumper is touched from 30 to 87 in Relay V, but the starter does not operate, check starter solenoid and starter.

If the starter operates when the jumper is touched from 30 to 87 in Relay V socket, but not when the Relay is installed and the ignition switch is turned tot he start position. connect a voltmeter from terminal 86 in the socket to a good ground. Turn the ignition key to the start position - there should be 12 vdc on terminal 86. If there is, move the voltmeter ground connection to terminal 85 in the socket. Turn the ignition key to the start position. If there is 12 vdc between terminal 85 and terminal 86,
temporarily swap the fog light relay (Relay VIII) into Relay V, and try the starter. If the starter works, replace the starter relay.

Wally Plumley
928 Specialists