Pinpoint Tests

Fig. 34 Electric engine cooling fan wiring diagram. Type 28:

Fig. 35 Electric engine cooling fan wiring diagram. Type 29:

Refer to Figs. 34 and 35, during the following procedures.
Fan Motor Inoperative
1. Disconnect electrical connector at fan motor and connect jumper wires between negative terminal and ground and between positive terminal and B+ at motor. If motor does not run, replace motor. If motor runs, connect electrical connector at motor and proceed to step 2.
2. Disconnect electrical connector at coolant temperature switch, connect jumper wire between connector and ground on circuit 45 and turn ignition switch to `` Run.'' If motor runs, check switch ground. If ground is satisfactory, replace coolant temperature switch. If motor does not run, proceed to step 3.
3. Turn ignition switch to ``Off'' and remove jumper wire installed in step 2, then check continuity of circuit 45 from cooling fan controller (terminal 1) to coolant temperature switch. If there is no continuity, check for open in circuit 45. If there is continuity, connect jumper wire between coolant temperature switch connector to ground and proceed to step 4.
4. Connect jumper wire between B+ and circuit 687 at cooling fan controller (terminal 8) without disconnecting electrical connector from controller. If motor runs, check for open in ignition feed circuits 68 and 687. If motor does not run, remove jumper wire and proceed to step 5.
5. Disconnect electrical connector at cooling fan controller, then connect jumper wire between B+ and circuit 228 (terminal 5). If motor does not run, check for open in circuit 228. If motor runs, remove jumper wire and proceed to step 6.
6. Connect jumper wire between circuits 68 and 228 (terminals 2 and 5) at the cooling fan controller connector. If motor does not run, check for open in circuit 68. If motor runs, replace cooling fan controller and remove jumper wire from temperature switch electrical connector.