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watsonrx13 |
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Advanced Member ![]() ![]() ![]() ![]() Group: Members Posts: 2,735 Joined: 18-February 03 From: Plant City, FL Member No.: 312 Region Association: South East States ![]() |
Last week I swapped out the ignition tumbler then started having electrical problems. I decided this weekend I would try to tackle them. BTW, I have a '74 2.0l FI. Here's the situation:
When I turn the ignition switch on, I don't get any power to the fuse panel nor the fuel pump nor the starter. Before swapping the tumbler, everything was working fine, except the headlights wouldn't raise. They would light up, but not pop up. So, I checked the wiring diagram. Here's my interpretation of the ignition switch..... 30 - power from the battery (red) X - headlight switch (red) 15 - fuse #9 (black) & seat belt warning light (red) P - starter S - seat belt warning w/buzzer(gray/brow) 50 - seat belt warning w/buzzer (yellow) I pulled the tumbler and checked for power at ignition plug #30 - good - 12v When I turn the key, I get power to fuse #9 (12v). Also the seat belt warning light comes on (the one in the dash above the vent controls). When I close the doors, the light doesn't lite up. The seat belt buzzer sounds, but stops when the doors are closed. Looking at the diagram, it appears that there should be power to the red wire at fuse #11. I checked and nothing. I decided to place a wire directly from the battery to the #11 fuse. When I installed this wire, my headlights raised and lit up. The fog lights worked. The windshield wipers worked. The turn signals worked. Is there suppose to be a direct connection between the battery and the fuse panel? And if so, where is the conection? I think the ignition switch is bad, but I swapped out (2) others that I have in my stash, but they didn't work either. Joe has suggested that I remove the ignition switch from the tumbler and use a small screwdriver to turn the switch, which I'll perform tomorrow. Any suggestion? BTW, I don't have internet connection at the shop, so I won't be able to check until tomorrow. -- Rob |
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Spoke |
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Jerry ![]() ![]() ![]() ![]() ![]() Group: Members Posts: 6,992 Joined: 29-October 04 From: Allentown, PA Member No.: 3,031 Region Association: None ![]() ![]() |
I amended your list of items powered by contacts on the ignition switch. Changes include:
15 power the FI relay and heater relay P is power for parking lights when key is off 50 is the starter signal. 30 - power from the battery (red) X - headlight switch (red) + Fresh Air Blower 15 - fuse #9 (black) & seat belt warning light (red) + Seat belt warning system Relay & buzzer, engine ignition (coil), turns on relay for FI, power to heater relay coil P - Parking lights when key is off S - seat belt warning w/buzzer(gray/brow) 50 - seat belt warning w/buzzer (yellow), starter signal The only fuse the ignition switch turns on is 9. If you have power there you have all the power to the fuse panel that the ignition switch controls. To test your ignition switch, do this process: 1) disconnect ignition switch from car. 2) Place your voltmeter on ohms and connect one wire on 30. All measurements are made from 30 to another contact. 3) Test 15: put other wire from ohmmeter on 15. measure ohms (Inf.=infinity, ie. no connection): OFF RUN START Inf. 0 0 4) Test X: put other wire from ohmmeter on X. Measure ohms: OFF RUN START Inf. 0 Inf. 5) Test P: put other wire from ohmmeter on P. Measure ohms: OFF RUN START 0 Inf. Inf. 6) Test 50: put other wire from ohmmeter on 50. Measure ohms: OFF RUN START Inf. Inf. 0 If you measure these resistances, your ignition switch is ok. This doesn't mean your wiring is ok, just your switch is ok. If you don't have power on fuses 10-12, then this in totally independent from the ignition switch. There is a red wire on either fuses 10, 11, or 12, this wire is your problem. This wire goes directly to the battery. You must follow this wire to see that it's connections are ok. Word of Caution. Wire to #30 on the ignition switch and the wire to fuses 10-12 come directly from the battery with no fusable links. This means the amount of current available on these wires are limited by the wire itself. If you accidentally short any of these wires to ground, you most likely will hear a pop or pow and see sparks as the wire destroys itself. Be very careful when moving these wires. Disconnect battery NEG when making changes to the wiring or doing experiments. |
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