1992 Explorer 4.0 No Spark No Fuel
Postmaster
Joined: Dec 2001
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From: UT
Your wiring diagram and my wiring diagram don't show a black/green wire going to the EEC relay, so it is hard to tell which wire that is intended to be. If it is the wire coming from the ignition switchn (shown as red/green in the wiring diagrams), then it is supposed to have 12 V. If it is the coil ground wire (shown as black/white on the wiring diagrams), then it should show 0 V. A reading of 12 V here could indicate a break in that ground wire, which would prevent the relay from closing.
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Freshman User
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Your wiring diagram and my wiring diagram don't show a black/green wire going to the EEC relay, so it is hard to tell which wire that is intended to be. If it is the wire coming from the ignition switchn (shown as red/green in the wiring diagrams), then it is supposed to have 12 V. If it is the coil ground wire (shown as black/white on the wiring diagrams), then it should show 0 V. A reading of 12 V here could indicate a break in that ground wire, which would prevent the relay from closing.
Postmaster
Joined: Dec 2001
Posts: 3,742
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From: UT
You have + 12 V at the yellow wire, which is what it should be.
You have + 12 V at the red/green wire, which is what it should be.
You show 0 V at the black/white wire, which is going to ground, so that is what it should be.
You have 0 V at the red wire, which is supposed to show +12 V when the relay is closed.
Is that right? If that is right, it looks to me like there is something wrong with the relay (or maybe the connector the relay plugs into, if you are checking these voltages outside of the connector). It looks to me like everything is in place to cause the relay to close, but the relay is not closing. I know you said you hard wired the relay to test it earlier, but I'm beginning to suspect that the relay is getting weak enough to respond to "hard wiring" but is not responding to the "in vehicle" wiring.
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To make sure I'm following what you have:
You have + 12 V at the yellow wire, which is what it should be.
You have + 12 V at the red/green wire, which is what it should be.
You show 0 V at the black/white wire, which is going to ground, so that is what it should be.
You have 0 V at the red wire, which is supposed to show +12 V when the relay is closed.
Is that right? If that is right, it looks to me like there is something wrong with the relay (or maybe the connector the relay plugs into, if you are checking these voltages outside of the connector). It looks to me like everything is in place to cause the relay to close, but the relay is not closing. I know you said you hard wired the relay to test it earlier, but I'm beginning to suspect that the relay is getting weak enough to respond to "hard wiring" but is not responding to the "in vehicle" wiring.
You have + 12 V at the yellow wire, which is what it should be.
You have + 12 V at the red/green wire, which is what it should be.
You show 0 V at the black/white wire, which is going to ground, so that is what it should be.
You have 0 V at the red wire, which is supposed to show +12 V when the relay is closed.
Is that right? If that is right, it looks to me like there is something wrong with the relay (or maybe the connector the relay plugs into, if you are checking these voltages outside of the connector). It looks to me like everything is in place to cause the relay to close, but the relay is not closing. I know you said you hard wired the relay to test it earlier, but I'm beginning to suspect that the relay is getting weak enough to respond to "hard wiring" but is not responding to the "in vehicle" wiring.
Cargo Master
Joined: Aug 2003
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From: BC Canada
Use a DVOM and measure the solenoid circuit for short/ground..... Philip
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Freshman User
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Yeah I'm pretty confident that the 3 -4 Shift Solenoid has either failed or one of the wires has disconnected from the solenoid and is grounding out against the side of the valve body or pan.
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Postmaster
Joined: Dec 2001
Posts: 3,742
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From: UT
Yeah I'm pretty confident that the 3 -4 Shift Solenoid has either failed or one of the wires has disconnected from the solenoid and is grounding out against the side of the valve body or pan.
Cargo Master
Joined: Aug 2003
Posts: 3,263
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From: BC Canada
You are only speculating unless you test.... BEFORE dropping the pan.... Philip
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How would I test the solenoid before dropping the pan? lol, I dropped the pan and the solenoid is indeed shot. I ordered a lockup , 3-4 shift solenoid kit made by Rostra Transmission that will be here tomorrow afternoon.
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