79-wiring
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79-wiring
under hood coming out of firewall , besides the ones going to the electronic ign,-tan colored square plug 4 wires, the plug that connects to it has 3 wires coming into engine compartment. with key on, and testlight 1 is real bright-1 is real dim 3rd one flashs -noblink or flashers on-, trying to find why alt light is always on
Hotshot
Joined: Apr 2009
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From: Stanley, VA
To the OP, your second question. That sounds like the engine gauge feed harness. The three wires should be Red/green trace goes to coil, white/red trace goes to oil pressure sender, red/white trace goes to temp sender. This shouldn't have anything to do with your problem.
Also, you can go here for copies of the factory wiring diagrams http://fordification.net/tech/wiring.htm
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CORRECT!
I think he's trying to figure out why his ALT light is always on.
To the OP, your second question. That sounds like the engine gauge feed harness. The three wires should be Red/green trace goes to coil, white/red trace goes to oil pressure sender, red/white trace goes to temp sender. This shouldn't have anything to do with your problem.
Also, you can go here for copies of the factory wiring diagrams 1973-1979 Ford Truck Wiring Diagrams & Schematics - FORDification.net
To the OP, your second question. That sounds like the engine gauge feed harness. The three wires should be Red/green trace goes to coil, white/red trace goes to oil pressure sender, red/white trace goes to temp sender. This shouldn't have anything to do with your problem.
Also, you can go here for copies of the factory wiring diagrams 1973-1979 Ford Truck Wiring Diagrams & Schematics - FORDification.net
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MSEE
Joined: Apr 2004
Posts: 10,386
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From: Austin, TX
The sending unit wire that's flashing is likely the one that went to the temperature gauge; it's flashing because you're seeing the output of the ICVR, which is a switching regulator.
As far as the ALT light being on, remove the connector running to the regulator. The terminal that goes to the 'A' terminal of the regulator should have 12 volts at all times. The terminal that goes to the 'I' terminal of the regulator should have 12 volts with the key in RUN. Report your results.
As far as the ALT light being on, remove the connector running to the regulator. The terminal that goes to the 'A' terminal of the regulator should have 12 volts at all times. The terminal that goes to the 'I' terminal of the regulator should have 12 volts with the key in RUN. Report your results.
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The sending unit wire that's flashing is likely the one that went to the temperature gauge; it's flashing because you're seeing the output of the ICVR, which is a switching regulator.
As far as the ALT light being on, remove the connector running to the regulator. The terminal that goes to the 'A' terminal of the regulator should have 12 volts at all times. The terminal that goes to the 'I' terminal of the regulator should have 12 volts with the key in RUN. Report your results.
As far as the ALT light being on, remove the connector running to the regulator. The terminal that goes to the 'A' terminal of the regulator should have 12 volts at all times. The terminal that goes to the 'I' terminal of the regulator should have 12 volts with the key in RUN. Report your results.
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A termina with key off = 12.42v A terminal with key on = 12.15v I terminal with key off = 0v I terminal with key on = 11.40v battery with key off= 12.42v battery with key on = 12.21v
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when i put all that info in it looked identical to the way you have it,when i hit submit reply it went into sentences, maybe i should get better on the computer before i ask any more questions
MSEE
Joined: Apr 2004
Posts: 10,386
Likes: 35
From: Austin, TX
The next thing is to make sure that you have continuity between the alternator output and the battery, in order to make sure the fusible link is not blown. The safest way to do this is to disconnect the negative battery cable, then measure the resistance (ohms) between the alternator output stud and the battery side of the starter solenoid. The resistance should be no more than the resistance of your meter leads.
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I read you loud and clear; thanks for the information. This tells us that power is getting applied to the voltage regulator properly.
The next thing is to make sure that you have continuity between the alternator output and the battery, in order to make sure the fusible link is not blown. The safest way to do this is to disconnect the negative battery cable, then measure the resistance (ohms) between the alternator output stud and the battery side of the starter solenoid. The resistance should be no more than the resistance of your meter leads.
The next thing is to make sure that you have continuity between the alternator output and the battery, in order to make sure the fusible link is not blown. The safest way to do this is to disconnect the negative battery cable, then measure the resistance (ohms) between the alternator output stud and the battery side of the starter solenoid. The resistance should be no more than the resistance of your meter leads.