Resistance of '96 starter diode?
#1
Resistance of '96 starter diode?
Does anyone know the resistance value of a '96 starter diode?
Basically mine is gone and the van will not start without one.
Starter relay cluster contains 3 [FOAB-14B192AA as listed on relay] [FOAZ 14N089 A part number to order from Ford]
and 1 gray diode, in the frontmost slot and just plugs into two of the four slots, that looks like a big fuse.
Can someone tell me the part number and where I could get this part, my dealer said it was dicontinued or tell me:
-the resistance value
-where a manual or schematic that would list the value is
-somewhere I could find this info
Or, could some with access test diode for its resistance value
Basically mine is gone and the van will not start without one.
Starter relay cluster contains 3 [FOAB-14B192AA as listed on relay] [FOAZ 14N089 A part number to order from Ford]
and 1 gray diode, in the frontmost slot and just plugs into two of the four slots, that looks like a big fuse.
Can someone tell me the part number and where I could get this part, my dealer said it was dicontinued or tell me:
-the resistance value
-where a manual or schematic that would list the value is
-somewhere I could find this info
Or, could some with access test diode for its resistance value
#2
Pseudonym
Welcome to our FTE forum
I'm confused. Diodes are semiconductor devices, whose resistances depends on the forward bias voltage. Ideally it's zero in one direction and infinite in the reverse direction. There are no fixed values. Are you sure you are talking about diodes? Where exactly is this thing?
Welcome to our FTE forum
I'm confused. Diodes are semiconductor devices, whose resistances depends on the forward bias voltage. Ideally it's zero in one direction and infinite in the reverse direction. There are no fixed values. Are you sure you are talking about diodes? Where exactly is this thing?
#3
To test a diode use the diode function on your DMM to perform a voltage drop test. However on some larger diodes the voltage that a standard multimeter delivers isn't enough. So you have to test it with a load.
To test the diode with a load apply a low voltage AC current to it with a transformer and use a resistor as a dummy load to measure the output.
Check out this page for the schematic:
http://en.wikipedia.org/wiki/Rectifier
Follow the schematic for the half-wave rectifier where it says R is where you put the resistor. Now using your DMM measure the voltage from the resistor. Place your positive probe on one end and your negative on the other.
If you read a DC voltage the diode is fine. If you read an AC voltage the diode is shorted if you don't read anything the diode is open.
To test the diode with a load apply a low voltage AC current to it with a transformer and use a resistor as a dummy load to measure the output.
Check out this page for the schematic:
http://en.wikipedia.org/wiki/Rectifier
Follow the schematic for the half-wave rectifier where it says R is where you put the resistor. Now using your DMM measure the voltage from the resistor. Place your positive probe on one end and your negative on the other.
If you read a DC voltage the diode is fine. If you read an AC voltage the diode is shorted if you don't read anything the diode is open.
Last edited by krankshaft; 10-31-2007 at 12:33 AM.
#4
If what you are referring to is indeed a diode the only thing that makes sense to me is that they used it to prevent surge current from destroying the relay coil.
If this diode bit the dust you should check the relay coil its across and make sure its not fried as well.
If this diode bit the dust you should check the relay coil its across and make sure its not fried as well.
Last edited by krankshaft; 10-31-2007 at 12:30 AM.
#5
the later Aeros with high speed processor for OBDII EEC-V engine control added an additional protection diode in the relay box to reduce further the EMF kickback voltage from the PCM relay to further protect the delicate PCM electronics. wiki relay protection diodes.
I've never seen one fail in Fords. forward and reverse bias test for proper diode action. test with high impedance R testing for leakage
if your's is missing, get a 3a or 6a 25v or 50v rectifier diode at Radio Shack and put in with band cathode end on +12v side contact in relay box socket.
this diode has nothing to do with the starter relay or start circuit.
always replace the PCM relay with one that has internal diode protection also. like wearing 2 condoms
additional protection internally in the PCM with V. surge protection devices
I've never seen one fail in Fords. forward and reverse bias test for proper diode action. test with high impedance R testing for leakage
if your's is missing, get a 3a or 6a 25v or 50v rectifier diode at Radio Shack and put in with band cathode end on +12v side contact in relay box socket.
this diode has nothing to do with the starter relay or start circuit.
always replace the PCM relay with one that has internal diode protection also. like wearing 2 condoms
additional protection internally in the PCM with V. surge protection devices
Last edited by 96_4wdr; 10-31-2007 at 04:53 AM.
#6
If that's the case, the only way this diode could have affected the starter relay is if it failed in shorted mode. However, that's highly unlikely since diodes usually fail in open mode. Could it be that you put this diode in backward so the current is going through it instead of through the coil?
A simple test will be to remove the diode and see if the starter cranks. If not, the starter itself or the solenoid are more likely culprits.
A simple test will be to remove the diode and see if the starter cranks. If not, the starter itself or the solenoid are more likely culprits.
#7
RE: 96 Aerostar Diode
I was told by the dealer the item was a diode and all I needed was the value and I could find a replacement, if I remember corectly it said diode on top and had a schematic symbol of a triangle intersecting a vertical line, the plug was lt. gray about 7/8'' high x 1-1/8' wd x 3/8" thk
Located in starter relay cluster (black about 8" lg x 2" wd with 4 plugs protruding from bottom) just under drivers side hood hinge.
in the frontmost, first of four slots, two of the four slots, looks like a big fuse.
I was told by the dealer the item was a diode and all I needed was the value and I could find a replacement, if I remember corectly it said diode on top and had a schematic symbol of a triangle intersecting a vertical line, the plug was lt. gray about 7/8'' high x 1-1/8' wd x 3/8" thk
Located in starter relay cluster (black about 8" lg x 2" wd with 4 plugs protruding from bottom) just under drivers side hood hinge.
in the frontmost, first of four slots, two of the four slots, looks like a big fuse.
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#10
part # F2TF14A604AA
put in with diode cathode end marked -|<- toward brake master cylinder.
not listed in Motorcraft cross ref. and not found Ford dealer parts search.
called a PCM power relay diode
try your local pull it junke yard parts emporium, should be tons of Aeros, Ranger, Explorers etc with one
never seen one fail...someone must have a sick sense of humor to pull it out and take it.
put in with diode cathode end marked -|<- toward brake master cylinder.
not listed in Motorcraft cross ref. and not found Ford dealer parts search.
called a PCM power relay diode
try your local pull it junke yard parts emporium, should be tons of Aeros, Ranger, Explorers etc with one
never seen one fail...someone must have a sick sense of humor to pull it out and take it.
Last edited by 96_4wdr; 10-31-2007 at 02:51 PM.
#11
Originally Posted by 96_4wdr
part # F2TF14A604AA
put in with diode cathode end marked -|<- toward brake master cylinder.
not listed in Motorcraft cross ref. and not found Ford dealer parts search.
called a PCM power relay diode
put in with diode cathode end marked -|<- toward brake master cylinder.
not listed in Motorcraft cross ref. and not found Ford dealer parts search.
called a PCM power relay diode
http://www.radioshack.com/product/index.jsp?productId=2062591&cp
Much easier then going to the U Pull It for such a small part IMO.
The cathode end is the end of the diode facing the dash:
-|<-
^
Cathode
Last edited by krankshaft; 10-31-2007 at 04:22 PM.
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