Vehicle speed data
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From: The dark carnival
Vehicle speed data
The vehicle speed data comes from the vehicle speed sensor and goes to the cruise control servo and to the EEC-IV and other places in some newer rigs. But, does it go through the servo then to the EEC-IV meaning that if you yank the servo (unplug electrically and leave them hanging, unhook vacuum lines and plug them, remove the servo itself and the cable from the throttle body) the computer no longer gets the data OR does it "Y" off before the servo meaning that yanking the servo will not interrupt the data from getting to the computer?
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From: Concord, NC
I can't speak for the newer trucks, but on my 87, the speed sensor signal passes through the cruise servo then goes to the ECU. However, there are identical connectors of opposite genders on the in and out wires hanging from the servo, such that you can plug in the input wire from the VSS to the output wire going to the ECU, bypassing the cruise servo. Again, this is the case on my 87, I have no idea how far beyond 87 it holds true.
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From: The dark carnival
Originally Posted by EPNCSU2006
I can't speak for the newer trucks, but on my 87, the speed sensor signal passes through the cruise servo then goes to the ECU. However, there are identical connectors of opposite genders on the in and out wires hanging from the servo, such that you can plug in the input wire from the VSS to the output wire going to the ECU, bypassing the cruise servo. Again, this is the case on my 87, I have no idea how far beyond 87 it holds true.
But, how do you know that the signal is not Y'd off thus sending a signal to the EEC and the servo?
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From: Easton,Ks
Originally Posted by eco
Mine is an 88 with an AOD.
But, how do you know that the signal is not Y'd off thus sending a signal to the EEC and the servo?
But, how do you know that the signal is not Y'd off thus sending a signal to the EEC and the servo?
The speed sensor signal does not go to the servo.
/
Last edited by subford; Jan 24, 2008 at 08:32 PM.
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From: Concord, NC
It appears what is true on my 87 does not hold for later models, according to Bill. I know for sure on my truck that there is an in and an out on the cruise servo...I've had the wiring stripped down and laid out across my living room floor.
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From: The dark carnival
Originally Posted by subford
It is Y'd off before it gets to the Speed Control Amplifier.
The speed sensor signal does not go to the servo.
The speed sensor signal does not go to the servo.
Also, did you get the recorder? Overlays?
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From: Easton,Ks
Originally Posted by eco
Exactly which applications does that diagram apply to.
It is wired the same in my 1983 manual but without the "Y" as the 1983 does not have a computer.
There is no reason for it to go to the servo anyway, just the amplifier.
The amplifier controls the servo.
Originally Posted by eco
Also, did you get the recorder? Overlays?
Last edited by subford; Jan 25, 2008 at 06:18 AM.
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From: Easton,Ks
Originally Posted by EPNCSU2006
Is the amplifier not contained in the servo unit?
The amplifier out of a 1989:
The green plug (C714) in the above diagram goes on the left and the gray plug (C717) one on the right.
/
Last edited by subford; Jan 25, 2008 at 11:41 AM.
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From: Concord, NC
Has that been the same all along, or was that an update for 88? I'll have to go back through and figure out what I unplugged back before I replaced the throttle cable and look for the amplifier you have pictured.
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From: Easton,Ks
Originally Posted by EPNCSU2006
Has that been the same all along, or was that an update for 88? I'll have to go back through and figure out what I unplugged back before I replaced the throttle cable and look for the amplifier you have pictured.
The amplifier should be located behind the I/P at the RH side of the steering column.
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From: Easton,Ks
Originally Posted by eco
Also, did you get the recorder? Overlays?
I received the following monitor overlays:
1, 3, 4, 7, 9, 10, 17, 31, 41, 45, 66, 72, 73, 74, 75 & 76.
Is there a list somewhere that tells what vehicles go with which overlay?
I have a listing for the 1, 3, 4, 73, 74, 75, & 76 but do not know what the others are for.
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From: The dark carnival
Originally Posted by subford
I got my recorder and some overlays today.
I received the following monitor overlays:
1, 3, 4, 7, 9, 10, 17, 31, 41, 45, 66, 72, 73, 74, 75 & 76.
Is there a list somewhere that tells what vehicles go with which overlay?
I have a listing for the 1, 3, 4, 73, 74, 75, & 76 but do not know what the others are for.
I received the following monitor overlays:
1, 3, 4, 7, 9, 10, 17, 31, 41, 45, 66, 72, 73, 74, 75 & 76.
Is there a list somewhere that tells what vehicles go with which overlay?
I have a listing for the 1, 3, 4, 73, 74, 75, & 76 but do not know what the others are for.
7= Many different years and models all of which use a 2.3L OHC motor
9= Taurus and sable with 3.0, mid/late 80s
10=Aerostar with 3.0, mid/late 80s
17= 5.0 SFI, SD, many different cars (not trucks) mid/late 80s
31= 89 3.0L SHO taurus + sable
41= 91-94 1.9L MA escort + merkur scorpio
45= 90 4.9L E+F series, bronco
66= 94 2.0L SFI, MA, probe
72= ???
The listing that I have consists of a bunch of stickers that were made for putting onto the plastic pages that were for storing the overlays in the manual. I am not aware that there was any other listings for them.