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Wiring problem after engine swap.

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Old Apr 29, 2010 | 11:25 PM
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Wiring problem after engine swap.

I swaped from a 7.3 to a 6.9 and now I have 2 problems.

The lesser one is that I do not know were the wire for the tach should go.

The bigger problem is that after I had everything other than that fixed I fired it up. It started and ran great, but then when I went to shut it off it would not die. I had to pull the wire off the IP. I tried, but it will not come out of " on ". I can turn the key all the way forward and back, but it stays on.

Its like I am not even moving the key.

EDIT: Post 4,000!!!
 
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Old Apr 30, 2010 | 12:01 AM
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not sure about the truck not shutting down but do you by any chance know what vehicle the new(est) motor came from?im thinking it might not have had a tach. but im thinking you can pull parts off the 7.3 to make it work
 
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Old Apr 30, 2010 | 12:47 AM
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Thats what I was thinking. The truck and 7.3 is a 90. I put an 84 6.9 with out factory tach in.
 
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Old Apr 30, 2010 | 01:09 AM
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is there a tach sennors on the ip
 
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Old Apr 30, 2010 | 01:10 AM
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Not that I can see.
 
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Old Apr 30, 2010 | 01:12 AM
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either dose mine lol just us the old cabirted ear trick
 
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Old Apr 30, 2010 | 02:50 AM
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Here is a thread dealing with ignition wiring. Might be a good place to start.
Did you transfer all of the engine elec components, including the GP controller from the 7.3? When you shut the key off, does anything else stay on? Or just the engine?

https://www.ford-trucks.com/forums/9...on-wiring.html

Jason
 
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Old Apr 30, 2010 | 02:15 PM
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I used the 7.3s harnes and GPC.

Every thing stays on, its like I never turned the key.
Thanks for the help.
 
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Old Apr 30, 2010 | 06:18 PM
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As far as the tach sensor, you need to swap IP drive gear covers.

Remove the IP from the drive gear cover.
Now unbolt the drive gear cover and carefully remove it, leaving the IP drive gear meshed with the cam gear.

Now carefully install the IP drive gear cover that was on your old motor with the tach sensor in it.

Thinking about what could have short circuited to put power on the red/green wire to keep the engine running, but right now I am at a loss on that one.

The glow plug controller would be about the best cantidate I can think of right now since it has both battery power and ignition power on two terminals that are beside each other.
 
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Old Apr 30, 2010 | 08:44 PM
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Not 100% sure, but I think the tachometer was only an option for 85 and 86.

I wonder if you got some wires crossed on the injector pump. Could it be you swapped the high idle/timing advance with the FSS connection? The engine would likely turn itself off after about 10 minutes of running if that were the case.
 
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Old May 1, 2010 | 06:14 AM
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if you do not have any crossed wires, i bet the ignition actuator in the top of the column is broke.

on top of the column, down above the brake pedal is the ignition switch. it is held on by 2 bolts, if i remember correctly you need a 7/16 wrench. remove the switch and see if you can start and shut off the truck using a small screwdriver to work the switch. if everything works properly, the actuator is bad.

common problem point on the old body style trucks.
 
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Old May 1, 2010 | 04:43 PM
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Originally Posted by David85
I wonder if you got some wires crossed on the injector pump. Could it be you swapped the high idle/timing advance with the FSS connection? The engine would likely turn itself off after about 10 minutes of running if that were the case.
I had it running and it shut off ok. It was the second or third start that it did this.
 
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Old May 1, 2010 | 04:45 PM
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Originally Posted by Dave Sponaugle
As far as the tach sensor, you need to swap IP drive gear covers.

Remove the IP from the drive gear cover.
Now unbolt the drive gear cover and carefully remove it, leaving the IP drive gear meshed with the cam gear.

Now carefully install the IP drive gear cover that was on your old motor with the tach sensor in it.
I will do that. Thanks.
Originally Posted by Dave Sponaugle
Thinking about what could have short circuited to put power on the red/green wire to keep the engine running, but right now I am at a loss on that one.

The glow plug controller would be about the best cantidate I can think of right now since it has both battery power and ignition power on two terminals that are beside each other.
I will check that, but I think its something inside the cab. The guages and radio stayed on too.
 
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Old May 1, 2010 | 04:48 PM
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Originally Posted by tjc transport
if you do not have any crossed wires, i bet the ignition actuator in the top of the column is broke.

on top of the column, down above the brake pedal is the ignition switch. it is held on by 2 bolts, if i remember correctly you need a 7/16 wrench. remove the switch and see if you can start and shut off the truck using a small screwdriver to work the switch. if everything works properly, the actuator is bad.

common problem point on the old body style trucks.
That would cause every thing that mine is doing.
I'll check it. How much is it and how hard is it to change?
 
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Old May 1, 2010 | 05:34 PM
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If your radio stayed on too, then its definately in your ignition switch or somewhere between the switch and the key cylinder. I can't think of anytihng else that could cause all of that.
 
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