After searching high and low I finally found an engine in the price range I wanted to pay. I really wanted a 6.9 but I couldn't find on cheap enough or close enough to me. So I am going to install a 7.3 I found really close for a good price. I think there are a couple of different things I will need to change over for this repower. Is there something different I will need to do for the glow plugs? I have a push button system right now, but I wouldn't mind using the controller on the 7.3 since I have read that they are more reliable. Is there any other changes I should be aware of?

 

I forgot to add my my truck is an 86 f350.

 

I would get a 7.3 glow plug relay and have the glow plugs work automatically.

I have a push button as a back-up and only use it if and when I need to get the truck started when a glow plug burns out. My 93' will not start without glowplugs it will puff white smoke till the cows come home.

Sebastian.

 

Does the 7.3 have the engine wiring harness still on it?
There are minor differences in the wiring, easy to fix.

It should have the filter/water seperator combination already on it as well.
That is a good thing so you can ditch the stock water seperator which is bad about leaking air. A minor replumbing of the fuel lines is required to do that part.

The rest of the stuff is a straight swap of parts.

 

Yes, it does have the engine harness with it. Do you know offhand what the minor changes I will need to make?

 

The late model engine harness will not plug into the early style connector that is on the chassis.

The late model harness has battery power running to the relay that is mounted on the rear of the intake manifold. The early style has the relay mounted behind the passenger side battery.

What you will wind up doing is cutting the connectors off both the chassis harness and the engine harness.

I like my manual glow plugs on my 86.
So I put a bolt through the glow plug ring connector and the battery power ring connector where the 7.3 controller would set. Then I taped it all up real good and also taped up the red wire with the green stripe so they could not short out.

Over where the connectors were located near the dip stick I used a copper split bolt to connect the two large orange wires with a white strip (Chassis side) and the two large yellow wires ( engine side) together and taped it up real good. This gets the glow plugs working with the manual push button.

On both the engine harness and the chassis harness there is a red wire with a green stripe, this is the ignition circuit. Connect these wires together.

On both the engine harness and the chassis harness there is a white wire with a red stripe. Connect those two together. This is the oil pressure gauge wire.

On both there is a red wire with a white stripe that connect together.

On the engine side there is a white wire with a blue stripe that connects to a red wire with a black stripe on the chassis side. This is for the temp gauge.

I will check my connections again tomorrow since I did not label the function when I did mine. It was not that important since I have mechanical gauges for the engine vitals.

The glow plug circuit and the red and green stripe wire are all you really need to drive the truck if you have real gauges installed.

Also if you want to convert to the automatic glow plug late model system I can tell you how to do that.

 

Could you let me know how to convert to the late model automatic glow plug system? Thanks.

 

Also, if I do stay with the push button system, will there be a problem with voltage issues at the glow plugs? It seems like I have read somewhere that Ford has put 12 volt and 6 volt glow plugs in these trucks. I just want to make sure that this will not be a problem for me. The engine I will be installing is a 7.3 from a 1992 truck.

 

No problem at all.
I use the system I described above with the new style glow plugs in my 6.9.

To make the automatic system work you need to remove the relay for the old style system. Look at the size of the orange wires on the old relay, should be #8 wire.
Get two pieces of #8 wire long enough to go from the connector on the engine harness to the positive battery terminal and install ring terminals that will go over the battery terminal bolts.
After you splice the engine harness wires to the new wires from the battery, everything else should already be hooked up on the relay and controller.

 

I decided to try and use the existing 7.3 controller. I connected all of the wires you listed. There are still 6 wires left in the 7.3 engine connector. They are: blue, red with yellow stripe, blue with red stripe, black with blue stripe, red, and black with purple stripe. I think I have figured out 3 out of the six. The blue and blue with red stripe wires go to the fuel filter head. Those aren't necessary I don't believe. The black with purple stripe wire I think is the wait to start lamp. I traced it down to the glow plug relay. Should it be OK to hook that to the black with purple stripe wire that went to the old glow plug relay? My schematics show that that is the wire that goes to the wait to start lamp. That leaves the red, red with yellow stripe, and black with blue stripe wires. Any ideas what these go to?

 

Down one side of the connector.
Yellow - glow plug power
Red green stripe - ignition
white red stripe - oil pressure
white blue stripe - temp light
blue red stripe - fuel filter restriction light
black red stripe - wait to start light

Down the other side
Yellow - glow plug power
Blue - fuel filter heat
red white stripe - temp gauge
red yellow stripe - connector A
black blue stripe - connector A
red - connector A

By the IP is connector A
it has 4 wires in it
red yellow -
red -
black blue stripe -
black -
I had no where to plug this in
I am assuming it is for trucks with an automatic transmission for the throttle position sensor.

On the 86 truck side one side has,

Orange - glow plug power out of the relay
No Connection
Red black stripe - temp light
White red stripe - oil pressure

Other side
Orange - glow plug power out of the relay
Purple - to glow plug relay from glow plug controller
Red green stripe - ignition
Red white stripe - temp gauge

 

Well, I finally got the old truck started tonight. I didn't have much time so I didn't get it fully warmed up or anything, just started up and ran enough to get all of the air out of the system. I do have a couple of questions though. When I turned the key on I heard the glow plug relay click (I am using the controller). My wait to start light seems to be inop. About 10 seconds later it clicked again. After that click it started clicking pretty frequently, probably once a second. I couldn't tell if it stopped after the engine started because I couldn't hear it and my wts light is inop. Is this normal? I'm sure the glow plugs are working because initially I tried to start it with the controller disabled and no luck. I connected the controller and it started almost immediately. Should I ditch the controller for a push button? I would like to use the controller if possible though. Also, I have another small question. On this 7.3 there is a port on the passenger side valve cover for crankcase vent, I'm assuming. On my 6.9 there is no port. The valve cover is solid. Where is this port supposed to be connected to?

 

Sorry to hi-jack the thread, but...sorta related:

My truck ('85 F350) has been converted to a 7.3. There is a glow-plug push button on the dash. When do I use this? If I press it, the "glow-plug" light lights up on the dash.

Thanks,

D. Ocean

 

With an ATS turbo the CDR is relocated to the drivers side valve cover from the stock location behind the intake throat.

Don't know where banks relocates it to.

The turbo pedistal mounts where the CDR was on the ATS system so the oil can drain back into the engine.

Do you have a CDR on the rear of the intake throat?

 

Yes, I'm pretty sure I have a CDR valve on the rear of the intake throat, but I do not have a turbo on this engine.