Engine Harness Plug location

[helidiesel]

Good afternoon men,

I have been spending time behind the walls of this fourm for the last 3 months after i got the idi. Thanks for all the help so far. what Im looking for is the engine harness plug that is being talked about. 6 or 8 pin from what i have read. I cant find a plug. Im thinking it has been bypassed or someone hacked the 6.9 harness to the 7.3 at the time of the motor swap. im currently troubleshooting the gp controler trying to get the gp system to work for me. I just finished replacing the key cylinder, ignition switch and actuator and rod. all is working like it should and now im on to building a gp harness after that install im going to nail down my issues with the controler... click click click click....... thanks for any help with the harness plug. im currently in a diesel tech school so forgive any of my short comings. my daily driver is a cummins....lol 6.7 deleted for MPG..

Ricky

 

[franklin2]

It's usually right in front of the A/C box. Most of the wires on top of the engine cross over the pass side valve cover and head over to the pass side inner fender. It will be in that bundle of wires. Two fat yellow wires are what feed the controller for the glowplugs.

 

[icanfixall]

Welcome to the forum. If someone cut up the harness no telling where it may be. Usually its either on the drivers or passenger side fender well depending on year of truck. Really no reason to have cut up the harness because both engines use mainly the same connections. Just look at the engine for the large bundle of wires running to it. The plug is about 1 inch wide and 3 inches long.

 

[helidiesel]

Ok. My engine wiring runs to the right side fender top. Gp leads have 60a fuses installed. I did not see that on the blue print for the harness?? As I have read on here the engine harness plug is know to melt. I think this happen at some point and the plug was bypassed. Each wire coming from the engine is spliced together at the fender area. So some of this could be leading to my gp issues. All I have left to troubleshoot if the ground for the controller and the voltage checks at the controller/relay. I have the battery's at full charge waiting for this weekend!! So what years did the wiring run to the right side fender? Also maybe off topic but I'm still trying to figure out witch water temp sensor is witch..... I know there is 3 one on the right hand side of the ip (tested good for continuity engine cold, I think that is correct) is high idle, one on the left side inboard of the head (tested open, I think is bad) cold start advance timing?, one out board of the head left side is the 244* oh sh#t (tested open engine cold, I think that is correct) thanks for the help guys. I'm going to need a lot with this truck wiring. The more I look the worse it gets!!

 

[icanfixall]

You are probably correct that the factory plug melted and is now a spliced joint. When you reference the right fender well are you saying the passenger side fender well. This right or left depends on which side your looking at the engine from. This is why most here question right or left. Many use the drivers or passenger side reference. Its much more descriptive.

 

[helidiesel]

Correct. I should use passenger side. I just always view as looking fwd. thank you. So the trucks engine harness runs to the passenger side fender well top side.

 

[franklin2]

The pass side is where most of them run because that's where the power for the truck is distributed from the battery connection on the solenoid. I am not sure about those fuses, they may blow. Like was mentioned, the glowplug system draws a lot of amps. I do not know why everyone seems to have some sort of aversion to the original fusible links. They are small, and work well and never give any problems unless someone starts monkeying with the wiring, or wrenching with the batteries still connected.

I bypassed my plug on my truck also, it was melted. But the smaller wiring portion of the plug was not melted, so I left that part in there, and on the large yellow wires I crimped ring connectors and bolted those wires together. I am glad I did this when I had to move all those wires out of the way to pull the pass side valve cover to replace the gasket. Any serious engine work is probably going to require these wires to be disconnected, so keep that in mind.

 

[helidiesel]

On the fuses I'm thinking that when u ask for fusible link most of the time u get a segment of wire with a fuse in it. I also had never see fusible link wire nor had my instructor a diesel tech of 40 + years when I was researching the gp harness. And every auto store in my area other than napa had no idea what I was talking about. Even an electrical wear house said they have never heard of such a thing as 10g fusible link wire. Lol.

 

[franklin2]

Dorman makes the fusible links. You can buy something like the picture below, or you can buy the wire and cut a piece and solder it in place. Advance Auto, Oreilly, and several others carry it. It's just a undersized piece of wire with special insulation on it that doesn't catch fire when it burns out.

http://www.autopartswarehouse.com/sku/Dorman/Fusible_Link/RB60366.html

 

[helidiesel]

Dorman makes the fusible links. You can buy something like the picture below, or you can buy the wire and cut a piece and solder it in place. Advance Auto, Oreilly, and several others carry it. It's just a undersized piece of wire with special insulation on it that doesn't catch fire when it burns out.

http://www.autopartswarehouse.com/sku/Dorman/Fusible_Link/RB60366.html

This is my point exactly. Fusible links are not the same thing as fusible link wire. Two different things.

 

[OLDBULL8]

On the fuses I'm thinking that when u ask for fusible link most of the time u get a segment of wire with a fuse in it. I also had never see fusible link wire nor had my instructor a diesel tech of 40 + years when I was researching the gp harness. And every auto store in my area other than napa had no idea what I was talking about. Even an electrical wear house said they have never heard of such a thing as 10g fusible link wire. Lol.

The definition is usually wrong.

Fuselink--Is a special type wire that acts as a fuse and is spliced in series with a circuit wire, usually at/close to the power source (Battery)
Fuselink wire comes in various sizes and is color coded.
Fusible Link-- Is as you say above.

GO Here for your truck el. circuit, scroll down to Fig.16
http://www.autozone.com/autozone/re...epairGuideContent.jsp?pageId=0900c1528007c0bc

 

[helidiesel]

The definition is usually wrong.

Fuselink--Is a special type wire that acts as a fuse and is spliced in series with a circuit wire, usually at/close to the power source (Battery)
Fuselink wire comes in various sizes and is color coded.
Fusible Link-- Is as you say above.

GO Here for your truck el. circuit, scroll down to Fig.16
http://www.autozone.com/autozone/re...epairGuideContent.jsp?pageId=0900c1528007c0bc

Thank you. I needed that about 3 weeks ago.

 

[helidiesel]

So to finish the post. I finished troubleshooting the gp/engine harness today. To start I pulled all connections from the glow plug and turned the key on. I got 12.9 volts batt side of the gp relay (freshly charged) and 10.1 volts on the voltage drop ( I thing I remember that correctly) / resistor ( thin metal strip that is curvy) side of the relay and constant 9.3 volts at each gp connector. So the I stepped back and started to twist my small brain. I was thing *** the gp should be white hot and I should have no problem starting this engine. After a short thought process I then put the connectors back on the gp them selves and did the voltage test at the relay again and the results were 12.8 battery side of the relay and 2.3-3.4 volts on the other side of the relay. So I felt very strong I had located my problem with the volts being that low on the other side of the relay. So I headed to napa and replaced the relay. Started up first key turn wit no click click click... Thanks for the help men. I will need more in the future.

 

[franklin2]

The above is a very important lesson. The same thing will happen when testing lighting problems. A light bulb doesn't work, you pull the bulb, turn on the switch, and you have 12v in the socket. The bulb is good, you put it back in, it still doesn't work.

A meter does not present enough load on a circuit to properly test it if it has a bad or poor connection somewhere. For lighting problems the easiest thing to do is buy a testlight. A testlight presents enough load on a lighting circuit to be able to determine the problem. If you insist on using a meter, you HAVE TO leave the bulb connected to the circuit and somehow test the circuit with the meter while the bulb is in place.

But with starter and heavy circuits like the the glowplugs, the testlight is not even enough load, you need to do any testing and voltage measurements with the circuit active and the loads(glowplugs, starter, etc) hooked up.

Glad you got it fixed.

 

[helidiesel]

The above is a very important lesson. The same thing will happen when testing lighting problems. A light bulb doesn't work, you pull the bulb, turn on the switch, and you have 12v in the socket. The bulb is good, you put it back in, it still doesn't work.

A meter does not present enough load on a circuit to properly test it if it has a bad or poor connection somewhere. For lighting problems the easiest thing to do is buy a testlight. A testlight presents enough load on a lighting circuit to be able to determine the problem. If you insist on using a meter, you HAVE TO leave the bulb connected to the circuit and somehow test the circuit with the meter while the bulb is in place.

But with starter and heavy circuits like the the glowplugs, the testlight is not even enough load, you need to do any testing and voltage measurements with the circuit active and the loads(glowplugs, starter, etc) hooked up.

Glad you got it fixed.

Thank you very much!! Now it's on to figure out why the truck is smoking so much!! But that will be lots R and D and testing and a different post after injector pop testing and compression tests. Thank again for the help.