solid state controller help

The hardest part about explaining this is where your are going to go from old harness (86 and earlier) to new harness (87 and later). Im pretty sure the plug on fenderwell is different and will need repinned. the easiest way is to do the swap is with a wiring diagram, a test light and reuse the 86 harness.

All the new controller needs is wiring to the glow plugs (brown wiring in your harness, goes on the end of the new controller after the zig zag step down resistor), power into the relay (red wire into your existing relay that is 12v, big wire), and a signal that the key is on (according to the article that is the red with green stripe) Then decide how you want to do the wts light (relay is what i do. pin 85 blue wire on new controller (it will have a connector on it for the new harness, pin 86 ground, pin 87 wts light in old harness purple I believe, and pin 30 would also be ground. This would cause the "signal" from the controller to be "flipped" from 12v hot to ground allowing your stock light to function with the new controller.)

Hope this helps, give me a call if you need better clarification on this or that.

punk

407-403-4221

I thought someone else had already gotten you the needed pics Vegas, its dark here now but I will get one tomorrow before work if possible.

Diesel JD said:

I thought someone else had already gotten you the needed pics Vegas, its dark here now but I will get one tomorrow before work if possible.

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Didnt get any pics yet. Thanks for your help.

punkmechanic said:

The hardest part about explaining this is where your are going to go from old harness (86 and earlier) to new harness (87 and later). Im pretty sure the plug on fenderwell is different and will need repinned. the easiest way is to do the swap is with a wiring diagram, a test light and reuse the 86 harness.

All the new controller needs is wiring to the glow plugs (brown wiring in your harness, goes on the end of the new controller after the zig zag step down resistor), power into the relay (red wire into your existing relay that is 12v, big wire), and a signal that the key is on (according to the article that is the red with green stripe) Then decide how you want to do the wts light (relay is what i do. pin 85 blue wire on new controller (it will have a connector on it for the new harness, pin 86 ground, pin 87 wts light in old harness purple I believe, and pin 30 would also be ground. This would cause the "signal" from the controller to be "flipped" from 12v hot to ground allowing your stock light to function with the new controller.)

Hope this helps, give me a call if you need better clarification on this or that.

punk

407-403-4221

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The harness that I bought, didnt come with the big type of fenderwell plug.
I guess I better post a pic of what I bought, and then we can go from there.

I will see if we have one at work that I can look at and get an idea what your up against. too bad you arent closer, I would just drive over and wire it up, vegas is a bit far for me though.

punk

punkmechanic said:

I will see if we have one at work that I can look at and get an idea what your up against. too bad you arent closer, I would just drive over and wire it up, vegas is a bit far for me though.

punk

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Yeah, you are a little far! The harness that I bought, has the glow plug connectors and the big ring terminals on the end to hook up to the controller.
It also has a few seperate wires tied in that have white plastic ends that look like they would plug onto different things on the engine.

I have a turbo, so I will have to mount the new controller on the fender.

So I guess I would have to cut the ring terminals off and tie them into my two large orange wires that come from the fender relay. Correct?

Also, is there a wire on this new relay that needs to go to a temp sensor? I have heard in the past that the solid state controller worked by picking up engine heat underneath it when mounted on the engine but I cannot use that location, as mentioned earlier because of the turbo. Thanks.

It has some sort of internal temp sensor ( I think its just a simple on/off sensor set to something but I dont know)

I would think the ring terminals go on the controller. can you get a pic on here of it? If I see it I will have a better idea, I have never seen the updated harness for the pre 86 rigs, I just used the existing harness or fabbed my own from a post 87 rig.

punk

Mine is mounted on the passenger fender well and it functions normally. Hypermax did have it over the drivers valve cover, but it melted a couple before I moved it to the fender and havent had a problem since.

punk

vegas39 said:

Also, is there a wire on this new relay that needs to go to a temp sensor? I have heard in the past that the solid state controller worked by picking up engine heat underneath it when mounted on the engine but I cannot use that location, as mentioned earlier because of the turbo. Thanks.

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Not true. The original 6.9 controllers were screwed into the water jacket for this purpose, but the 7.3 GPC is completely electronic and doesn't care what the temp is. Most who have Hypermax or similar style turbo's have relocated them off and away over a valve cover via kit supplied bracketry.

A comment on the Zig Zag strip... yes, it is a resistor, in the sense that everything in the wiring harness is a resistor. However, it's purpose is not so much to resist getting power to the plugs, thus preventing their burnout. It is really just a conductor with a known resistance, and creates a voltage drop across it's length which is measured by the electronic module built into the base of the controller. This is why a properly sized harness and 8 in-spec glow plugs are critical to the proper functioning of the system. The controller consists of two parts. One monitors the overall voltage drop across the resistor, and the other monitors the system on time. When the system is actuated, The WTS illuminiates and a 100% duty cycle is applied to the GPR and cold glow plugs draw maximum current, thus producing a large voltage drop across the zig zag strip. Typically a 50% loss in voltage occurs, meaning that the glow plugs are running on close to 6 volts. As they heat, their resistance increases, current draw goes down, and the voltage loss is reduced. Once the controller detects a 1 to 2 volt drop across the zig zag, the WTS light extinguishes and a duty cycle of something 50% or less occurs, which supplies the glow plugs with an average voltage of about 6 volts, which is delivered in 10 to 11 volt bursts. This is maintained until the timing circuit cancels all GPC operation until the next power-up cycle.

punkmechanic said:

Mine is mounted on the passenger fender well and it functions normally. Hypermax did have it over the drivers valve cover, but it melted a couple before I moved it to the fender and havent had a problem since.

punk

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Just wondering, when you relocated it, was there enough wire on the lines going from the controller to the plugs to reach to the fender? Or, did you splice in a length of wire? If so, did that affect the controller's operation any?

Thanks I hope that question made sense I'm still trying to wake up

I added a little over a foot of same gauge wire to the harnass and it has worked perfectly. Before I did this I would burn up a controller every couple months (albeit used ones but non the less) After the "move" It lasted almost two years ( I just killed it with the engine swap, I had something wired wrong in the "hurried rush" to get it to fire and The controller got a spike it didnt like and let out the magic smoke genie.

punk