solid state controller help

[vegas39]

vegas. I have rewired a couple older trucks to the new style plugs and controller. I have both style trucks here at the house. I will get a couple pics of both tonight and explain what goes where if no one beats me to it.

I do remember the old style controller turns the wts light on backwards from the new style. I just used a relay that is switch from the new style controller to activate the wait to start (was easier for me than rewireing the light in the dash panel).

While you are at it I would recommend remote mounting the gp controller to get it off the vibrating engine and further from heat, It should live longer that way. My truck ate two when I put the turbo on till russ clued me in that I was cooking the poor things. moved it and all was good (till I shorted a gp wire and let the smoke genie out of this one)

punk

pm your number and I can walk you through it if you want.

Thanks man. I was just planning on mounting it where the old fender relay is now. I had also read somewhere else about the relay setup for the wts light.

 

[Agnem]

And because of that, I would not call it a very "robust" design. Any connection problems and the cycle time is reduced, which means a no or hard start. The best thing I did to my 89 was to wire it with a manual pushbutton. I had 3 bad glowplugs, and with the pushbutton it still started. There is no way the factory controller would have worked correctly with that many glowplugs bad, and even with all the glowplugs good, it still refused to cycle correctly sometimes. I could go out and unplug and then plug back in the glowplug connectors on each glowplug, and it would start working again for a couple of weeks. The stock controller is just too touchy on a truck with 20 year old wiring.

I understand your argument, but if the same logic applied to the rest of the truck, we would be saying things like....

The trans is not a very robust design. 1 of the gears is cracked and it doesn't shift right.

The motor is not a very good design. The motor oil is 20 years old, and it's not working very well.

What your saying is, that because it hasn't been maintained, it is a bad design. I know you don't mean it that literally, but lets face it. It's not fair to expect this stuff to last forever without YOUR intervention. The 7.3 system is a very GOOD design. But it is up to the owner to keep all connections tight and clean, replace the relay and glow plugs preventatively, and inspect the wiring and replace damaged/corroded elements.

 

[franklin2]

Well then, I would recommend everyone who uses original NOS Ford parts replace the following every 5 years or 50,000 miles;

The complete glowplug wiring harness from the solenoid to the glowplugs
All 8 glowplugs
And the controller

Also you might need to consider replacing;

Both sending units in the tanks.

The plastic pulleys on the serpentine belt system

The pot metal acutator piece in the steering column

The headlight switch and it's connector

The firewall around the clutch master cylinder

 

[punkmechanic]

Firewall can be solved with the reinforcement (which another member is working on providing for us, hopefully cheap than the stealership).

The sending units will go bad over time, ANY sending unit (mercedes to yugo)

My steering column is orignal and has yet (knock on wood) to have an issue

The only thing that goes bad in the gp harness is the connector to the glow plug, in your earlier post you eluded too (but did not actually specify) that they where loose. Helpful tip to anyone interested. The 7.3 powerstroke uses the same gp connector, go by a dealership that works on diesels and see if they have a set they are throwing away, get them for nothing and then cut the ends of and splice into yours. Works great and its cheap and or free. The glow plug controller will last longer if you check the gps once in awhile, a bad plug jacks the resistance and the controller with its very limited logic attempts to compensate, this heats the controller and kills it.

Dust to dust nothing lasts forever. that said a properly maintained item will outlast one that is not, every time. The first diesel would still fire and run if you took it out of the case and topped off the canola oil.

punk

 

[Hoss6.9]

I didn't use a relay on my conversion to activate the WTS light.... Hooked it up like I said in the article and it works just fine....

 

[Diesel JD]

I didn't hook up the blue WTS wire at all, the 6.9 is wired so that the light is on anytime the GPs have juice which is everytime the key is on. It worked great till my dash light blew out, now I just watch the cab lights and dash dim or listen for it to click off. I like having the light but am too lazy to rig one up so far. I like the SS system a lot. It improves over the 6.9 latching relay mainly in that the failure mode is safe and won't burn up your good glow plugs or damage the engine by burning the tips off when the relay sticks on. The most foolproof system would probably be a manual toggle to 12V or constant duty glow plugs but this one is pretty good out of the box.....

 

[punkmechanic]

The biggest thing to keep in mind when converting to a toggle or momentary switch is that the "zig zag" on the solid state controller is actually a step down resistor. It puts a set load on the circuit prior to the gps and this limits the amout of current and voltage a good working set of gps will get, in turn giving them a long life span. Switching from beru's with the solid state or running beru's on a toggle could cause issues.

That said, I have run plenty of beru's on a full 12v hit from a momentary and have yet to have an issue, It is outside there design though and therefore could shorten the life span of the plug.

Most german gps (i.e. bosch) are designed for 12v and take longer to heat (internal step down resistance built into the plug?) but live a long time under such conditions.

just food for thought.

punk

 

[punkmechanic]

also the "white" wire on the forward most small terminal of the solid state is the switched ground. On pre 87 trucks you could use this as the wts light activator (it would have the wts light on when the gps where getting current). I have had this backfire in two of the trucks I have converted. It caused some sort of interference and the gps didnt stay on as long as normal. Using the relay I have had no issues, but its extra parts and more work to do.

punk

 

[The Warden]

And because of that, I would not call it a very "robust" design. Any connection problems and the cycle time is reduced, which means a no or hard start. The best thing I did to my 89 was to wire it with a manual pushbutton. I had 3 bad glowplugs, and with the pushbutton it still started. There is no way the factory controller would have worked correctly with that many glowplugs bad, and even with all the glowplugs good, it still refused to cycle correctly sometimes. I could go out and unplug and then plug back in the glowplug connectors on each glowplug, and it would start working again for a couple of weeks. The stock controller is just too touchy on a truck with 20 year old wiring.

I have a couple of thoughts regarding this.

First, a push-button system isn't for everybody. If you know how to use it, it's a good system (although I would not call it perfect; I HAVE killed glow plugs with a push-button system before)...however, for some of us, the system needs to be as close to idiot-proof as possible. I'm behind the wheel of my truck 90% of the time it's on the road, but I do at times have to allow someone else to use it...and I don't want that someone to fry my glow plugs when they don't know how to start it properly. For this reason, I would only switch back to a push-button if I had constant-duty 12 volt glow plugs installed. IIRC such a thing exists, but they're VERY expensive.

Second....this is for anyone who wants to re-engineer the wiring harness to make it play more nicely with the solid-state controller. I found out the hard way that Mel's 100% correct about the controller being calibrated to the wiring. I had the smart idea of running a separate 8 gauge (I think) wire from each glow plug to the controller. I figured that that would transmit as much current as possible from the controller to the plug and would make things happy.

Well, my controller now cycles the plugs ON for a total of about 1 second, and then cycles off and won't go through another cycle unless I turn the key off and back on. I've been through it all....all connections are happy, all 8 glow plugs (new-at-the-time Wellmans) test good, and the controller worked properly in the vehicle it was removed from. The only thing I didn't try was wiring in a factory harness...I have one sitting somewhere, but I never found time to wire it in. The only thing that seems logical at this point is that the controller is sensing the different resistance and not cycling properly. For the last 4 years now, I've had to cycle my plugs using the key, and with 1 second cycles (with 10 seconds in between) for about a minute, my truck will fire, but she'll complain doing it.

Moral of the story: Re-engineering the wiring harness to the glow plugs (just the part from the controller to the plugs, mind you) is not as easy as swapping wires. I imagine it would be possible to put in a replacement wire assembly if you want, but I think, in order to make the controller function properly, you'll need to make sure that the wire resistance is IDENTICAL to the resistance of the original wiring. I don't know what the tolerance would be, but overall, I tend to think that it's more trouble than it's worth, especially if you can get a brand new harness for only $100 or so.

Just my $0.02...

 

[franklin2]

First, a push-button system isn't for everybody. If you know how to use it, it's a good system (although I would not call it perfect; I HAVE killed glow plugs with a push-button system before)...however, for some of us, the system needs to be as close to idiot-proof as possible. I'm behind the wheel of my truck 90% of the time it's on the road, but I do at times have to allow someone else to use it.

I agree, I resisted the manual system as long as I could, because like you, I have people that borrow my truck now and then. But you can only beat your head against a wall so long before you finally give up, and I am so glad I did the conversion. You can still tell with the manual system when something is not right and one or two of the plugs are not working, because the engine will start, but it will miss-fire for a few seconds till the dead cylinders start contributing. I am very conservative with my manual switch. I do not expect my truck to start on the first try. I hold the switch for around 8-10seconds, and it usually just cranks with not much happening. I then hold it again for about 5 seconds and it will usually crank and then fire. If it's really cold out, it will try to start, but then I quit and give it another 5 seconds and then it will take off.

Moral of the story: Re-engineering the wiring harness to the glow plugs (just the part from the controller to the plugs, mind you) is not as easy as swapping wires.

I have seen some posts on here where guys have been running a new heavy wire from the solenoid to the controller, but leaving the other wiring stock. It sounds good, but when they say it starts much quicker, that gives me a hint that their glowplugs are getting hotter, and I wonder if they have a shorter life because of it. I did bypass the problem plug in the wiring, but left the factory wires in place.

 

[punkmechanic]

Warden, I know that I have had a few that acted like bad plugs (short cycle time) and all the plugs tested good, but they werent beru's. I put beru's (out of my truck no less) in to test and all but one has come back to normal. Might try a set of beru's and see if that helps. If you dont want to spend the money, stop by next time Im down and I will swap mine into your's just for testing.

punk

 

[The Warden]

I have seen some posts on here where guys have been running a new heavy wire from the solenoid to the controller, but leaving the other wiring stock. It sounds good, but when they say it starts much quicker, that gives me a hint that their glowplugs are getting hotter, and I wonder if they have a shorter life because of it. I did bypass the problem plug in the wiring, but left the factory wires in place.

Re: the potential for shorter life, that's a good thought.....but, as I understand it, the solid-state controller's specifically designed to keep from heating the plugs too long, and it bases that on changing resistance....so, my guess would be that it adjusts automatically to cycle the plugs so that they're still not overheating. That's assuming that everything's in good shape, of course....and I don't have any data points to test that. It'd be interesting to hear what others have to say.

GIven that the two smaller-gauge wires feeding the controller from the batteries tend to melt the plug in the harness, I tend to think that running a single bigger wire to the controller would be a good idea. But, again, I haven't tried it...at some point in the next few months (hopefully), I'm going to be taking my truck out of service for a while, for various reasons...I hope to get the system sorted out once and for all then.

Warden, I know that I have had a few that acted like bad plugs (short cycle time) and all the plugs tested good, but they werent beru's. I put beru's (out of my truck no less) in to test and all but one has come back to normal. Might try a set of beru's and see if that helps. If you dont want to spend the money, stop by next time Im down and I will swap mine into your's just for testing.

punk

That sounds like a good idea to me! When do you think you'll be down this way next? Any chance of sticking around through a Monday? FWIW, I actually ordered a set of Beru plugs from an online retailer...the advertisement and description specifically said they were Beru ZD-9's. I was not a happy camper when I got a set of Wellman plugs instead. A few other people on here hadn't had problems with them, so I decided to give them a shot...but, that could well be part of the problem...

 

[punkmechanic]

I dont know anything about wellmans (good or bad) If they are working then keep using them. I dont have a set plan as too when I will be down, but another run is immanent. I doubt I could stay through monday, but it only takes me a little bit to switch them over and check the cycling/ on time.

punk

 

[The Warden]

I dont have a set plan as too when I will be down, but another run is immanent. I doubt I could stay through monday, but it only takes me a little bit to switch them over and check the cycling/ on time.

Makes sense to me. If you can give me a couple of weeks' warning, I can see what I can do about getting either Saturday or Sunday off. Unfortunately, it's difficult to make any personal plans (i.e. driving down to Calvin's) on a day that I'm on duty...

FWIW, I'm going to be out of town between the 15th and the 23rd of next month...

Thanks again

 

[vegas39]

Hey everyone, our modem died Friday night and I have not been able to check in until today.
I was hoping that there would have been more info added to this thread. I know a couple of guys mentioned that they would post a diagram or pic of the new style controller and what wires do what.
I will be getting a controller and glow plugs this next week and would like to get a game plan sorted out. Thanks