Big Blue's Transformation

[kramttocs]

Good point, Bill. I can't explain why that would work. Here's my take on what is happening.

Those values are calculated using the voltage divider formula and the resistances for the horn pad switches shown in the EVTM. But the resistances for the relays are my guestimates based on the current they pulled. And the On Voltage resistance is also a guess of what the input impedance is for the module.

As you can see, Set should be 13.6 volts but it is probably 11.9. So while the module may be turning On it won't Set.

So I'm going to redo things, hopefully this afternoon as we have errands to run this morning. And during the night it occurred to me that there was no reason to have the Bosch relay put the Ford relay in. Instead I'll just have the relays in parallel and either can honk the horn, as shown below.

Now this is interesting!

We currently have a similar setup (copied from the security thread):

(Your paint skills have nothing on mine )

This may be the exact reason I have been having sporadic speed control behavior. Really looking forward to your findings here.

[Gary Lewis]

Now this is interesting!

We currently have a similar setup (copied from the security thread):

(Your paint skills have nothing on mine )

This may be the exact reason I have been having sporadic speed control behavior. Really looking forward to your findings here.

I’d bet that has something to do with your problems. It is obvious that Ford is using a voltage divider to present different voltages to a logic circuit, and when you change out R1 in a voltage divider you are going to get different results.

Are they different enough that it won’t work? That probably depends on what relay you use. I happened to pick one with fairly high resistance and I think that’s why mine won’t work.

But I don’t know for sure that the red Taurus module works with the stock relay, so I’ve introduced two variables into the equation. I hope to take one of those out this afternoon, but with the weather forecast I doubt I’ll get to test it today. Maybe tomorrow?

[Gary Lewis]

I’d bet that has something to do with your problems. It is obvious that Ford is using a voltage divider to present different voltages to a logic circuit, and when you change out R1 in a voltage divider you are going to get different results.

Are they different enough that it won’t work? That probably depends on what relay you use. I happened to pick one with fairly high resistance and I think that’s why mine won’t work.

But I don’t know for sure that the red Taurus module works with the stock relay, so I’ve introduced two variables into the equation. I hope to take one of those out this afternoon, but with the weather forecast I doubt I’ll get to test it today. Maybe tomorrow?

Well, Bill may be right again. Still. As usual. Perhaps the Bosch relay would work?

I put the relays in parallel and both work properly, but independently. But the speed control doesn't. So, I can only assume that the Taurus module doesn't work in our trucks, or at least in my truck. I say that because everything should be back to just like it was before the relay changes with the exception of the module.

So I swapped the original module back in, but the storm got here before I had a chance to test it. Maybe tomorrow afternoon after we get back from our trip to Grove to decorate graves.

Anyway, here's the jumper and relay setup, but with the Taurus module still in. After the pic was taken I wrapped the connector and the spade terminals with electrical tape to ensure it can't short to something nor unplug.

[kramttocs]

Well, Bill may be right again. Still. As usual. Perhaps the Bosch relay would work?

I put the relays in parallel and both work properly, but independently. But the speed control doesn't. So, I can only assume that the Taurus module doesn't work in our trucks, or at least in my truck. I say that because everything should be back to just like it was before the relay changes with the exception of the module.

So I swapped the original module back in, but the storm got here before I had a chance to test it. Maybe tomorrow afternoon after we get back from our trip to Grove to decorate graves.

Anyway, here's the jumper and relay setup, but with the Taurus module still in. After the pic was taken I wrapped the connector and the spade terminals with electrical tape to ensure it can't short to something nor unplug.

Glad you got back in before the storm. Wind was rough here for a bit.

On the bright side - there is still the one clear test to perform before any head scratching.

[85lebaront2]

Well, Bill may be right again. Still. As usual. Perhaps the Bosch relay would work?

I put the relays in parallel and both work properly, but independently. But the speed control doesn't. So, I can only assume that the Taurus module doesn't work in our trucks, or at least in my truck. I say that because everything should be back to just like it was before the relay changes with the exception of the module.

So I swapped the original module back in, but the storm got here before I had a chance to test it. Maybe tomorrow afternoon after we get back from our trip to Grove to decorate graves.

Anyway, here's the jumper and relay setup, but with the Taurus module still in. After the pic was taken I wrapped the connector and the spade terminals with electrical tape to ensure it can't short to something nor unplug.

Gary, here is the 1992 cruise control wiring, note the location given for the horn relay location. Make sure that the connections for the amplifier are the same and that all wires are connected. I saw a dangling loose ring terminal, is it part of the cruise circuit? Note that it shows 3 slip rings (brushes and contacts).

[Gary Lewis]

Gary, here is the 1992 cruise control wiring, note the location given for the horn relay location. Make sure that the connections for the amplifier are the same and that all wires are connected. I saw a dangling loose ring terminal, is it part of the cruise circuit? Note that it shows 3 slip rings (brushes and contacts).

Scott - Yep, it got pretty stormy here just after I got back. Lots of lightning and wind. Was glad to have the truck put away.

And yes, there's one more test before the head scratching. Maybe will get to try it tomorrow when we get back from Grove to decorate graves. (Oddly enough, we'll drive part of the GOAT to get to the cemetery. )

Bill - The ring-tongue connector is ground for the AFR meter, and goes under one of the two mounting screws for the amplifier. And I checked all the wiring - it is in place.

But, I can't tell from your schematic or mine whether the wiring is the same between the modules. Both EVTM's show the same circuits going to them, but you probably have another page showing 8 more connections - 6 to the servo and 2 from the speed sensor. The '85 EVTM shows them on a separate page, so I assume yours does.

But neither shows the pin-out of the connectors. So I don't know that it didn't change. Yes, if I really wanted to I could find the connectors in the wiring diagrams and get the pin-outs there. But I only have the wiring diagrams for '85 and '86, not '92.

So, I hope to see what happens tomorrow when we get back. If it works with the original module/amplifier back in, I'll assume there's something different about the Taurus one and move on.

[85lebaront2]

Scott - Yep, it got pretty stormy here just after I got back. Lots of lightning and wind. Was glad to have the truck put away.

And yes, there's one more test before the head scratching. Maybe will get to try it tomorrow when we get back from Grove to decorate graves. (Oddly enough, we'll drive part of the GOAT to get to the cemetery. )

Bill - The ring-tongue connector is ground for the AFR meter, and goes under one of the two mounting screws for the amplifier. And I checked all the wiring - it is in place.

But, I can't tell from your schematic or mine whether the wiring is the same between the modules. Both EVTM's show the same circuits going to them, but you probably have another page showing 8 more connections - 6 to the servo and 2 from the speed sensor. The '85 EVTM shows them on a separate page, so I assume yours does.

But neither shows the pin-out of the connectors. So I don't know that it didn't change. Yes, if I really wanted to I could find the connectors in the wiring diagrams and get the pin-outs there. But I only have the wiring diagrams for '85 and '86, not '92.

So, I hope to see what happens tomorrow when we get back. If it works with the original module/amplifier back in, I'll assume there's something different about the Taurus one and move on.

Gary, the diagram is from AllData and I do not have another page. I did go back and look at the 1986 system in AllData and the 1994 Taurus system (I put the manuals for the Taurus in it when I traded it in). I am going to send them to you separately in an email so you can compare. Taurus information did include the connectors for the amplifier and servo.

[Gary Lewis]

Gary, the diagram is from AllData and I do not have another page. I did go back and look at the 1986 system in AllData and the 1994 Taurus system (I put the manuals for the Taurus in it when I traded it in). I am going to send them to you separately in an email so you can compare. Taurus information did include the connectors for the amplifier and servo.

Bill - Thanks, I got the diagrams and will study them.

As for testing the speed control today, I wimped out and will do it tomorrow on the way to KS. Drove 225 miles today in Blue (boy, that is SO much easier) and just got home. I'll report back tomorrow evening, I hope, as to how things worked out, meaning if the speed control and A/C works.

[Gary Lewis]

Bill - Thanks, I got the diagrams and will study them.

As for testing the speed control today, I wimped out and will do it tomorrow on the way to KS. Drove 225 miles today in Blue (boy, that is SO much easier) and just got home. I'll report back tomorrow evening, I hope, as to how things worked out, meaning if the speed control and A/C works.

The good new is that there is no bad news. We made the 235 mile round trip to Kansas today w/o incident and the speed control worked a treat. So the Taurus module doesn't work in my truck. (And I can't tell you if the Bosch relay as a replacement for the horn relay is viable.)

Plus, we got the A/C system working. My nephew had the new FS10 compressor, receiver/dryer, and orifice as well as new o-rings at the ready. He installed all of those components as well as the oil and pulled a vacuum on the system. His gauge pegged at 32" of vacuum, which is as good as he's ever seen, and it held there when he shut the valve. So he added the refrigerant and it worked perfectly. In fact, we got 40 degree air out of the right center vent, which he said is as cold as it should get.

So on the way home we rode in comfort, with the speed control taking care of the throttle and the A/C, with heat added, making the cab comfy.

[grumpin]

The good new is that there is no bad news. We made the 235 mile round trip to Kansas today w/o incident and the speed control worked a treat. So the Taurus module doesn't work in my truck. (And I can't tell you if the Bosch relay as a replacement for the horn relay is viable.)

Plus, we got the A/C system working. My nephew had the new FS10 compressor, receiver/dryer, and orifice as well as new o-rings at the ready. He installed all of those components as well as the oil and pulled a vacuum on the system. His gauge pegged at 32" of vacuum, which is as good as he's ever seen, and it held there when he shut the valve. So he added the refrigerant and it worked perfectly. In fact, we got 40 degree air out of the right center vent, which he said is as cold as it should get.

So on the way home we rode in comfort, with the speed control taking care of the throttle and the A/C, with heat added, making the cab comfy.

Sweet!