Digital Dash Swap?

[arco777]

Where'd you find that?

A thread on The Ranger Station, I believe.

It was also discussed in said thread that if you don't have that pin active, the strategy loaded into your PCM may have the code in there somewhere, but it would need to be activated and have the available driver (which I read as an available output channel controller) to activate DOL features. Also, it seems this is a lot easier to do on a 5.0 motor since DOL-active PCMs are easier to find for them. For a V6 your options are limited and with the type of calculations that are used for a DOL signal, it might be tricky to find that golden PCM that accurately outputs DOL and runs a 4.0L. What we'd need is someone intimately familiar with the workings of the 4.0 PCM to snoop around in there and see if it actually is capable of outputting signal, then activating it. Perhaps Henson Performance would have that ability? I don't know if a QuarterHorse or Tweecer would be able to access that level of code... I am just rambling on here of course and this is all talking about a 94 PCM. I did consider installing a 93 PCM in my Explorer (would have to be late 93) but finding one seemed to be too much trouble for me to pursue.

 

[geoph1986]

I guess I lucked out with mine. Maybe my PCM was swapped with the motor?

 

[arco777]

I guess I lucked out with mine. Maybe my PCM was swapped with the motor?

It is entirely possible, and you could have a late 93 PCM with DOL active. Which pin did you have fuel flow on, was it 34? More importantly, what is your PCM code? It would be 4 characters (like UMP1) on the main sticker. Could you check that?

 

[geoph1986]

I can't remember if it was #31 or #34. I'm leaning towards pin #34. I can't check the pcm code because it's in the X shown in post #357, which is now someplace that I don't know where it is.

 

[arco777]

I can't check the pcm code because it's in the X shown in post #357, which is now someplace that I don't know where it is.

Aw poop.

 

[geoph1986]

We are all adults here. You can say s**t. lol

 

[arco777]

We are all adults here. You can say s**t. lol

I try to keep as polite as I can - and either way, "aw poop" seemed more appropriate for my expression at realizing what you were getting at - I even looked back to post 357 to see what you were talking about.

 

[geoph1986]

"aw poop" it is then.

 

[tomtom4049]

Personally, I found no way to re-use the stock mounting/bulb strip housing. It was too deep to use the rear lights and too brittle/fragile to modify for mounting only. Those bulbs get seriously hot and they need to be a distance away from the gauge faces anyways for even lighting, and there just isn't enough depth in the Explorer housing for a light projection setup like in the Cougar.

Your posts inspired me to go this route as well, I bought a 89 Cougar LS digicluster from eBay & a "donor" mechanical cluster like my 93 Ranger currently has, only with a tach (mine lacks one). Disassembled the donor cluster and found I could use the stock digicluster's mounting/bulb strip housing. I bought special LEDs on Amazon called AGT (advanced german technology) that have 5 LEDs on each, one faces straight out while the other four are mounted radially. No "hot spots" in the display & very evenly lit. After being on over an hour they aren't even up to body temperature. You must remember LEDs are polarity sensitive unlike a plain old light bulb so they only work installed the right way. These were not damaged by reverse polarity, I just removed the bulb holders in question and rotated them 180 degrees and reinserted them as needed. I cut long slots in the back of the donor cluster for the LED holders and the electrical strip for the lamps to protrude. I mounted my LCD displays a bit higher than you did, it is tilted downward a bit for a good fit, leaving room to cut a opening for the mechanical shift indicator. I'll relocate my High Beam and Seat Belt lamp filters to the spot on my donor cluster where 4 wheel High and Low are since I don't have four wheel drive. I could also use the ALARM lamp (I don't have an alarm system) or the Air Bag lamp (93 Ranger's had no air bag). I have the cluster together and operating on a 12 v booster pack. I bought (eBay again) a selector switch for a 90 T-bird which I mounted in the dash center AC vent's blank left half (where a 4 wheel drive switch would go). Took forever to cut that out, something like 4 hours being very careful. Looks great and like it should be there. Works like a charm on the bench. I still have to tackle wiring issues like finding the C311 plug and the one on the back of the selector switch, rewiring the relocated indicator lamps and moving filter lenses around, underhood wiring and the like. I didn't change the factory green illumination filter sheet, prefering the green to match the rest of the dash, and the 99 Explorer overhead console I installed. I modded that as well with a single yellow 12 volt LED mounted between the two map lights that comes on with the dash lights at night. I took this idea from my Jaguar X-Type which has one in a similar location. It nicely gives a soft amber lighting for the drink holders, storage bin, and between the seats that was totally in the dark before so you had to fumble around for things. Not a fun thing to have your attention diverted at night looking for something. Still have to figure out where to mount the circuit board that drives the LCD board. I'll post pictures later. I thank you for your ingenuity and inspiration a whole lot! (I've worked in component-level electronics repair for about 35 years so I have no fear.)

 

[tomtom4049]

It is entirely possible, and you could have a late 93 PCM with DOL active. Which pin did you have fuel flow on, was it 34? More importantly, what is your PCM code? It would be 4 characters (like UMP1) on the main sticker. Could you check that?

According to my diagrams pin # 34 is the correct one for Fuel flow on the 94. The 95 Explorer was on a different pin I believe.

 

[NICE59FORDF100]

Tomtom, I believe pics are in order

 

[geoph1986]

tomtom4049;

I too believe that pics are in order. Please show us!!!

I made all of my connections to the stock flexi-circuit of the Explorer. This way I was able to switch back to the stock cluster if I ever had too (which I did). I also made a separate harness for the additional wires that have no place on the flexi-circuit. That all worked well.

My problem was that I was pretty well set on using ccfl bulbs because I couldn't find a backlight that would provide even distribution. My test pics are lit with only one bulb running down the center of the housing. The final product used 2 bulbs (1 top & 1 bottom) with a piece of reflective plastic (from a laptop screen) bent concave inside the housing. If I hadn't bent the frame of the Explorer, I would have figured out a way to mount the bulbs more securely.

Again, show us some pics!

 

[tomtom4049]

Interface Module between DigiCluster & Chime Module

Here are 5 pictures of my cluster and the select switch, the LEDs I used, and the Chime-Kill switch I plan on using.

https://picasaweb.google.com/112158110244487859513/Desktop#5778390159347362210

https://picasaweb.google.com/112158110244487859513/Desktop#5778388968174670850

https://picasaweb.google.com/112158110244487859513/Desktop#5778389454356633810

https://picasaweb.google.com/112158110244487859513/Desktop#5778389255368432626

https://picasaweb.google.com/112158110244487859513/Desktop#5778389643378236514

To power the digicluster the following connections must be made (I struggled with this just a bit and don't want anybody else to do the same).

On the 20 pin connector:
Pins 2 & 8 must be grounded (12 v negative)
Pins 7, 9, & 13 must see 12 v positive.

If you unplugged the blue in-line header there is a small dot on it that corresponds to pin 1. If you accidently plug this in reversed it won't damage anything. It will light up for a moment and turn right back off. (If reversed you will see an "underscore" in the digits for MPH while it is briefly lit).

I want to use the cluster's Tone output for alerts as well. My 93 Ranger has no GEM module, only a Chime Module. I haven't probed the digicluster to find out what voltage is send out just yet, so I may have to alter my strategy a bit. My plan is to take the "headlight on" while the door is open signal wire going to the Chime Module and cut it. Then I will insert a General Purpose Diode NTE 156 in-line where I cut the wire. This will introduce a one-way-valve so the lights/door open signal can continue to pass through the diode and make it to the Chime Module as before. A second diode will be connected from the digicluster's Tone connection and meet up with the first diode on the Chime Module side of it. This gives both the tone output and the lights/door open signals a path to the Chime Module but the diodes prevent one system from "backfeeding" its signal into the other.

I'm sure the lights/door open signal is 12 v positive but the Tone output may not be. It could be only 5 volts. If that is the case I'll use a small relay with a 5 volt coil for handeling the Tone signal, and the relay contacts will trigger the Chime Module. Again I'll employ the two diodes to keep the two systems from seeing one another's signal. I imagine a low-fuel condition will trigger the Tone output so I need to simulate a sending unit's low resistance/low fuel level condition, 8 -12 ohms at empty & not a dead short to ground.

As an anti-insanity feature I have a momentary push button switch mounted on the left side of the dash beneath the headlight switch to interrupt the Tone output after one is issued. I wouldn't want to drive several miles with the chime continually going off. The schematic diagram for this now that I've finalized the design, built, debugged, and installed it

INTERFACE MODULE: Description of the three operating modes

MODE 1: Everything is peachy

This represents normal operation with engine running and adequate fuel in the tank.

The DigiCluster Tone Output is sending + 12vdc to a common (moving contact) on one set of Relay 2 contacts that are at rest, connecting with a Normally Closed contact that in turn is connected to Relay 1 coil for grounding. Since both coil connections have +12 vdc on them, there is no current through that coil. Relay 1 is inactive.

MODE 2: Time to refuel

This represents a DigiCluster-triggered Low Fuel Alert Chime due to a low fuel level in the tank. The DigiCluster Tone Output is now providing a ground which Relay 1 needs for its coil to operate as it is always getting +12vdc on the other side in RUN. Relay 1 closes its contacts which sends +12vdc through Diode D1 which has been connected to Pin 2 of the Chime Module, triggering it into operation (in the same manner as opening the driver’s door while underway would except without the dome light coming on, Diode D2 blocks that). So here we are cruising along with almost no fuel, the fuel pump icon is blinking and the Chime Alert is fulfilling it’s purpose in life. Silencing the Chime Alert in covered by the next mode of operation.

MODE 3: Silence is golden

This represents the third and final operating mode, a graceful way to quiet the Chime.
That function is handled by Relay 2. Pressing a momentary contact push button (dash mounted) sends +12vdc to one side of Relay 2’s coil (the other is always grounded). A special twist with this relay is that one set of it’s Normally Open contacts are connected across the push button switch so when Relay 2 is activated those contacts keep +12vdc being fed to it’s coil so it is now self-energized. Another set of Relay 2 contacts, a Normally Closed set, are now open. Those contacts are wired as a pass through to allow the DigiCluster’s Tone Output ground to trigger Relay 1’s coil if Relay 2 is not energized. They are open at this point and effectively stops Relay 1 from operating. The fuel pump icon is still blinking and the DigiCluster is still providing a ground but that ground isn’t going anywhere. This mode continues until you turn off the ignition and that returns Relay 2 back to Mode 1, off. If you make a stop and forget you still need fuel, you will be politely reminded again by the Chime Alert and the blinking fuel pump icon. You simply silence the reminder by again pressing the Alert Cancel push button. Once you refuel you will not be bothered by the alert again until it is once again time to visit the pumps.

Relay 1 off, Relay 2 off = No Alert
Relay 1 on & Relay 2 off = Low Fuel Chime Alert will sound
Relay 1 off & Relay 2 on = Low Fuel Chime Alert Canceled until ignition is
off
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INTERFACE MODULE CIRCUITRY DIAGRAM:

Here is the link to the jpeg: https://picasaweb.google.com/112158110244487859513/Desktop#5789658431013455538

 

[geoph1986]

That looks great. Without wanting to use the factory harness, there is absolutely tons of room for the lite bar. Keep us posted!

 

[tomtom4049]

Thanks for the kudos Geoph1986. One correction to my post, the signal to the Chime Module comes from the left-hand door jamb switch rather than from the headlight switch as I previously indicated. Goes into the Chime Module via a Red W/Pink Stripe wire on a 93 Ranger.

The cover over the LCD panels in my display is some sort of black flexible fairly thick plastic my brother got from somewhere. He's now deceased so I can't ask. I cut it with an Exacto knife & rubber cemented the black foam light-blocking gasket that was in the Cougar cluster onto the back of it.

I'm still uncertain about the Ignition Suppression Resistor (22K ohms) used on the Cougar in-line with the Tachometer wire, or if I will add the tach wire to my PCM. The cluster may not like the PCM tach input. I'm also uncertain as to the coolant temp sensor being the right one or not, will have to probe mine for resistance values and compare. Rangers seem to have 2. One for the PCM and one for the gauge. One is a 2-wire the other a 1-wire. May have to change the 1-wire out for the correct 2-wire unit.

Additionally, I'm not sure what to do with the 6/8 cylinder connection on the digicluster. I have a chart that only indicates Pin 10 (92+), the same it indicates for Pin 18 English Metric Output (92+). Hmmm... Curiouser & curiouser.

I have the pinout for the select switch is anyone needs that.

 

[NICE59FORDF100]

My solution for the chine output is this: get a chime module from the cougar or a early 90's town car and replace your explorer/ranger chime module with it. The chime request is a momentary ground input to the chime. Using a town car chime module (like I will be doing) will still have all the same inputs as the explorer one (key in ignition, door ajar, and headlights) with the addition of the chime request circuit

 

[tomtom4049]

Another chime solution...

My solution for the chine output is this: get a chime module from the cougar or a early 90's town car and replace your explorer/ranger chime module with it. The chime request is a momentary ground input to the chime. Using a town car chime module (like I will be doing) will still have all the same inputs as the explorer one (key in ignition, door ajar, and headlights) with the addition of the chime request circuit

----------------------------------------------------------------------------
Thanks for the idea. I cam up with a slightly different mod to silence the chime.

I'll use a DPDT 12 volt Relay and a momentary contact push button. Normally the relay will stay non-energized and a Normally Closed set of contacts will allow the ground from the Tone Output to pass into my existing Chime Module via a diode. Once the Tone Output is triggered I will press the Alert Cancel push button. That will send + 12v to the relay coil making it energize, releasing the NC contact (stopping the chime), and close the Normally Open contacts that will be wired across the Alert Cancel button so the relay will "hold itself energized" until I switch the ignition off. This way I can't forget to flip a On/Off switch back On after I fill up. If I make a stop before getting more gas it will remind me again when I start up. Very cheap to do. One push button, some wiring and a relay. Pretty simple. I've drawn the schematic at work, with AppleWorks, can paste it into WordPad, let me know if anyone wants it.

Anybody know where I can get a 20 pin female plug for the cluster? I've looked and looked.

Also to address swapping back to the original mechanical cluster if need be, I plan on skinning back the wires just before the factory plug and soldering my wiring at those points and taping them up or using heat shrink. The factory plugs will stay put. May use custom male/female interconnects for my stuff. I do this with aftermarket car stereos as well.

 

[tomtom4049]

Alternative solution...

My solution for the chine output is this: get a chime module from the cougar or a early 90's town car and replace your explorer/ranger chime module with it. The chime request is a momentary ground input to the chime. Using a town car chime module (like I will be doing) will still have all the same inputs as the explorer one (key in ignition, door ajar, and headlights) with the addition of the chime request circuit

Hi Nice59FordF100,
That seems a reasonable suggestion. I couldn't locate a chime like you described so I designed an alternative solution. All parts came from Radio Shack. A small circuit board, 1 SPST & 1 DPST 12 volt mini relay, 3 general purpose diodes, & 1 square momentary push button switch. I used 2 male-female plug/sockets (WAGO 4 pin) & 1 Phoenix Contact three screw male/female plug/socket. Power to operate my interface module comes from tapping into +12 in Run & Start as well as ground at the Chime module plug. The SPST (relay 1) has one side of it's coil connected to +12V, the other coil connection goes through a diode (for blocking) and through one of Relay 2 (DPDT) normally closed contacts and from there it goes on to the DigiCluster's Tone Output. When fuel level is low, the Tone output grounds out and causes R1 to energize. R1's normally open contacts close and are wired to direct +12 source voltage through a blocking diode and into the Chime Module's "Door Open" signal connection. I cut that wire and directed the door signal into my interface through another blocking diode who's other end goes back out to the Chime Module Door Open input. Once the Digicluster initiates a low fuel chime, I have a way to silence it. One set of Relay 2's normally open contacts are wired across the push button switch (mounted under the head light pull switch) so when I press the cancel button it energizes Relay 2. The contacts close and keeps +12v flowing to it's coil (it is now self-energized) and stays on. Relay 2 being activated opens (through a set of normally closed contacts) Relay 1's coil circuit turning Relay 1 off. This silences the chime alert until such time as I turn the ignition off. Then the interface resets itself so if I have not taken on more fuel, the low fuel alert is again issued next time I turn the ignition on. I integrated it into the vehicle wiring this evening and it works like a champ. With the key on, if I ground the Tone Output wire the chime goes off. When I press the Chime Alert Cancel button, the chime ceases. I decided against a simple on/off switch to silence the chime alert, afraid I'd forget to switch it back on. This is now handled automatically by default. This takes care of "Phase 5". Now I build the custom wiring harness for the DigiCluster, install it & mod the coolant temp sensor (Phase 6), then remove the mechanical cluster and mount the DigiCluster (Phase 7). Then I'll be done. (FYI, my blocking diodes prevent the door open signal backfeeding into the DigiCluster Tone Output, and prevents the Tone Output from backfeeding into the door open switch. Each has a one-way path into the Chime Module. I drew the schematic, diagram that shows the 3 operating modes in detail, board layout, and parts list. Anybody who needs it just let me know and I'll post them as jpegs through Picasa like the other pictures. I documented everything thoroughly.

 

[tomtom4049]

Connector question...

I attached progress pictures. The first one shows where I'm at with the wiring; the Merc's larger connector is currently ignored as I don't think I need it at all or the Merc's flexible circuit. Hopefully that's true, I'd like to not deal with it.

The four wires sticking up and circled in red are what I haven't found homes for (one is for VSS), and the questions asked in my last post relate to them. The buttons panel is shown and I have no idea where its wires need to go right now.

I don't plan to make the low fuel indicator or alternator warning indicators work, instead just giving them constant 12v during start/RUN to keep them turned off. On a related note, my only worry about this whole conversion is that there may be a slow drain on the system with ignition off if I have things powered that shouldn't be.

The Explorer's cluster housing has been cut up a bit and the Merc gauge assembly sits fairly low inside. Lower would be nice of course but then I'd have to relocate the flexible circuit; as is, the Explorer's flexible circuit is still in place and fully functional with the spot for the stock plugs retained. It runs the lower stock indicators only right now. I think that if I can trim the digital dash's panels, I can re-use the Explorer's black bezel to keep a clean look, and put a piece of lexan painted black in front of the gauges to protect them and cover up the empty space. I can probably retain the shift position indicator as well, as that assembly is pretty simple, but might have to lengthen the cable a little since everything will be sitting an inch or two closer to me than the stock gauge depth.

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ARCO777,
Could you look at the 20 pin plug for your digital instrument cluster (connects to the square circuit board socket) and tell me if it has numbers and a manufacturer on it somewhere?

Thanks!

 

[REMIRED55]

Really inspired to do this

Im extremely inspired to do this, however i have no knowledge or experience when it come to electronics, would it be possible to buy one of these from you guys?