2002 Raise/Lower switch question

[JoeMacFQV]

Hi all,

Trouble-shooting my 'Birds inability to raise or lower the convertible top. I get zero pump/motor noise in either direction and zero voltage at the UP/DOWN relays, swapped the relays, no difference). I seem to have narrowed it down to the actual Raise/Lower switch but am looking for some insight from anyone that has had this issue in the past.

I have 2 different service manual sets, and both indicate the connector (C2138) is a 6-pin connector. Mine however is an 8-pin connector with 1 pin unequipped in the actual switch. I've verified the pins the associated wires go to and assuming the wiring color code is still correct I have the mapping to this 8-pin connector. Pins 1 & 4 indeed are 12v and Gnd as per the wiring color coding, so seems like the rest of the color coding might be correct.

My issue is that pin 3 (common) should not be connected to either pin 2 (lower) or pin 5 (raise) when resting. My switch has 2 & 5 shorted unless I am pressing the Raise button, which results in 2 & 5 being open, and 3 & 5 now being shorted.

Two questions then:
1) Have others seen this 8-pin configuration and is the above consistent with the color coding ?
2) Is it possible that pin 2 & 5 being shorted has somehow messed up the pump/motor with it being constantly in the lower setting (assuming this is indeed what happened). Never heard the pump/motor constantly running so seems this isn't the case, but that causes me to question if the color coding is indeed correct or not.

I've found a replacement panel with the switch and have ordered it, but am looking for any additional insights while waiting for it to get here.

Thanks everyone for the assist.

Joe


For reference, here is the connector wiring as I have determined it. Actual connector numbering (per me), lower right #1, lower left #4, upper right #5, upper left #8

Looking into the connector, using
-Pin 1 (wiring diagram), Pin 1 (actual connector) is on the lower right (Black/Green): Ground
-Pin 2 (wiring diagram), Pin 3 (actual connector), (White/Red): Lower Top

 

[JoeMacFQV]

Hi all,

Trouble-shooting my 'Birds inability to raise or lower the convertible top. I get zero pump/motor noise in either direction and zero voltage at the UP/DOWN relays, swapped the relays, no difference). I seem to have narrowed it down to the actual Raise/Lower switch but am looking for some insight from anyone that has had this issue in the past.

I have 2 different service manual sets, and both indicate the connector (C2138) is a 6-pin connector. Mine however is an 8-pin connector with 1 pin unequipped in the actual switch. I've verified the pins the associated wires go to and assuming the wiring color code is still correct I have the mapping to this 8-pin connector. Pins 1 & 4 indeed are 12v and Gnd as per the wiring color coding, so seems like the rest of the color coding might be correct.

My issue is that pin 3 (common) should not be connected to either pin 2 (lower) or pin 5 (raise) when resting. My switch has 2 & 5 shorted unless I am pressing the Raise button, which results in 2 & 5 being open, and 3 & 5 now being shorted.

Two questions then:
1) Have others seen this 8-pin configuration and is the above consistent with the color coding ?
2) Is it possible that pin 2 & 5 being shorted has somehow messed up the pump/motor with it being constantly in the lower setting (assuming this is indeed what happened). Never heard the pump/motor constantly running so seems this isn't the case, but that causes me to question if the color coding is indeed correct or not.

I've found a replacement panel with the switch and have ordered it, but am looking for any additional insights while waiting for it to get here.

Thanks everyone for the assist.

Joe


For reference, here is the connector wiring as I have determined it. Actual connector numbering (per me), lower right #1, lower left #4, upper right #5, upper left #8

Looking into the connector, using
-Pin 1 (wiring diagram), Pin 1 (actual connector) is on the lower right (Black/Green): Ground
-Pin 2 (wiring diagram), Pin 3 (actual connector), (White/Red): Lower Top

Seems not all of my wiring for the 8-pin posted. Here is that again in case it helps someone going forward.

For reference, here is the connector wiring as I have determined it. Actual connector numbering (per me), looking into the connector (not the switch), lower right #1, lower left #4, upper right #5, upper left #8

-Pin 1 (wiring diagram), Pin 1 (actual connector) is on the lower right (Black/Green): Ground
-Pin 2 (wiring diagram), Pin 3 (actual connector), (White/Red): Lower Top
-Pin 3 (wiring diagram), Pin 4 (actual connector), (Black/Blue): Ground
-Pin 4 (wiring diagram), Pin 5 (actual connector), (Blue/White): Illumination Feed
-Pin 5 (wiring diagram), Pin 7 (actual connector), (Grey/Red): Raise Top

 

[Drdipstick]

I have spent a lot of time troubleshooting raise/lower issues on my 2003. I am not familiar by memory with the exact wiring at the switch, but here is some of the troubleshooting that I did which may help you. The switch only sends a signal to the FEM/REM to activate the top. I checked my switch by removing it and checking continuity with an ohm meter. I ended up replacing the FEM with no success at solving my problem which is the top will go down but not up. Working with a local ford dealer doing the troubleshooting, we believe that the REM is at fault, but I have not replaced it yet. I built a wiring work around at the relay panel at the back. You mention that you have no voltage at the rear relays. The relays are switched by the REM and only the control power goes through the computer circuitry and not the main power. You should be able to jump the rear relay terminals to energize the top motor in either direction. If you cannot, there is an interruption in the main power source to the relays. There is a fuse in the main power circuit that should be checked. To solve my problem temporarily I built a switch assembly that independently energizes the "up" relay from the trunk area.
Hope this information helps. I may have some of the wiring diagrams from my troubleshooting that I could scan and send if you need them.

 

[JoeMacFQV]

Thanks for the reply. So I have the shop manuals, wiring diagrams, connector diagrams, etc.... problem is they are incorrect, especially for the Raise/Lower switch. You indicated you continuity tested your Raise/Lower switch, do you remember if it was a 6-pin or 7/8-pin unit ? As I indicated, there is suppose to be an open between 2 & 3 and 5 & 3 when at rest, and then a short between one pair depending on which way you press the button. In my case 2 & 3 are shorted at rest and I'm just trying to confirm that indeed this is wrong in case the documentation I have is incorrect.

Thanks

 

[Drdipstick]

I believe that mine is a 6 pin plug. What you say about 3 & 2 and 3 & 5 makes sense. I believe that you will find that pin 2 is ground and 3 and 5 are the up/down signals to the FEM. If 2&3 are shorted the top motor would have continued to run and hopefully just taken out a fuse. Follow your wiring diagram for the relays and try a 12 volt source to the pin on one that goes to the pump motor to see if it runs. If the manual is correct, and 2 & 3 are shorted, you will need a replacement switch.

 

[doug7740]

Looking at the wiring diagram below when you press the convertible top switch in one direction pin 7 from the FEM (red/gray) goes through the switch and out pin 4 (black/blue) to ground. When you press the convertible top switch in the other direction pin 3 from the FEM (white/red) goes through the switch and out pin 4 (black/blue) to ground. The FEM then sends the convertible top switch command to the REM through the computer data lines. Depending on the convertible top switch command from the FEM, the REM grounds the control side of either the raise relay or the lower relay. Voltage to both of control sides of these relays comes from fuse 21 in the battery junction box located in the luggage compartment. Voltage to the convertible top motor at the relays comes from the 175 amp mega fuse through the circuit breaker, both are located in the luggage compartment near the battery junction box.

doug7740
1955 Thunderbird Blue

 

[JoeMacFQV]

Awesome. You at least have the correct diagrams and connector size. Can you tell me the shop manual you have... I'd love to get the "correct" one.

 

[doug7740]

I have a subscription to ALLDATA that allows me to look up information for any year, make or model of vehicle.

doug7740
1955 Thunderbird Blue

 

[TopDownMadness]

Hi all,

Trouble-shooting my 'Birds inability to raise or lower the convertible top. I get zero pump/motor noise in either direction and zero voltage at the UP/DOWN relays, swapped the relays, no difference). I seem to have narrowed it down to the actual Raise/Lower switch but am looking for some insight from anyone that has had this issue in the past.

I have 2 different service manual sets, and both indicate the connector (C2138) is a 6-pin connector. Mine however is an 8-pin connector with 1 pin unequipped in the actual switch. I've verified the pins the associated wires go to and assuming the wiring color code is still correct I have the mapping to this 8-pin connector. Pins 1 & 4 indeed are 12v and Gnd as per the wiring color coding, so seems like the rest of the color coding might be correct.

My issue is that pin 3 (common) should not be connected to either pin 2 (lower) or pin 5 (raise) when resting. My switch has 2 & 5 shorted unless I am pressing the Raise button, which results in 2 & 5 being open, and 3 & 5 now being shorted.

Two questions then:
1) Have others seen this 8-pin configuration and is the above consistent with the color coding ?
2) Is it possible that pin 2 & 5 being shorted has somehow messed up the pump/motor with it being constantly in the lower setting (assuming this is indeed what happened). Never heard the pump/motor constantly running so seems this isn't the case, but that causes me to question if the color coding is indeed correct or not.

I've found a replacement panel with the switch and have ordered it, but am looking for any additional insights while waiting for it to get here.

Thanks everyone for the assist.

Joe


For reference, here is the connector wiring as I have determined it. Actual connector numbering (per me), lower right #1, lower left #4, upper right #5, upper left #8

Looking into the connector, using
-Pin 1 (wiring diagram), Pin 1 (actual connector) is on the lower right (Black/Green): Ground
-Pin 2 (wiring diagram), Pin 3 (actual connector), (White/Red): Lower Top

You're talking about switch pin-outs vs. published diagrams that are often mysterious due to revisions. Reverse engineering the color codes (and pins) should find applying a ground to the relay should raise it. But, other switch logic may determine interlock status etc.? So, it's not so easy to jumper two pins and watch her raise. I've often obsessed with wire color connectors and prints to discover they're flat wrong. Colors and harness taps change along the route and production. I've used a 'tone-tool' that sends a warbling tone across the conductor that you hear beeping on the other end with a hand-held probe. The blue wire coming off the fuse may tone-out as yellow/black at the device. You indeed metered out the switch and see no dead spots so my best tip is wait for the switch an see. Tricky stuff here.

 

[TopDownMadness]

Interesting, blew the diagram up and the switch is routed to a logic board in the A-pillar that hands off to the alarm module which then issues ground to the up/down relays. Should the switch be moved up/down there should be grounds from the alarm output pins 3 and 4. No grounds with a new switch points to the alarm device output or something back to the pillar board? They certainly made it easy. Yikes!

 

[Frankie the Fink]

All of the systems on the retro birds are convuluted most all of the controls are just signalling devices to computers that then decide what to do and take action. Like the gauge light dimming thumbwheel, it has no direct connection to any bulbs.

 

[JoeMacFQV]

Indeed... for the top, the Raise/Lower switch simply provides a ground to the FEM. The FEM in turn feeds the REM via the on-board protocol, when then issues the DC control signals to the Up or Down relay that's in the trunk. Quite convoluted. The idea is though that the auto window dropping when raising the top, the auto disable of raising the convertible top IF the hardtop is installed, and other items require intelligence in order to pull off. That I get, I just wish the FEM and REM units (the "brains") were more reliable. I've already had to replace the FEM for a few hundred dollars, I'm not likely gonna do the same for the REM... which I suspect is actually the culprit in my case.

Turns out though, at least if the schematics are correct, you should be able to adapt the Raise/Lower switch that is already sending a Ground via separate output lines/wires... to send this same ground to the Raise/Lower relays and by-pass all the smarts. When I get this tried out (and assuming it works), I'll post the solution here.

 

[TopDownMadness]

Nice, thinking "outside the box" or should that be - outside the logic module? Had another look at the blurry diagram. Do you know what interlock switch or switches detect hardtop presence? Or where they may be located? I can't find it documented but think a toggled input may interrupt the operation if it thinks the top is mounted? The schematic shows the REM in the path and it may not output the grounds? Looks like it gets a CANBUS input from the FEM. Can't see anything looking like a top on/off input to it. The FEM-n-REM may be fine but some aux input is open? The problem is, this in common to both up and down like a single interlock. Metering and jumpers will tell more.

 

[doug7740]

First off, sorry for the "blurry diagram" but I was out of town and away from my computer. I thought that at least I could send you that "blurry diagram" instead of making you wait until I got home last night. Attached is a clear diagram.

The hardtop sense circuit which tells the REM that the hardtop is installed is part of the heated rear window system. The REM knows if the hardtop is installed by checking to see if the heated rear window circuit is grounded.

doug7740
1955 Thunderbird Blue

 

[doug7740]

Turns out though, at least if the schematics are correct, you should be able to adapt the Raise/Lower switch that is already sending a Ground via separate output lines/wires... to send this same ground to the Raise/Lower relays and by-pass all the smarts. When I get this tried out (and assuming it works), I'll post the solution here.

Instead of trying to by-pass the system, wouldn't it be easier to check for faults using a scan tool?

Fault B2481, in the FEM, would indicate a convertible top up/down switch fault.
Fault B2576, in the REM, would indicate a hardtop sense input circuit fault.

doug7740
1955 Thunderbird Blue

 

[JoeMacFQV]

Indeed, if the system reported any faults… it doesn’t. Perhaps different scan tools have different capabilities, but I received no faults associated with the top. Thanks for the suggythough, I will try with 2 other scan tools just in case

 

[doug7740]

If one of your scan tools can read the data stream in the FEM or the REM, you will be able to see the convertible up/down switch operation in the FEM and the hardtop sensing switch condition in the REM.

doug7740
1955 Thunderbird Blue

 

[TopDownMadness]

Sorry about the 'blurry' comment, I had read and said 'Alarm' module where the actual word was REAR mod. I was correcting the wrong terms I had written before. The scan code would be great to verify the box talk. Found this PDF on FEM's for Thunderbirds but seems off with moving pedals? It never mentions the hardtop condition via the defrost circuit connector. Clever detect method that is. Seems with the top off, the connection is open with no resistance from the defroster load. Likely it's in a clear status to run as no switching (that could fail) is involved. Thinking the go, no-go is at the REM?

"The FEM controls the RH exterior mirrors, the power adjustable pedals, both interior and
exterior lighting active anti-theft functions, and the brake shift interlock"...

That seems like the top up/down condition may not be a FEM task but may pass switch position data to the REM? Thinking the REM handles the complete up/down tasks but needs the data input to operate? Strange they don't mention the FEM seeing the up/down switch positions. Not seeing much on REMS. Check your B+ voltage (batt) at the fuse to the REM. They document things get weird below 10 volts. Pretty sure you checked for power to the relays at the 5A fuse 21?

 

[doug7740]

With the transmission in PARK, the powertrain control module (PCM) determines the PARK position from the digital transmission range (TR) sensor input. The PCM sends a message over the standard corporate protocol (SCP) communication link to the front electronic module (FEM). The FEM then allows operation of the convertible top. The convertible top switch supplies a ground signal to the FEM. The FEM sends the signal to the rear electronics module (REM). The REM grounds the appropriate relay to raise or lower the convertible top. When the raise or lower relay is operating, the other relay remains in its normal state supplying the motor/pump ground.

The attached convertible testing document that I was going to send you from the two fault codes that I mentioned was already on this web site.

doug7740
1955 Thunderbird Blue

 

[TopDownMadness]

Nice troubleshooting flowchart and explanation. Looks like the "workshop manual" is a must have. They refer a "WDS" type code reader from the day. Thinking there's a hand-held equivalent to be had. (Probably $500 like the %$^& manual) but, maybe not? Pretty sure my $200, 5 year old reader wouldn't catch codes listed above. Posted this question, code-reader models suggestions, to Bob's Facebook site. My son has a newer Snap-On but was crazy expensive.

If the veritable "wall" is hit... as a pirate, and after checking the control switch contacts/current rating, I still see tapping the two switch ground outputs and sending a two conductor cable to the trunk. The blocking diodes are perfect. I'd leave but tape-off the pair to the FEM. The grounds are routed to the always-hot relay coil points. You lose the safety goodness and is no longer moron proof, but rolls up and down with out a satellite uplink! They made the thing reliant on data commands. You could remove the "control" pair or have a double-pole, disable switch when the top is on? Could be safe in pure analog.