355 Spider Convertible Top Issue

The ecu has shut down the circuit. There's a fault in the system. I assume your emergency switch it operating?

 

Unfortunately, the workshop manual's roof wiring schematic doesn't have the detail the normal wiring schematics have. You may have to use a wire tracker.

Did you have the ignition on when checking the power to the switches? The diagram shows unfused power coming from the ignition switch to the switches.

Do you have ignition power to pin 4 of both relay bases? And also to pin B20 of the ECU plug (car side) i.e. a green-white wire?

Note that if you have no ignition power, the bypass system will not work. The same relays are used.

 

Tom, if Ralph is talking about DVM voltage readings at the switches, then I can't see how the ECU can deprive the switches of volts.

Spider roof schematic

 

Yes that is why I asked if the emergency switch is working. If that is also not working then there is definatly a power or ground issue. Obviously key must be on..other thing to try is have the car running. Low voltage can cause all kinds of dumb things to happen..

 

I had a quick look at my spider and realised that a wire tracker would be almost useless. The switches' green-white (ignition lock-sourced) power wire disappears into a larger harness in the centre console tunnel.

There are no fuses shown in the workshop manual or in the owner's handbook for the switches (relay coils, solenoid valve, etc) relating to ignition power . It may get power from fuse 25 ("AC System") in the passenger footwell (this is fuse 24 on later cars). This fuse feeds dozens of things on the car (via a green-white wire coming out of the footwell relay panel on pin 2 of plug "A"). This is the only green white wire coming out of the relay panel. The wire goes to numerous splices. If there was no power here, there would be lots of problems with the car.

Basically, no voltage in a circuit is caused by either a shorted or an open circuit wire or component. Assuming fuse 24 feeds power to the roof system (and that there are no other problems with the car), there must be an open circuit somewhere.

 

Thanks for all the inputs. Problem still exists. Initially, the seats were able to be moved by the switches on the center console. Measurement os the wires to these switches are now dead. emergency override to open and close the top works. No problem. Voltage to B20 is there. Each seat switch in the console receives 5 wires. As shown on the schematic several wires are common to each such as +12V in puts and ground. Thus, I concluded there must be a distribution block somewhere and possible fuse. I will check the passenger the footwell for the fuse.

 

Frustratingly, there are no "distribution blocks" in F355 wiring. Ferrari hides splices in looms and sometimes even in connector plugs.

If that fuse is used for the roof (it's currently only speculation), it will be the power source for the motor relay coils. Since the relays are operating in emergency override mode, the fuse will be ok.

However, if you do check the fuse, if you can figure out which is the non-ignition side, it would be great if you could remove the fuse and check the continuity of the wiring between the non-ignition side of the fuse and, say, B20. This will prove that the fuse does indeed supply power to the roof system. Then I can add this detail to my wiring diagram

Control of the seats will be inactive (by system logic) until the roof is fully down (as sensed by the main actuator internal switches "S1" and "S3"). However, there should still be voltage going to the seat switches (power is hardwired to the switches).

 

I may have to confirm this on my own car. I know that the seats automatically start moving back to the normal driving position when the main roof hydraulic actuators are fully extended (i.e. roof fully down).

If power does come from fuse 24/25, it may go through the upper white connector "40142" (at the extreme front of the centre console). i.e. one of the 20 pin plugs inboard of the passenger footwell relay panel. i.e. pin 19. This pin has a green-white wire powered by the AC System fuse. However, your problem seems to be aft of this connector.

Here's a picture of the white plugs for reference:
https://www.ferrarichat.com/forum/posts/144748661/

 

I found the source. The AC fuse in the passenger bottom fuse panel feeds power to the switches. My fuse was blown.

 

Excellent... but strange. That fuse feeds dozens of other items. You didn't notice oil temperature, fuel gauge, speedo and airconditioning not working? Or were you just taking your car out of storage?

 

P.S. It also seems odd that you had power at B20. Perhaps that uses a different fuse?

 

The workshop manual shows the following items hooked up to power from the ignition lock:

Seat and roof switches
Pin B20 of the roof ECU
Secondary hydraulic soleniod "F1"
Hydraulic motor relay coils

However, the wiring is overly simplified. I did some continuity checks on my '98 spider between the AC System fuse holder and the above items. The AC System fuse in the passenger footwell on my car feeds ignition lock power to the seat/roof switches and pin "B20" on the roof controller (as per the workshop manual). However, the coils of the motor relays and the hydraulic solenoid "F1" show an 80 ohm resistance, suggesting an alternate path (and are probably not powered by that fuse).

I don't know why there are differences between my car and Ralph's car. Ralph reported that he was getting power at B20 with the AC System fuse blown.

Here's a revised wiring diagram showing the AC System fuse feeding the seat/roof switches and pin "B20" on the ECU (as per my '98 car). I've had to leave the last two items on the list unconnected.

Updated (5.2) Spider Roof Wiring Diagram

Perhaps someone has a proper wiring diagram and can fill in the details?

 

From another thread it stated the AC fuse supplies power to the seats switches and the top controller. My fuse was blown. Replacing it, the seats work, but the controller for the top does nothing. When i bought the car the top controller was not working. Purchased a new unit from Eurospares. It failed. Bought a new unit from Ferrari dealer in CT. It worked once and does not function today. Anyone else have that problem? Override does work.

 

Just to get the timeline correct:

Roof & seats not working. Fuse replaced. Seats worked, but roof didn't. Purchase a new ECU from Eurospares? It failed. What stopped working? Only the roof? Could you still move the seats with the seat switches?


Then... Purchased a second ECU from C.T. dealer. It worked once and then failed. Do the seats work with the seat switches?

By "new controllers", you mean second hand ones? I thought new ones were NLA.

 

Here is what I know about the roof operation: Power to the console switch comes from the AC fuse (10 amp). Distribution of power and grounds is accomplished by jumping wires in and out of the switches on the console ( seat and roof switches) Override of roof control has separate power from AC fuse. My expensive roof controller allows seats to move, but not the roof. My mechanic thinks the controller has to be programmed to work. No beeps from roof controller or micro switches. . Now looking to rewire the system using the override input.

 

Confirmed on my car.

Also confirmed on my car. The ignition provides power to the opening and closing relay coils (which are used by both the normal and override system), but not via the AC System fuse. Note that the override switches simply provide an alternate earth for the relay coils (Normally the roof ECU provides these earths).

Strange. So you don't even get a beep when you pull back on the roof (as part of the opening procedure)? I don't know how familiar your technician is with the roof system. Do you know if he has confirmed that switch "S12" is making contact with the frame when you push back on the roof? S12 is located in the upper rear right hand corner of the roof frame and is a common cause of roof problems. The microswitch arm gets bent. This switch is vital to roof operation.

It's odd that the roof did work for a while, but it's a good sign that your seats move (with manual input at least).

Sorry for my persistence. I just want to make sure that you don't overlook a simple/cheap solution.

(EDIT: I've updated my wiring diagram to show the AC System fuse not feeding the relays. I confirmed that they do use igniton power however)

Spider Roof Wiring Diagram (5.2)

 

I think this type controller predates the programmable type. The "Power-Packer DUC1314-11-99" ECU is only compatible with two cars (the F355 and an Opel convertible of that era). If it was programmable, I'm sure it would be compatible with a lot more cars.

The Alfa 916 Spider (95~2003) roof ECU is described as a non-programmable type.

https://roofmotors.co.uk/alfa-romeo-convertible-cabriolet-916-spider-roof-ecu-1995-2003

 

Before I start I would like to compliment you on the excellent technical discussion. Thank you!

My problem is this: To adjust the driver's seat electrically, I have to pull the white plug under the seat. Otherwise it will only move about one inch max.

But if I want to open or close the top of my 1996 F355 spider, I have to plug the white plug back in. Then the control unit (Power Packer "DUC1314-11-99" or Ferrari 64660200) pushes the seat forward and back all the way to the rear again.

Is the problem the seat or the control unit 64660200?

 

The problem is most likely the seat potentiometer (if that is what is attached to the white plug). This is a common problem. There is a small plastic part inside the potentiometer which breaks. The potentiometers are either no longer available or hideously expensive if you can find one.

See item 88

https://www.ricambiamerica.com/car-diagrams/ferrari/v6-v8/355-group/f355-m5-2-1996/seats-and-safety-belts-valid-for-spider.html

There is a gentleman in the USA who now makes a 3D printed replacement plastic part with a special tool for assembly.

https://www.ebay.com.au/itm/Ferrari-355-seat-position-potentiometer-drive-repair-kit/143665671697?

You will have to lift the seat (4 bolts) to get access to the potentiometer. There are message threads on the 348/355 forum on how to do this.

Unfortunately, you may have to take the car to a Ferrari technician to recalibrate the seat.