The great saga of my failed relay (presented in parts)

[mighty7]

Please feel free to follow the saga of me chasing down a failed dual fuel injector/pump relay after being stranded on the side of the road one glorious afternoon of touring. I will break down my story into the following areas.

• The drive, the part failure, and getting home story
  
  The initial investigation
  • The pickup
    The relay
    The ignition switch
  
  The campaign to understand the difference between what I was seeing and what the documentation said
  • The crazy amount of extra wiring
    The wiring diagrams
  
  The campaign to clean and update my wiring
  
  My desire to update my diagnostic and maintenance information
  • Wiring schematics
    CAD models by 3D scanning the entire car
  
  The opportunity to correct, fix, update, and improve my spider
  • Use my Tech Shop account to make my own parts

[azruss]

3D scan the entire car. That i've got to see.

[mighty7]

The drive, the part failure, and getting home story

It was a glorious day for a Saturday top down tour put on by my local bay area Fiat club (Fiat America).

http://fiatamerica.com/

We were going to take all the back roads through the Santa Cruz hills and work our way to down into Monterey County to a bunch of commercial greenhouse companies that were having open houses to tour their operations. All of this went off without a hitch. The funny thing is that people always say I am a terror in my spider, but I could not keep up with the other fiat club divers. Many of them have already upgraded to the new Fiat 500’s, but I like my spider and take pride that it is now referred to as vintage. Some pictures from our tours can be seen here.

http://mighty7.homeserver.com:80/Galler ... entID=3092.

This next part of the trip was to go over the Mt. Madonna and Hecker pass road to Morgan Hill for dinner. This is where my spider kept cutting out. I would use the momentum of the car to restart it. This went on for a bit as I was hoping to make it off the mountain to meet up with everyone else to figure out the problem. However on the sixth time the car did not restart and I coasted to the side of the road. Of course my cell phone was dead because I was using the driving map apps all day. A couple of club members stopped with me and let me use their cell phone to call AAA.

There were two spiders on this tour and both had died and needed towing back. We spent some time trying to trouble shoot the issues but eventually we decided that they should join up with the rest and I would wait there for the tow truck. While sitting there I was trying to trace the fuel and the electrical paths to see if I could figure it out.
I had put one of those Lada ignition switches on recently and while trying to gently pull back the rubber boot to see if there was a wire pulled loose I actually pulled them all off. I remember I had a picture I took of the wiring positions back on my computer at home so I started downloading the file using my wife’s cell phone. She was on her last bar and it was getting dark. Then AAA called back to tell us they wouldn’t have a tow truck for several hours. Then the phone died. Great! Now what was I supposed to do?

A couple of other passersby stopped and I waved them off, because I was waiting for the tow truck. While I had run off to the bushes to take care of some business, someone stopped and was leering at my wife. When I got back I chased them away, and when the next person stopped I asked to use their phone and called AAA and read them the riot act. We were stranded on a dangerous curve on a dark winding mountain road and it was getting dark and it was unacceptable that the only local tow truck was just sent off on a 1 hour each way tow job and my wife was getting leered at by strangers. I guess the lady on the phone heard the fear and anger in my voice so they broke down and called a non-AAA tow company to come get us. That still took another 30 minutes, but at least we would get home that night.

It was passed 9pm when the tow guy and I rolled the spider into the garage and an angle that prevented my other classic car from being able to fit inside as well. Ok home safe and now to figure out what went wrong . . .

[mighty7]

The initial investigation: The pickup and the relay

So the next day I get up and decide to tackle the car. It was easy now that I had my photo of the ignition switch to wire that back up and as expected the car still would not turn over. Actually I have started getting in the habit of making computer files with images and photos of all my repairs so I can remember what I did in the past and I don’t have to always relearn as I go. I next used the trouble shooting guide in the “FIAT 124 Spider Shop Manual” (copyright 1990 edition) and start with the ignition system (section 55, page 55.20).

• • Primary input check = 12V check
  • Ground check = less than 0,2 ohm check
  • Coil resistance check = between 0.75 to 0.81 ohm check
  • Pick-up assembly check = should be 700-800 ohm and my meter reads INF fail

So I order a new pickup. When it came in the mail a couple days later I went to install it. I took apart the distributor to get access. It looked great, new even. I checked it again and this time go the 748 ohm. Dang!! I must have been in a rush and didn’t get a good contact before. Back to the trouble shooting guide.

• • Control module check = spark check
  • System parts check = all look good and 4 to 6 ohms on the rotor check

Ok, so it’s not the ignition system. Must be the fuel then. Section 1.0 only has removal instructions that was no help. My old 1979 spider was easy because the fuel pump came on with the ignition switch in the ‘on’ position and you could hear it. However my 1985 doesn’t come on until in the ‘start’ position but by then the engine is cranking and I can’t tell if I can hear it or not. I had my wife crank it and I stick my head up under the car and I don’t hear anything. Hmm, no fuel would do it.

I found the “FI Diagnostics manual” online and go through STARTER RUNS, ENGINE WILL NOT START diagnostic section. Since I already know I can’t have fuel pressure without the pump I jump to step 9 (as step 3d had instructed).

• • Check for voltage at fuel pump = Nada fail
  • Check for voltage output to fuel pump at relay set = nope fail
  • Check voltage input to relay set from ignition switch = 12V check (go to step 12)

This is about where I start to get confused as to what this relay with a lot more than 4 wires is doing. I found a nice write up of the relay on the International-Auto Parts website, called “How the Combination Relay Powers the Fuel Pump”.

http://www.international-auto.com/fiat- ... wiring.cfm

Of course I was still confused. I started hunting online for schematics of the relay and then a little engineering detective work to reconstruct what this little device should be doing. After a good bit of detective work I was finally able to convince myself that International-Auto write up has a typo on their page. I emailed them about it, but haven’t heard back from them yet. Below is the schematic I came up with to help me understand what was going on.


Double fuel injection and fuel pump relay on my 1985 Pininfarina Spider Azzura.

Notice my little path 1, path 2, path 3 markings like in the International-Auto write up. The way I figured it out was to use my battery charger as a 12V power supply along with little alligator clips to get the solenoid to close circuit (“click”) and then test the voltage pass through 88y to 88d.


Setup to test functionality and trace the Fuel Injector Relay Set.

It failed so I ordered a new double relay. When that one came in I confirmed the correct operations again with my DMM and battery charger power supply.

[blakef]

Hey, that's a nice looking diagram, what program did you use for that?

I've also been thinking about 3d scanning the car so I can mess around with the styling in a CAD program. I might give it a whirl with my kinect when I get a free weekend, from what I've read so far though it seems like you would have to use something else to obtain the precision necessary to machine replacement parts, if that's your end goal. Have you looked into any options for this?

It would be great to get a database of CAD files going, I wonder if FIAT's original technical drawings are available anywhere. I've been itchin to get some practice in the machine shop I have access to.

Anyways, sounds like you had an adventure out there!

[mighty7]

I'll post some more information about my 3D efforts in a bit. I have a lot of professional experience with CAD and mechanical design and have also started playing with my Kinect as a 3d scanner. With the stuff I have used at work you could even trace electrical wires in 3D. I'd love to be able to do that on my spider. I like the idea of the community building the models collectively. Let's keep in touch and see if there is something of value here.

I just got a membership at the TechShop which is a high tech machine shop. Not only does it have a full machine shop, but also full CNC, 3D scanners, 3D printers, injection molding, vacuum forming, laser cutting. I am going to take 3D scanning class this week. I'll report back on how it goes, and how easy/valuable it is.

[mighty7]

The ignition switch

My old ignition switch melted inside. That was the previous long ride (albeit almost 6 months earlier). I took the back roads to Half Moon Bay with along with a friend in their Porsche 911. A great drive and great lobster seafood dinner. We said good bye at the restaurant. I don’t think he wanted to keep up with me on the way home. Although his car should be faster, I don’t think he felt as comfortable driving as I do in my spider. I am sure all the spider drivers who are reading this know what I mean. Those little cars just want to be driven.

Anyway, when I put the key in the ignition I just heard crunching mechanical grinding noises. I had to be towed home. Upon investigation the entire inside of the ignition switch was all melted and warped and broken to pieces. Some investigation on line led me to buy a LADA ignition switch. I didn’t have wiring schematics at that time so I tried to write down the way the wires were connected, however the new switch was a little different. On that repair I hadn’t reached the boiling point of poor wiring, poor documentation, and mechanics taking short cuts yet. (Tease: after the current relay failure I have passed the boiling point and will document subsequently in this blog post what I have been doing about every single connection on the entire car).

I got the LADA switch on and the car ran ok. In reading about the spider wiring there is a lot on the blogs about ALL the current going through the ignition switch and people adding relays or bypassing the switch, the brown wire fix, etc. If you recall while stuck on the mountain I pulled all the connectors and wiring from the back of the switch. I also mentioned that I am documenting with pictures (in this age of great cell phone cameras) all my repairs. Although I had wired it back up the way I had figured out before the car still wouldn’t start. I even called a local mechanic and got his directions on how to wire the ignition switch. This is when I ordered the wiring diagrams specific for my year 1985 spider. I had the “Spider 2000 Electrical Diagnostic Manual 1980-1981”, but I would always get confused using it.


Original switch that melted inside

Well, when my wiring schematic came in the mail I learned why. There are differences between each model year. Enough differences so that I would get confused. Anyway I wired the LADA switch up like the wiring diagram and it didn’t quite behave correctly and there were extra wires. A lot of extra wires that I couldn’t figure out where they were going to. On one of my ignition switch diagnostics I had convinced myself that the switch must be dead, so I found an original fiat switch on e-bay and ordered it.

I figured I had melted another ignition switch like all the folks on the internet were complaining about. Upon closer inspection of the wiring diagram I learned that my car had all the power hogs already going through relays (horn, lights, power windows, etc.) So why was my ignition switch burning up then? I decided since I had one coming in the mail I would open this one up. It was completely intact and clean. It started to dawn on me that previous mechanics had been bypassing my relays and wiring components directly. Some of the traditional “Fiat” fixes don’t apply to the later cars as by then Fiat had already built in the solutions.


Disassembly and inspection of LADA switch

With the LADA switch wired up like the wiring schematics showed and tracing and removing all the extra wires related to by-passes, the INT line still had power even with the key out. This confused me. What devices need keyed power when the car is off? Not the clock because it doesn’t go through the key. Also in the 0 position the INT is un-energized. It didn’t make sense. I do have the switch for the European side night lights on my steering column but they have never worked, so I figured it was for them. I was actually excited to have that feature finally work. If you are not familiar there is a left/right rocker on the dash board and when you remove the key you can select the left or right and the side marker lights stay on very dim all night long. This is for the Italians parallel parked on small dark winding roads to keep people from crashing into their car. I assume the lights are dim enough that when one goes to start their car in the morning there is still enough juice to start the car.


How I got the LADA switch wired up (CORRECT WIRING, NOT CORRECT SWITCH/BEHAVIOR)

By this point I was on a campaign to a.) Figure out what was exactly in my car, b.) Return it to as close to the original wiring configuration as possible, c.) Remove all the by-pass wiring, d.) Clean the contacts and ensure the integrity of every connection on the car to.

My new ignition switch came in the mail and when wired up correctly everything behaved correctly.