Sunday, June 26, 2011

Study for license upgrade nearly complete

I have been studying for the Standard license upgrade course with Paul Hoffman, VK5PH, for the last three months. 12 weeks on a Tuesday evening with a dozen other hopeful students.

Well the last class was last week and I have a few things I need to re-read. Given my results on the in class practice exams, Paul has suggested I actually sit the Advanced theory first instead of the Standard theory. On the Advanced practice exam I would just scrape a pass mark. Not confident enough just yet. Good news is I am pretty confident about getting 90+% for the Standard theory and the Regulations.

The exam in this coming weekend. So I have to make up my mind about which exam to sit. I would love to do the Advanced and be done with it.

I have a couple of topics that I am not confident yet, mainly Valves, transmission lines and antenna loading. I have four nights free this week, so I will read up and see how things go =)

The really hard part is choosing to let the ACMA/WIA give me the next available callsign or choose one of my own. $5 or $20 respectively. Decisions, decisions...


Big trouble in little Corolla

The little Corolla has been getting steadily worse in the starting on cold morning. Saturday it stopped working all together. Hey I can use a screwdriver and sand paper! This looks easy, the internets tells me this is a common problem with Corollas and is a twenty minute job. Famous last words!

So, after disassembling the solenoid on the starter motor of the car, including un-soldering the solenoid winding from the cap. I cleaned the main starter motor contacts. They were a mess, so I sanded them back and tried to clean all the black gunk off. I cleaned all the other conductors and reassembled. As you do...

Then bolted the starter motor back in the car, tried to start it. Nothing.


Fiddle around with key switch wiring, contacts, etc etc ... nothing. There was only 6 volts on the ignition key switch to the solenoid. Not sure if there is lots of lossy connections between the battery, switches etc. Bother.

Find battery is a bit low on the volts. Put the battery on to charge, went over to a friends place for diner. Got home, the battery seemed to be charged suitably. Went to bed.

Got up this morning, to ponder the issue of there not being enough volts on the ignition wire, scour the internet for more ideas. Walk to servo to find a relay and connectors, etc. They had nothing. Zip. Bother...

Go home, listen to the WIA broadcast and ponder other possible solutions.

After a couple of phone calls shuffling my calendar, I walk half an hour into town to find Sprint Auto to find these parts. Sprint Auto was closed. Was not liking my luck at this point. Walk to Repco. \o/ Its open! Speak to geezer about what my problem is and what I thought might be a suitable solution about not enough volts on the key switch. He suggested that it sounded reasonable, but I would be better off waiting until tomorrow to find an auto-electrician or get a reconditioned second hand one. I needed the car running today. Things to do. With a lighter wallet and a pocket full of parts I walked half an hour home.

Got home grabbed some lunch, had another look on the internets to see if I could find someone else with a similar problem or at least a circuit diagram and repair manual type information. At this point I knew there was something that I did that was amiss. Couldn't quite put my finger on it.

Build up a relay that is trigger by the ignition swith from the key, powering the solenoid from the battery direct to get more current through to pull the solenoid in. The solenoid wasn't moving, but the motor was turning. This was very, very wrong.

Realize that maybe the solenoid was actually dead, maybe a broken winding. Decided to pull the starter motor off the car and ponder some more. I couldn't actually find anything on the Bosch model at all. There were a lot of NipponDenso models that looked similar. At this point I started comparing any starter motor for the 4A motor I could find. At some point I noticed that the large contact studs on the back of the solenoid were wrong. The short stud was on the top, away from the motor and the long stud was on the bottom, closest to the motor and connected to the positive cable for the starter motor. Hang on a second...

So at about this point I looked at a service manual for an AE86, which is a different model, but gave me the most detail for an 1988 corolla I could find. The schematic on the AE86 go me thinking about why the motor was spinning without engaging the solenoid. You got it, I had put the thing in upside down and solder the wires in back to front in the circuit.

After another half an hour, I had assembled it the right way and put it back in the car.

Not expecting it to even move the solenoid, the car car started smoothly and ran! So I switched it off and added my ignition relay, and that started nicely too. So I tidied everything up and took the car for a lap around the block, to be sure.

Half hour job, eight hours later! At least its working properly now and we can now go do those things we need to do. =)