Well, finally another update! One thing and another has got in the way of much development time on the GTR. Besides, it's been far more fun to drive it!
Every time I use the car, I learn more about it and identify areas that can be improved. he cooling issue is better, but I'm not finished yet!! Still, modifications in that area will have to wait for another day.
Today's little mod came to me in one of those 'Eureka!' moments. As you will know if you've been following the build in detail, my GTR has a quick-release steering wheel. Not in itself a problem, but, I also wanted wheel mounted indicator switches and horn button which required some form of electrical connection between wheel and car (one that could be disconnected easily for wheel removal). From previous write-ups, you can see how I overcame this problem with multicore wiring and connectors into the dash. However, in practice, this has proved to be a complete pain in the arse! Twice, I managed to kick out the connector when my foot got tangled in the wire getting in/out of the car as I don't always take the wheel off. I tried curly cable, straight cable, thick cable, thin cable, lockable connectors, DIN connectors - you name it! What I really needed was a system that would have no physical connection between the wheel and car.
One night a few weeks ago, I was in the car park at work, and disabled the alarm on my motorbike. This is done with a remote control encoded, installed in a keyfob. Mine has 2 channels, one for arming the alarm and one to set it off at will. So hang on, I thought, what if I had a 3 channel system that I could use for the left/right indicators and the horn? The transmitter electronics were tiny enough to be either hidden inside, or at worst, attached to the steering wheel and the receiver could sit in the car body where they could be connected to the loom!?!?!!
I spent a quite a few hours scouring the internet for a solution and finally came across a company who could supply the relevant components, based in the UK. A phone call confirmed that they could do a 12V 3-channel remote control system with keyfob encoder (the transmitter actually uses an encoded signal so that the indicators/horn won't come on if I encounter a 'stray' AM signal) and boxed receiver. The items were quickly ordered and came a couple of days later.
I studied the wiring diagrams for the system and worked out how I could patch into the encoder pcb so that I could take fly-leads off to the steering wheel switches. The receiver module operates 3 relays which can be set for momentary, or latched output. I use a momentary relay for the horn so it sounds for as long as you hit the encoder button and latched relays for the indicators so that they work on a switch-on, switch-off basis. This prlongs the encoder battery life as the transmitter buttons only have to operate momentarily.
The wiring was pretty fiddly, but before long I patched the receiver module into the car and made the necessary connections to the Ultima's wiring loom. The encoder in the keyfob was WAY more fiddly. The hardest part was soldering some fly leads to the tiny pcb. Still, after some careful use (and re-use!) of the soldering iron, the system was basically functional. I tested it off the car and all seemed to be working - amazingly 1st time too! So after about 3 hours of fiddling and rewiring later and the system was installed.
What's more - it bloody works!!! As a party piece, with the ignition on, you can even remove the wheel from the car and work the horn and indicators :) No more kicking out the damn cables!! The only pain was that I had replaced the momentary switches on the steering wheel with latchable ones, so to turn the indicators on and off takes 4 presses of the switch! (on/off to turn on, on/off to turn off). I'd reamed out the mounting plate to take these switches, so now have to order another one to refit the simple momentary ones. Still, patting myself on the back for being so darn clever, I tidied up and went home to think about how to reduce the under canopy temperatures!
Re-wired the wheel with new momentary switches. Actually, I had to order another Sparco wheel switch kit - doh! Still, now I've just got 2 red buttons and the horn, neatly packaged on the wheel. The keyfob is sticky-fixed to the wheel so it can be removed for battery replacement and avoids having the unsightly cable ties. Anyway, here's a pic of the final setup.