The GTM Supercar Build Log

Archive for December, 2008

Turn-Signal Wiring Harness Explained

Monday, December 29th, 2008

As promised, here is the wiring explanation for the turn-signal harness. Good pics are hard to get since it’s just a bundle of wires and with all the relays coming in the colors don’t make much sense anyways, but this breakdown should be adequate.

Pin Wire that goes to Pin
A – Emergency Flashers Green Wire from Hazard Relay (#951 dk brown is the Relay Input on black relay wire)
B – Right Turn Signals Wires #925 and #948
C – Left Turn Signals Wires #926 and #949
D – Turn Signal Flasher Wire #952
K – Headlight High Beams Red wire from High Beam Relay (#908 is the Relay Input on black relay wire)
L – Headlight Low Beams Red wire from Low Beam Relay (#909 is the Relay Input on black relay wire)
N – Harness Ground Ground this pin to chassis
R – Parking/Tail Lights Red wire from Parking/Tail Lights Relay (#927 & #929 are the Relay Inputs on black relay wire)
V – Horn Relay Ground Black ground wire that comes from the Painless Horn Relay
W – Battery + (constant) Wire #928 red/black
X – Battery + (constant) Wire #928 red/black
Z – Battery + (switched) Wire #959 orange

Each relay is powered by the hot #928 red/black wire. I ended up using a terminal powered by this wire so I could just run individual wires to each relay to keep things ‘cleaner’.

Wiring Cleanup

Monday, December 29th, 2008

Spent a little bit tonight cleaning up the wiring. Re-routed some wires, fixed some splices, zip-tied the main bundle together, etc. Afterwards I retested everything since I did not test the wiring last night after switching to terminals. Everything worked. Mock wired steering wheel and beeped the horn a few times to make sure I had the it wired properly.

Wiring Progress – Computer Harness Mount and Turn-Signal Harness Completed

Sunday, December 28th, 2008

Made good progress on the wiring today. Before tackling the turn-signal harness completion and beginning cleanup I prepped the computer harness bracket for mounting. The bosses on the bottom of the harness bracket have to be cut off so they sit flush with the frame mounting surface, and the tach module has to be mounted to the bottom of the bracket piece. There was only one way to fit my module onto the bottom of the bracket, but the spot required was right in a corner on the top of the bracket. To remedy this I got out the Dremel and cut out a nice rounded area for the bolt+washer to fit into. After this was done I put the bracket back together and attached it to the frame.

Last night Josh and I decided that it would be cleaner to use some wiring terminals to organize the hot, keyed-hot, and ground wires. Tonight, we mounted the terminals. The hot terminal uses the #959 red/black ‘hot’ wire for its power source. The keyed-hot terminal uses the #933 orange ignition wire for its source.  This is not necessary, but as you can see in the pic, it makes things alot more organized. All the relays run to the hot terminal, as do the W and X pins on the turn-signal  harness.  After mounting the terminals we finished up the remaining wiring on the harness – the horn-relay ground wire and harness ground wire. Once I test this final configuration out I will get a wiring diagram typed up.

After the above was completed I then cleaned up the wiring a bit. The turn-signal harness was temporarily zip-tied to the frame and slack wire was pulled through to where it needs to go. Some excessively long wires that run from the fuse box to the harness were cut and crimped. Some more cleanup remains, but things look a ton better than before!

Floor heating/cooling ducts Completed

Sunday, December 28th, 2008

Since the manual doesn’t really explain this process at all I thought I would take a few extra pics to show how the hosing goes together, and to show where I placed my ducts.

The top plenum on the back of the evaporator is for the driver footbox. The bottom is for the passenger side. For the driver side, I ran the duct tubing (same stuff used for the AC ducts done previously) back under the X member of the frame at the back of the evaporator and to where I planned on mounting the duct. The passenger side I decided to do an easy install and put the duct by the evaporator, as it would be very tricky and tedious to move the duct up a bit farther into the footbox. 

To attach the duct outlet piece you have to attach a small portion of the smaller defrost tubing. Then attach the hose adapter that connects the bigger tubing to the smaller defrost tubing. Zip tie this all into place. With the tubing prepared I ran the ducts back to where I planned on placing them. Using one of the remaining duct outlets I measured out the hole I needed to cut for the duct, and drilled some holes for the mounting screws for the duct outlet. Once I was sure I wanted each duct where I had marked them, I use the Dremel to cut out the holes in the aluminum footbox panels.

With the holes cut all that remains is to attach the ducts to the aluminum with the mounting screws. Since I was working solo I used tape to hold the ducts flush to the holes then screwed them into place. I did not mount the passenger side duct yet as the panel it attaches to needs to be ‘removable’ for a while until the wiring, shifter, and other things that require the tunnel are done first.

When I start doing the sound dampening I will sandwich some mesh over the outlet hole between the aluminum and the sound dampening material.

Hazard Switch Wiring Diagram

Sunday, December 28th, 2008

Here is the wiring explanation for the hazard switch. Posts 1 and 3 have a continous connection, so when the switch is toggled power is moved to post 2, activating the hazards relay.

Post Revision from  06.14.10: The wiring below has been modified to what I have posted here:

Floor Aluminum Installed

Sunday, December 28th, 2008

Taking a break from wiring to do some mindless riveting, I installed the floor panels.

Wiring Update

Saturday, December 27th, 2008

I have been working on and researching the wiring since my last update. The parking and tail light relay is now wired, and figured out the schematic of the 5-pin hazard switch that FFR provides (the manual does not document how to wire this at all) using a voltmeter. I will take a pic of the switch and explain each pin later. All that is left to wire on the turn-signal harness is the horn ground wire, harness ground wire, and the 2 constant battery + wires (pins W and X). I did figure out what wire to use for each pin, and will detail it all once the wiring is completed.

After I finished the parking/tail light relay wiring I hooked up a battery charger to test my wiring thus far. To use a charger to test wiring without worrying about blowing fuses and melting wires set it to a 2amp trickle, hook up the negative to a battery source wire (I used the battery source wire that runs from the fuse panel to the rear of the car), and ground the positive. Since I did not have pins W and X connected yet I ran a wire from the negative clamp on the charger to the 2 pins and temporarily spliced them together. Once that is all setup I used a wire tester with a lightbulb indicator to test various wires. Testing showed that the ignition, headlights (low and high beam relays), parking/tail lights, turn signals, and brake lights are all functional. So far so good!

I also received the ‘white’ plug that handles the fuel pump and cooling fans in the mail and installed that into the UHFB.


Wednesday, December 24th, 2008

It felt nice to get back into things today. Wiring tasks worked on today:

– Drive-by-wire harness created: the donor pallet from FParts cut the drive-by-wire line so that I only had the plugs and a short bit of wiring attached. New wires were ran, spliced together with plugs, and inserted into a wire loom.

– Ignition: wired. Pretty simple and straight forward.

– Turn-signal stalk progress: figured out the relays, installed their grounds, and mock-spliced together the necessary connections. I need some proper fitting shrink wrap for the connections before I can complete them. I am still working on deciphering the W, X, and Z pins. I know what they need, just need to decide what wires to use.

– Brake Switch installed: installed the brake switch and mock-wired it.

– Misc: started the wiring of the central plug in the underhood fusebox (UHFB) – need a bigger connector for the 3-wire splice required.

Once the turn-signal stalk is finally wired I will post a detailed description of all the wiring done.

Transaxle has arrived!

Wednesday, December 24th, 2008

The G50/52 transaxle from Carquip is here. It looks like they did a really nice job on it, plus it came in a nice cooler!

Engine Update

Monday, December 22nd, 2008

Today I received the unfortunate news that the pistons used in the engine build will take 4-6 weeks to arrive. This will push back the project timeline by at least 3-4 weeks. In the meantime while I wait I will do as much wiring as possible without the engine, sound dampen interior panels and doors, heat insulate the inside of the tunnel, etc.