Paradise Garage | ||||||||||||||||||||||
We recommend Internet Explorer set to 1024x768.
© 1999 Brian F. Schreurs
Buy our book! |
The problem with automatic transmissions is that there's no good way to tell how they're doing.
They run fine until one day it shifts a little slower or makes the dread "funny noise." Even those
few who can find the trans dipstick often don't know the proper test procedure, and even under
the best conditions diagnosis usually ends with "whoops, better start saving up." We did not want this fate to befall the visiting 1995 Mustang GT. Even though we're dying for an excuse to drop in a five-speed, total transmission failure is not the route we have in mind. We've already installed a transmission cooler but we thought it'd be nice to keep an eye on things. To this end, we're installing an AutoMeter electrical transmission temperature gauge (#2640) which we're mounting in a Mustangs Unlimited dual- gauge A-pillar pod (#77L409).
Remove the transmission pan. It's held on by a zillion 10mm bolts. The best way to avoid geting soaked is to remove the side bolts first; then the rear bolts; then the outer front bolts (now you'll start seeing fluid); and finally, slowly undo the last two front bolts. Be sure to have a catch pan and an oil eater mat.
Now you need to put a hole in the transmission pan. Our kit came with two different plugs, one substantially larger than the other. We decided to install the larger plug because it gave the sensor much more contact area with the trans fluid. By some happy coincidence, the larger plug is the exact right size to use a 3/8" hole cutter on a power drill. The hole needs to be placed somewhere on the pan where it will not interfere with any trans parts. Clearances are tighter than they look so be careful making your selection. We chose the flattened corner on the left-rear of the pan. Once the hole cutter has done its work, the hole will likely need to be widened slightly with a rat- tail file. We do mean slightly -- just enough to get the plug to screw in. By the way, when you screw the plug in, it goes in with the hex-side out.
If you're like us, you don't have fancypants brazing equipment lying around. Find yourself a welding shop to do this part because it's important. Get that plug brazed in place so that it won't move or leak. It should only cost a few bucks -- $15 in our case, done by Erin's Welding in Woodbridge, Va. And no, thread sealer or thread tape are not acceptable substitutes for getting it done right. Insert the temperature sender, using thread sealer to keep the trans fluid where it belongs. Put the pan back on. (That missing bolt is in the drain, no need to thank us.) Wire up the sender. You'll also need a ground wire so you might as well take care of that right now by grounding to one of the transmission pan bolts. Be sure to use 18-gauge wire, and remember it has to reach all the way to the A-pillar so use a lot of it.
Had we been thinking, we would have poked a hole in the center of the grommet and run the wires through that. We weren't thinking, however, so we just took the grommet out and ran the wires through the big gaping hole. When we went to replace the grommet we had to cut a notch in it for the wires. Oh well. If you're attaching more than one gauge, stop here and wire the other sender as necessary. We also hooked up an oil pressure gauge. The rest of the work is done inside the car. Note that if you're installing more than one gauge, all these instructions apply to all gauge wiring. If you haven't already disconnected the battery, do it now! You'll be working around the air bag and they don't like being disturbed. Remove the plastic trim covering the A-pillar on the driver-side. It's easy; just pull hard. Take the dashboard apart. To get the front fascia off, you must first remove the headlight knob. Pull the knob to its full-open position and look for a slit near the base. Supposedly there's some sort of clip in there that you just loosen with a pick or punch, but we dunno. We just fiddled with it for about a half hour till it fell off. It'd probably be easier to just buy a new one and break the old one off.
This will give you access to run wires from the grommet to the A-pillar. Instead of trying to shove the wires up through the dash (you can't push a rope), use a spare length of wire as a guide line. Start at the A-pillar and route it down through the dash, to where the sender wires are waiting. Tape the sender wires to the guide wire and pull them back up. It may take more than one trip since you'll likely have a fairly large wad of wiring to cram through some fairly small openings. Here's a quick inventory of the wires you'll be running:
You're already routing the sender and ground wires up. You'll also have to route the power and illumination wires back down. Before you connect the wires, you should position the gauge in the A-pillar pod. Basically, the gauge has two mounting studs that get in the way of everything. Use a hacksaw to cut them off. Now the gauge should just press into the pod without any trouble. With the gauge in the pod, continue the wiring job. The sender wire and ground wire should already be attached on the chassis end. On the gauge end, they attach to the gauge posts as labeled. If you lose the label, it's also stamped into the housing. In fact, all the wire posts are carefully marked on the gauge end. Just follow the diagram on the back of the gauge, and we'll help with the chassis side. The gauge power wire needs to get ACC-on power (i.e., it's off when the car is off but it's on with the key in the ACC position). We already have ACC-on power because of our Foglight Switch but you'll find plenty of wires to choose from under the dash. Just use a multimeter to find a wire that meets the criteria. Now, the gauge needs to light up when the parking lights are on. The headlight switch is right there, so it's easy enough to tap into that and run the gauge in series with the parking lights. Wrong wrong wrong wrong wrong!!! Ford has some bizarre setup in the headlight switch, wherein it receives power when it's off and no power when it's on. If you tap into this, your gauge lights will work exactly opposite what you want. Not that we did it or anything. Not us. Nope. We heard about it somewhere. Yeah. The illumination wires need to tap into power and ground for your parking lights. You can look around for the harness under the dash if you want. It's gotta be there somewhere. We cut out the middleman and went straight to where we knew the circuit would be the way we wanted: we spliced into the wiring harness at the front-driver parking light.
Use a blade to cut away some of the plastic insulation, then use a multimeter to determine which power wire is the parking lights (you don't want your gauges to blink with the turn signal do you?). Run the illumination wires out to the harness (we just followed the route we already used for the Fan Switch) and splice the power wire into the harness. Then put the insulation back on and tape everything up. The ground wire can ground on one of the green screws just next to the battery, on the radiator support. Easy. Then put the marker light back together.
Put the factory A-pillar trim panel back in place. We're using self-tapping screws; the tape is worthless. Wedge the pod as far down on the A-pillar as it will go. It should sit there on its own, although it might pull away a little. No matter. Check for fit and to make sure all the wires are tucked away.
Slip the screws into these caps, then get in the car and hold the gauge pod in position. Line them up, one on each side of the pod's curve, and just push. They'll screw into the aftermarket and stock trim panels with a little effort. Close the caps to hide the screws. Put your dashboard back together! It should all go okay, without surprises, except that the headlight knob will be as hard to get on as it was to get off. Hook up the battery and go! You're done!
Man oh man that was a lot of work. But the new gauge looks really, really cool. With this much engineering involved, AutoMeter is a little misleading about the ease of installation. That's okay though, most people probably pay a pro to do something like this. For us it's another notch in the tool chest.
|