The electric aerials on Mk1 MR2's don't last forever. Toyota charge rather a lot for replacements, so this is my cheaper solution.
Since writing this article, I've found another website on the same subject. You may want to read both as viewing the same subject from two perspectives may make things a bit clearer. Click here.
Things you'll need:
A fully automatic electric aerial
Electrical terminal ("chocolate") block
Cable-ties or insulation tape
Before you start
Before we start, understand that this procedure will cause the aerial to extend and retract when the standard radio is powered on and off. The car that this was performed on was a late spec 1987 model. Wiring configurations and colours may be different for other years, and previous installations may complicate the issue. I would advise checking voltages on the connector pins before cutting anything or wiring anything up.
Buy an aerial
A fully automatic car aerial can be bought from Maplin Electronics (code RJ98G) for about 25 quid.
Remove the fuse for the stereo stuff.
Remove the boot lining
This is extremely easy, and can be done without breaking any clips - something that Toyota themselves sometimes seam completely oblivious to. To remove the fixings, simply push the centre pin in and then pull the fixing out. You'll probably need to remove the rear, right and front lining.
Disconnect the old aerial
Coming from the front of the car towards the aerial is a big bunch of wires. If you're lucky, this will be in the same state that it was in when it left the factory - that is tidy and bundled up. There will be a connector block coming out of this bundle of wire, and also the black aerial wire itself. Disconnect the white connector block, and pull the big black aerial wire out from the aerial (it may have got slightly corroded, so give it a good tug).
Remove the old aerial
Time to get busy with a screwdriver, and unscrew everything that connects the aerial to the car. Keep the screws and remember where they came from! You'll also have fun unscrewing the aerial where it passes through the car to the outside world. I can't remember for sure (oops, sorry) but I think the chromed top bit unscrews. I had to get a pair of mole-grips on this, but I think there's a tool that pokes into little holes in the top and allows you to twist it that way. If you completely mess up the chrome bit, it doesn't matter because it will all be replaced by the new one. Once you've extracted the old aerial, pull off the rubber tubing from the bottom as you'll need this for the new one. Put the aerial to one side - you shouldn't need it again.
Get the electrics sorted
Now you'll need a pair of wire cutters. You need to cut two wires going into the connector block as shown in Photo A. The wires are Blue with a Yellow stripe (+12V supply) and Pink with a Blue stripe (aerial up/down signal). If possible, check these are the correct wires for your car by using a voltmeter (you'll need the fuse in to do this). Give yourself some slack with these wires by extricating them from the tied bundle (you may need to cut the ties to do this, so once you're done re-tie the remaining wires). The Maplin aerial has three wires (Power/Red, Ground/Black and Signal/Green). The Red and Green wires are terminated with crimp bullet connectors. If you've got all the crimping gubins then by all means use these; I don't have any so I'm using a terminal block here. Cut them off and bare back about 3mm of wire, twisting the strands once you're done. Do the same for the wires you've cut from the connector block.
Fixing the new aerial in place
Now this is where things start to get a bit tricky. Supplied with the aerial kit you get a metal bracket which needs some "adjusting" (I recommend using a pair of mole-grips and pliers for this). Take a look at the Photos B and E to see how I bent the bracket. You'll notice that we are re-using one of the screws from the old aerial to secure the metal bracket in place.
Take one of the longer pieces of rubber tubing (saved from the old aerial) and attach it to the water drain connector on the bottom of the aerial. Assemble the top of the aerial as per the aerial instructions (the metal ratchety thing may need some squashing so that the tabs fit through the hole) and fit it in the gap left by the old mast (see Photos C and D). Cut the rubber tube so that it can attach to the car water drain connector without any kinks (don't cut it too short!). Ensure the aerial assembly is straight. Now attach the modified bracket to the car, and tweak it so that it lines up with the fixing point on the aerial. Secure the aerial to the bracket. If the bracket is not adjusted correctly, then the aerial will extent at an odd angle from the car.
Just for the record, this took me numerous attempts. It isn't easy getting the mast correctly aligned, and the connector at the top can be very fiddly.
Now we can finish wiring the aerial up. Take your terminal block and join together the Blue wire with a Yellow stripe with the Red wire. Join together the Pink wire with a Blue stripe with the Green wire. Tie the terminal block securely to the aerial bracket and wrap it tightly in insulation tape. Use the supplied nut, bolt and washer to attach the Black wire from the aerial to the aerial bracket. See Photo B. Connect the aerial leads up. Plug the fuse back in. Give it a whirl. If it all works, put the lining back. To re-use the lining clips, push the central rod out so that it protrudes from the face of the clip. Insert the clip then push the central rod back in so that it's flush.
Click the image to see the full size photo
The connector block with the two wires cut
Joining the two cut wires with the two aerial wires.
Connecting the Ground wire.
Adjusting the mounting bracket.
The mast from below
The mast from above
The complete assembly
This is what I did with my car, but it may not necessarily be the same process for your car. Check everything you do with the manual supplied with your aerial. I take no responsibility for problems arising from aerial installations that have gone wrong.
Last update : 06 November 2004