SmarTenna for the NSX
(858) 391-1322 (nights and weekends)
Contact: Bryan Zublin
May 4, 1998
Copyright 1998 Zublin Engineering
This document may be freely copied and distributed provided that it is done so in its entirety. Any change, modification or editing is strictly prohibited without the written permission of Zublin Engineering.
What is the SmarTenna?
The SmarTenna was developed to fix a design deficiency of the Acura/Honda NSX stereo system: when the CD player is active, the power antenna remains extended for no useful purpose. Many NSX owners expressed their dissatisfaction on the NSX internet mailing list, including myself. Being an electrical engineer, I accepted the challenge of designing a device that would automatically "lower that damn antenna."
How does the SmarTenna work?
The SmarTenna connects in line with the CD player cable and monitors the digital communications data that is sent back and forth between the head unit and the CD player. The SmarTenna recognizes when the CD player is active and when it is not active, and controls the power to the antenna motor accordingly. (Unfortunately, it is not smart enough to know when the cassette player is active; in this case, the antenna will remain extended.)
The SmarTenna design has been verified on 1991 through 1997 Acura NSXs with the stock head unit and factory installed CD player (Alpine unit, identified with the NSX logo). The SmarTenna has also been verified on various Alpine CD players that were installed by Acura dealers (identified with the Acura logo) as well as Alpine CD players installed by aftermarket stereo outlets.
Verify that the following items have been included in the package.
Refer to Figure 1.
Open the rear trunk and remove the carpeted panel on the left side of the trunk. This panel is held in place by four black plastic tabs (two on top, one on the bottom left and one on the right side of the panel). A flat blade screwdriver can be used to pry them away from the body.
Figure 1 Removing Panel from Trunk
Refer to Figure 2.
Pull back the carpet near the front left corner of the trunk to locate the cable for the CD player. Unplug the male/female connector pair. The connectors are 8 contact circular DIN type.
Note to owners with Cellular Phones: Please note that the cable and connectors for the cellular phone are in the same vicinity and look very similar to the cable and connectors for the CD player. Because of this, it is possible that you will locate the cellular phone cable before the CD player cable. To distinguish between the two cables, refer to Figure 2. The connector for the CD changer is an 8 contact circular DIN type. The connector for the cellular phone is also a circular DIN type, but it has 12 contacts.
Figure 2 Cable and Connectors for CD Player
Refer to Figure 3.
Plug the SmarTenna DIN connector in line with the CD player connectors. Use one of the small wire ties to attach the SmarTenna twisted cable to the CD player cable.
Figure 3 SmarTenna DIN Connector In Line With CD Player Cable
Refer to Figure 4.
Locate the power antenna motor on the left side of the trunk. Locate connector assembly C553.
Figure 4 Locate Power Antenna Connector Assembly C553
Refer to Figure 5.
Remove the C553 connector assembly from the power antenna metal bracket by pushing in the upward direction. Once the assembly is removed from the bracket, disconnect the male and female mated connectors by pressing the plastic tab on the female connector and pulling the two connectors apart.
Figure 5 Remove and Disconnect Connector C553
Refer to Figure 6.
Remove the 10 mm bolt located to the left of the power antenna motor. Locate the black wire from the SmarTenna unit. Insert the bolt through the ring terminal at the end of the black wire and re-install the bolt so that the black wire is pointing up.
Figure 6 Install Black Wire (Ground)
Refer to Figure 7.
Insert connector C553 (female) into the SmarTenna male connector. Insert the connector C553 (male) into the SmarTenna female connector. Turn the stereo on and select the radio operation. The antenna should go up within 5 to 7 seconds. Select the CD player operation and the antenna should retract within 5 to 7 seconds. If the unit does not operate as described, then proceed to the troubleshooting section.
Figure 7 Connect SmarTenna to Connector C553
Slide the connector C553 back onto the plastic mounting clip (red) that is located on the power antenna metal bracket. Remove the protective sheet from the back of the SmarTenna to expose the adhesive foam. Install the SmarTenna below the trunk release solenoid. For model 2002 NSX’s, please refer to Figure 10. Use a large wire tie to secure the lower connector to the metal bracket. Use the small wire ties to fasten the loose wires together.
Figure 8 Mount the SmarTenna and Secure the Connector and Wires
Refer to Figure 9 (1991 to 2001 model NSX) or Figure 10 (2002 model NSX). Use a large wire tie to secure the SmarTenna to the metal bracket. Re-install the trunk panel.
Figure 9 1991-2001 Model NSX - Fasten the SmarTenna with the Large Wire Tie
Figure 10 2002 Model NSX - Fasten the SmarTenna with the Large Wire Tie
Removing the SmarTenna
The SmarTenna can be disconnected and the antenna operation restored to stock operation at any time. To do this, simply unplug the SmarTenna connectors from the NSX wire harness. Then, reconnect the stock NSX connectors to each other.
If the SmarTenna does not operate as described, there are a few possible causes:
Contact Zublin Engineering (by email or phone) for assistance in correcting any problems. If the SmarTenna needs to be removed, see the instructions above.
To the Southern California NSX club and NSX internet mailing list members for their constant interest in this product which kept me motivated to complete it. To the "San Diego Boys" Raymond Wisco, Mark Johnson and Alan Watkins for allowing me to use their vehicles as test mules and for inventing the name "SmarTenna."