Currently if I connect my power antenna connector in the trunk and turn on the radio the 20A fuse will blow. So I started troubleshooting today and I have some basic questions about its operation.

Test #1

When the radio is OFF there is +12V on the RED/BLUE wire only.



Test #2

When the radio is ON there is +12V on the BLUE/RED wire only.



Test #3

When testing the power antenna plug it's odd that there is is continuity on all three plugs. I believe the internal switch in the power antenna could be broken. because getting continuity on all three terminals doesn't seem to be normal. Any thoughts?

A high level picture of all the connectors...




So to summarize.. It appears that the internal switch in the power antenna seems to be the culprit because the car is alternating 12V on two different leads depending on whether or not the radio is on or off. If anyone has any thoughts or ideas on the normal behavior please let me know. I'm just glad it appears to not be a problem w/ the radio or the cars wiring harness.

 

OK.. Looking at step one and now reviewing the FSM it appears I have normal activity in regards to the car's wiring and radio switch operation.

 

Does anyone know where the power antenna relay is located?

 

There are rewiring instructoins somewhere on the BBS so that the antenna retracts when the key is off. I have them on my palm and will upload if necessary.

 

I seem to be getting the correct power from the radio ON/OFF perspective. It appears to be a problem w/ the actually antenna. It seems the switch inside the antenna could be crapped out. I need to do the following test.



Tell me if you think this is odd... If you look at the picture below, the 3-prong electrical plug my antenna has continuity on all three prongs. I don't believe this is the normal condition. I mean there has to be a demarcation btw +/- voltage I believe. Does anyone have a power antenna lying around that could check for me?

 

The power antenna relay can be seen on page 50:35 section 50J of the FSM of the 85RX7 Wiring Diagrams section. It shows it under the dash up toward the gas pdeal.

 

Thanks. I'll do the tests they show on there. Again, I'm getting the correct voltage w/ the radio ON/OFF switch so I think it's the antenna that is FUBAR. I mean why else would the fuse blow if the radio is turned on and the power antenna is connected? There has to be a short somewhere to blow a 20A fuse. I'm just wonder what with the antenna unit that could have failed to cause this and why is there continuity on all three leads on the antenna?

 

My bet is on the anteena also. You've already found the answer. When the antenna is unplugged, the fuse does not blow. With the anteena plugged in, the fuse blows. I went with one of those "rubber ducky" type anteenas. The power ones are just a pain.

 

True.. I like the look of the fixed antenna, but I'm trying to keep this car as close to OEM possible. Right now it's 100%.. authenticity is my goal, even if it's not always the best solution. I'm not even sure if power antennas can be located for these cars any more, I mean I'm sure I can find a working motor, but is it possible to replace a broken plastic cable that actually makes the antenna move?

 

Replacement power antennas are available at most autostores for about $50. Look for the 'import' model. I have 3 more of the old RS antennas stockpiled for the future: got 'em for $15 on sale.

 

I've bought just the plastic cable before. I never could get it to work correctly. They sell aftermarket power antennas that a very close to factory. I'm sure that the power antennas from the newer model cars could be made to work and look close to factory that you couldn't tell.

 

The power antenna is a Universal Import type with a slightly different mounting bracket (you have to re-bend the bottom because the screw orientation is rotated 90degrees, oval out the bottom screwholes, and drill a thruhole for the drain tit).

 

Thanks.. I'll pick one up @ VatoZone and see if I can get it to work. Right now my little Rx-7 is just running around fully erect.