Help me restore my car phone ('93)

[danoff]

I'm trying to restore the original car phone that was removed from my car. The original phone was removed because of a frayed handset wire. I bought an old bag phone of the same type and transplanted the handset wire and plugged everything in (specifically two things: the phone jack under the armrest, and the switch/mic assembly plug). Unfortunately nothing is lighting up when I apply power (final ignition switch position). I know that the brown center wire in the switch/mic assembly connector has 5V (although that's the only wire that has power). That means I don't think it's a bad fuse. I tried the handset that came with the bag phone, that didn't power up either, and I'm doubtful that both handsets are dead.

Any ideas are welcome. I have some questions for those of you who have had working car phones:

- Does the phone light up automatically under accessory power?
- Do you have to hold the power button to get the phone to turn on? Roughly how long?
- Is the switch/mic assembly always lit when the ignition is in the on position? Or do you have to somehow turn that on?

Thanks.

 

[MotorMouth93]

I would strip out the guts of the car phone and replace it with a small MCU and Bluetooth receiver that would let you make calls with the car phone through any Bluetooth cellphone.

I'm almost tempted to try to find an old car phone and do this now....

 

[danoff]

I would strip out the guts of the car phone and replace it with a small MCU and Bluetooth receiver that would let you make calls with the car phone through any Bluetooth cellphone.

I'm almost tempted to try to find an old car phone and do this now....

I really just want to get the original back in place and turning on. I don't plan to make any phone calls while driving this car.

The phone that I bought to swap parts between is the Motorola Cellular One Bag Phone. It's almost the same phone, cost me $4.25 in an ebay auction.

 

[emac]

If you want to try another phone, post up a picture of the handset, I have a couple of drawers full of old car phones of that era. I may have one that might match or be useful.

 

[warrenw]

You will never get that old phone to work as the old CDMA technology has expired and no longer has base receivers to communicate with.

 

[mskrotzki]

I have a 22 page tiff file of the full instructions for the dealer to install the phone. Prime won't let me upload the file.

I would be happy to email the file, possibly convert it to a file I can upload, or get it to you some other way if you are interested.

Let me know

Mark

 

[danoff]

I have a 22 page tiff file of the full instructions for the dealer to install the phone. Prime won't let me upload the file.

I would be happy to email the file, possibly convert it to a file I can upload, or get it to you some other way if you are interested.

Let me know

Mark

Thanks. That will be very helpful. I PM'd you my info.

 

[Old Guy]

You will never get that old phone to work as the old CDMA technology has expired and no longer has base receivers to communicate with.

I am thinking exactly the same thing, except that being 1993, the hardware might predate CDMA - more like pure analog. It might make an interesting non functional period correct dress-up piece if you were entering the car into a classic car show. It would match right up with the head unit cassette drive and would create equal levels of confusion for anybody born after 1995.

 

[danoff]

At the moment, my best guess is that it doesn't work because the stereo doesn't work. That's the only thing I can think of that would be a problem with any of the connections the handset is connected to. There could be another component somewhere in the chain that is broken, but if that's the case it may stay broken forever.

 

[Old Guy]

See if can find or better yet, borrow a copy of the NSX Electrical Trouble Shooting Manual for your model year. Unlike the regular service manual, the electrical manual covers the wiring for the NSX accessories (I think there were only two accessories, the phone and the remote entry). Contrary to its name, the trouble shooting manual does not provide any guidance on trouble shooting electrical problems; however, it does provide very detailed wiring diagrams by system including connector numbers and pictures of device locations and it covers the accessories. With the diagram showing the telephone wiring connections to the vehicle harness, you may be able to figure out how the phone was supposed to operate, or if there is another missing component.

 

[danoff]

See if can find or better yet, borrow a copy of the NSX Electrical Trouble Shooting Manual for your model year. Unlike the regular service manual, the electrical manual covers the wiring for the NSX accessories (I think there were only two accessories, the phone and the remote entry). Contrary to its name, the trouble shooting manual does not provide any guidance on trouble shooting electrical problems; however, it does provide very detailed wiring diagrams by system including connector numbers and pictures of device locations and it covers the accessories. With the diagram showing the telephone wiring connections to the vehicle harness, you may be able to figure out how the phone was supposed to operate, or if there is another missing component.

The wiring diagrams for the phone are in the handout for the handset installation instructions that I got from mskrotzki. There is a controller behind the seat that could be broken, and one in the trunk that could be broken. However I have no reason to suspect that either of these are broken, so I'm not particularly inclined to spend a lot of time or money to diagnose those boxes. The handset was removed from my car because the connecting cable was frayed (I have the original frayed cable).

Since the dash control is receiving power (but not responding to the received power) I know that at least that cable is connected behind the seats. It would be weird to remove the trim behind the seats to pull the plug on just the handset, but leave the cable tucked under the armrest, which is what they'd have had to do if they disconnected the handset at the control box.

There is one item that is connected to the phone, which is the stereo, which I know is very dead. My guess is that somehow the stereo being dead has taken out the phone. It is part of the connection because the call reception connects to the car stereo system and into the car speakers (if I'm reading the manual correctly).

The big payoff here is just to get the handset and the switch panel on the center console to light up. That's it, just illuminate, maybe accept some number pressed. So it's not like it's wildly important. I wasn't going to hook it up to service, and I wasn't going to make phone calls with it while driving. It's just a gee-wiz part of remembering how the car was originally configured. I'm not sure it's worth shelling out the cash to get the stereo functioning again to see if the phone lights up either. We'll see. If I find the right deal on a working stereo I may go for it.

 

[mskrotzki]

I have my whole phone packed up in a box that lives in my basement. It was about 12 years ago that I removed it, but if memory serves (a $64.00 question) pushing a button on the keypad would give a dial tone through the stereo. I do not recall if any buttons lit up (it was always daylight, or if you heard button tones. I just don't remember.

I saved the phone to do exactly what you are doing -- return it to 1993 if they ever got to collector status.

If you feel like it, we could get together and swap out the two controller units. However, I'll bet you are spot on pin pointing the stereo. I'll stop short of offering to disassemble my center console to swap out my (very much operating) stereo. Of course that would be an opportunity to put a drop of oil and adjust the aspirator fan . . . .

If you've read my thread on repairing (for $0.00) my retracting antenna, you'll get an idea of where I'm coming from.

http://www.nsxprime.com/forum/showthread.php/203504-Retractable-Radio-antenna

 

[danoff]

I have my whole phone packed up in a box that lives in my basement. It was about 12 years ago that I removed it, but if memory serves (a $64.00 question) pushing a button on the keypad would give a dial tone through the stereo. I do not recall if any buttons lit up (it was always daylight, or if you heard button tones. I just don't remember.

I saved the phone to do exactly what you are doing -- return it to 1993 if they ever got to collector status.

If you feel like it, we could get together and swap out the two controller units. However, I'll bet you are spot on pin pointing the stereo. I'll stop short of offering to disassemble my center console to swap out my (very much operating) stereo. Of course that would be an opportunity to put a drop of oil and adjust the aspirator fan . . . .

If you've read my thread on repairing (for $0.00) my retracting antenna, you'll get an idea of where I'm coming from.

http://www.nsxprime.com/forum/showthread.php/203504-Retractable-Radio-antenna

I may take you up on that at some point. Probably what I would do is try my handset out on your system, just to make sure that the handset works. For now, I think I'll keep an eye out for a reasonably priced stock stereo that works (ha!).