Solved Any electronic gurus on board here? Need auto radio assistance.

[carwiz]

I've got a 1992 Ford Taurus LX in the shop with radio problems. Ordinarily, this would just be a replace with an aftermarket unit and be done with it. (PnP) However; this car has less than 80K miles, and looks like it just came off the showroom floor and the owner wants to keep it original. And with the redundant radio controls near the instrument cluster. I had the car in about 5-6 years ago for some belt maintenance and AC work and the owner doesn't want anyone else to touch it. I hate to disappoint the owner.

I got the radio to work but it won't stay working after cycling the ignition. It will make sound like a two-tone wave siren by unplugging the power connector on the back and plugging back in several times until the antenna goes up and it starts working. After that, everything works. That is until the ignition is turned off. The antenna goes back down then it's back to dead--No sound, no lights, no nothing. I checked the pins and none seemed loose. All the wires are fully inserted in the connectors. It's like it has a bad capacitor or maybe a PC board is cracked. ??? It's odd that it will work until power is cycled even through a "jiggle test".

 

[Layback Bear]

I would suggest unplugging the power antenna and install a old fashion antenna for testing. See if that helps. The power antenna motor have been known to go bad and cause crazy feed back to the radio circuit. Sometimes a sticky antenna when going up would cause problems. It would cause a high amp draw.

Raise the antenna and clean and lubricate with a high quality spray silicone.


I'm just going by memory.
I no longer have access to Ford Motor Company manuals.

Normally manuals didn't do much good for these kinds of problems anyway. There isn't much one can do other than replacing parts and checking connections. For sure check for clean and proper grounds.

Their is also a chance that the radio is loosing it's memory caused by lack of voltage/ground when the ignition is turned off. If I remember correctly their is a fuse for that. The owners manual should show fuses. Their might be more than one fuse sometimes located in different fuse boxes. If this car has remote buttons on the steering wheel; those button and circuits have been know to cause problems.

Ask your friendly Ford Dealer if their are any TSB"s for such a problem. Be sure they also check for Radio loosing it's memory.

TSB = Technical Service Bulletins.

If a little more memory comes back, I will post more information.

Do you have access to a N.G.S.?

Amazon.com: HICKOK NGS XL FORD MASTER KIT: Automotive

 

[carwiz]

Thanks for responding Jack. This is EEC-IV (OBD-I) but yes, I have an equivalent scan tool and analyzer. Not much given under OBD-I.

I have the TSBs but nothing there but a RFI filter on the fuel pump. It doesn't apply.

Fuses, wiring and connector pin outs were the first thing I checked with a dead radio. But your idea on the antenna is valid. It has a 6-disc CD changer with a control module between the radio and antenna. (Injects CD play through RF signal and disables antenna mast.) I'll have a look at bypassing that but power to the mast motor isn't there until I get the radio to power up. I'm pretty sure it's the radio itself at this point and I'm dreading the thought of dealing with an Ebay replacement.

I'm off to the shop.

 

[Layback Bear]

EEC-IV (OBD-I) will not be much help for this kind of problem.
Their might be a remote switch and speaker test.
It's hard for me to remember that far back.

All test are valid.
Where is the audio module located. While I'm trying to remember 2 decades back.
Is it a separate module that could be mounted in the drivers door, trunk or mounted to the floor. Any and all these location could have a moisture problem.

From post #1

I got the radio to work but it won't stay working after cycling the ignition.

This indicates that their is a power loss at times. This can be a power loss internal or external of the radio or a loss of ground.

After checking fuses, corrosion on the connector side of the fuse box and all ground connection including the ones behind the kick panels where many main ground are located for the main dash harness I would check the ign switch and if their are remote switches check them.

***A little trick.***

If you have a friend that can help.
Turn the radio on and do a wiggle test and have a friend listen for any changes in the static or normal sound.

Ford audio system are very sensitive; it doesn't take much to make them go goofy.

Let me know how things go with the antenna or whatever.

If you have a friend in the auto junk yard business you could do the swap parts test on main components. Doing this could save a lot of time and money spent.
In the Dealership we did this to save time but we used our parts department.

The bad news. You could have more than one problem.
If you have any question just ask and I will try to remember back and come up with something. I did this kind of of repair for 40 years and much of that time in Ford Dealerships. All I have to do is remember.

 

[carwiz]

Well, it's definitely in the radio itself. After isolating the CD player module from the radio, it still did the same thing. Then I remembered I had a 94 Ford radio in my stash. It was from an Aerostar and has the same connections except for the redundant control. I plugged it in and zoom-zoom, it worked perfectly through key-on, key-off cycles. So I made a few calls around and located a replacement. I'll go check it out tomorrow and make sure it works. I had a feeling it was internal from the startup sound it made initially. But it worked so well when it did work.

Thanks for the help, ideas and holding my hand on this. Sometimes it just takes another pair of ears.

 

[Layback Bear]

Happy for you. The old swap and test seems to have worked for you.
Yes sometime just talking about the problem will bring up ideas.

Don't forget to lubricate the antenna.
I have seen a few power antennas that the gears lube in them would dry out and cause the large amp. draw. A few I have saved by removing the cover and cleaning and replacing the lube with disc brake silicone lube.

I have even seen power window motors with the same lube problem when they get old. It only happened on some year Ford cars but I don't remember which years.
I have a lot of old car maintenance tricks that in the long run save a friend a lot of problems.

 

[carwiz]

I've been restoring antique and classic cars for a number years so I've "walked the walk". The last few years I seem to have gotten locked into Model Ts. Word gets out and it's easy to get swamped but I'm close to calling it quits to spend some time with my own cars. This place is beginning to look like a salvage yard so I gotta get on them while I'm still able. I sure don't want to see them turned into Chinese anvils.

 

[Layback Bear]

Old cars restoring is great fun but as you well know it takes a lot of time and money.
You have to be in the business a long time just to know the right people and business to get what you need at a proper price.

A friend of mine owned a machine shop that rebuilt engines including all machine work needed and assembly. I helped on many and was amazed on how much things cost for old engines. Simple things like rings, bearings, pistons, valves and gaskets. We had a shop in town that restored antique and classic cars and it took years to complete one. Either he was waiting for the customer to come up with more money or waiting on parts.

I have created wiring harness for kit cars and rewired a few old corvettes.

People seem to think this can be done in a few hours and cost a couple of hundred of dollars. WRONG Lots of time and money.

If one has to ask the price they can't afford it.