1993 Caprice Classic Wagon - Radio Display Always Lit

Here's an interesting problem to have (note carefully the position of the key):



Yeah. The radio/clock display is staying lit all the time. It is worth noting that the radio cannot actually be turned on when the key is off or removed. There is a power antenna and it appears to be functioning normally. As far as I can tell, it is the factory power antenna. Only the clock display is functioning. This suggests to me that the malfunction is internal to the radio.

I thought that when I bought the car, the clock display was only lighting up when the doors were opened. Now I'm not sure. I wasn't really paying attention.

I tried pulling the radio fuse, but it did nothing to make the display shut off (probably because it's still getting backup power from someplace. Nor was it blown or damaged. The radio seems to work perfectly otherwise.

I'd definitely like to fix this and keep the car as original as possible.. It is running the battery down every couple of days and probably isn't doing wonders for the emission of the VFD panel. If it comes to this, what Delco radio service facility is generally recommended?

Well, it's a guess that it's shorted somewhere. As you noted, it should not be on in the key off position, but it is. I'd check to see if anything also works when it's NOT supposed to. Maybe windows? Heater controls? Rear window defroster?

At least it would give suspicion that it's a short in the switch, which I would suspect as the most likely cause. Where else would it be getting power from?

There are two wires from the radio that are hooked up to power. One is to B+ to keep the memory of stations and time, the other is to power it up when it's in KEY ON. Might have a rubbed short there. but I'd still check the other stuff first.

lakeffect wrote:

Well, it's a guess that it's shorted somewhere. As you noted, it should not be on in the key off position, but it is. I'd check to see if anything also works when it's NOT supposed to. Maybe windows? Heater controls? Rear window defroster?

At least it would give suspicion that it's a short in the switch, which I would suspect as the most likely cause. Where else would it be getting power from?

There are two wires from the radio that are hooked up to power. One is to B+ to keep the memory of stations and time, the other is to power it up when it's in KEY ON. Might have a rubbed short there. but I'd still check the other stuff first.

Nothing else that would normally work with the key on continues working with it out/off. The radio won't play with the key off/out. (I've tried it.)

It's possible to press the volume knob and get a momentary time display. A circuit then turns the display off after about five seconds. I believe this feature runs solely from the B+/memory line. I'm wondering if the circuit responsible for this feature could have failed in the "on" position. (I did test a working Delco radio to see what happens if the pushbutton becomes electrically "stuck". The radio display still blanks out after about five seconds in that case.)

I don't (yet) have an FSM for this car. It's on my list of things to do.

several hits on Ebay for a 1993 Caprice FSM

http://www.ebay.com/dsc/i.html?_fspt=1&LH_TitleDesc=1&_sacat=0&_mPrRngCbx=1&_nkw=1993+caprice+factory+service+manual&_sac=1#seeAllAnchorLink

http://www.ebay.com/itm/1993-CHEVROLET-CAPRICE-FACTORY-SERVICE-MANUAL-93-CHEVY-/290751854701?pt=Motors_Manuals_Literature&hash=item43b229386d&vxp=mtr

http://www.ebay.com/itm/1993-Chevrolet-Caprice-Service-Shop-Repair-Manual-OEM-/160855841228?pt=Motors_Manuals_Literature&hash=item2573c159cc&vxp=mtr

lakeffect wrote:

several hits on Ebay for a 1993 Caprice FSM

Thanks for the links. I was going to wait until my wallet had recovered from the arrival of a rather...large...automobile, but that was much more reasonable than I was expecting it to be.

I'm sure I can drive the car at least once a day until the book gets here. Sacrifices, no matter how painful, must sometimes be made.

GM must have used a very good quality display in those radios. I've never seen one that had dimmed (evenly or not) much, even in some extremely high mileage cars.

You could just disconnect the battery until the FSMs get there!Makes me curious about touching
the volume knob to get a momentary time reading.Mine may do this as well and I didnt know it
which is no surprise.Would be a nice feature though.

Flasheroo wrote:

You could just disconnect the battery until the FSMs get there! Makes me curious about touching
the volume knob to get a momentary time reading.Mine may do this as well and I didnt know it
which is no surprise.Would be a nice feature though.

Why would I do that when I can spend some quality time driving the good old Road Sofa around?

On the AM/FM, AM/FM Cassette and "premium" audio system, you can press the volume knob down until it clicks (just like the tuning knob does to switch bands) and the time will appear. It may also be set that way, though I can't recall now if this nullifies the default five second timeout.

The owner's manual mentions no such "on demand clock" feature on the CD player. I'm willing to bet the CD player is a rarely seen option, especially in 1993!

There's another fun trick you can do with these radios (again, the CD player model is probably excluded). Although there are four station memory buttons, you can actually store seven stations in the memory presets. This is accomplished by following the normal procedure to set a station preset, only you press two adjacent memory buttons at once to get the "extra" presets. I'm told the "six station" memory is mentioned in Cadillac owner's manuals. The seventh preset (reached by pressing the two middle buttons in at once) appears to be totally undocumented, but it's there!

I can't yet post a link to my web page about this, which shows how to do it with illustrations!

you can now, the cutoff is 5 posts.

Krzdimond wrote:

you can now, the cutoff is 5 posts.

I just tried it again and the forum is having a different idea.

"New members are not allowed to post external links or emails for 7 days. Please contact the forum administrator for more information."

DOH! Those dasterly cunning, yet not always so evil administrators strike again. Whose been changing things up around here?

I too have a 93 except it's a RMW. I'm gonna have to try that display trick and see if it works on Ms. Roadie.

Mayhaps the problem is because you set the supposedly non existent seventh memory preset; which is not mentioned because it results in a catastrophic chain reaction to the space-time continuum. Resulting in all 1991-1993 AC Delco radio/radio-cassette players to constantly display the time. Only it's a quantum level design flaw which can only be perceived when being observed as the display of time; when in actuality History as we know it is continually being unwound in a backwards rate slowly erasing space-time as we perceived it. . . How long has this been going on? Could this explain the madness that has embraced the populace of the world on a subconscious level resulting in the errosion of moral fiber that has always propped up man?

OR

It could just be a short or crossed wire somewhere

scoffman wrote:

DOH! Those dasterly cunning, yet not always so evil administrators strike again. Whose been changing things up around here?

I'm just thinking that someone should know that the system has Other Ideas. Other than that, I'm just "this guy" who happens to have finally found a nice B-body wagon.

Ms. Roadie should definitely display a clock (why do I want to say "how rude!" here? ) if you press the volume knob with the key off.

scoffman wrote:

Mayhaps the problem is because you set the supposedly non existent seventh memory preset; which is not mentioned because it results in a catastrophic chain reaction to the space-time continuum. Resulting in all 1991-1993 AC Delco radio/radio-cassette players to constantly display the time. Only it's a quantum level design flaw which can only be perceived when being observed as the display of time; when in actuality History as we know it is continually being unwound in a backwards rate slowly erasing space-time as we perceived it. . . How long has this been going on? Could this explain the madness that has embraced the populace of the world on a subconscious level resulting in the errosion of moral fiber that has always propped up man?

Rats. It'd be the luck, wouldn't it. Funny thing is, my 88 Buick LeSabre and 89 Buick Electra let me get away with it. At least so far as I know. No spontaneous black holes appeared in the garage!

History being unwound backwards you say?

That would also explain why my Shredded Wheat biscuits don't get all soggy in the milk anymore.... and I look more younger everyday!

Why today I even looked most youngest, like a new born, Didn't need to shave or get a haircut, and had to wear diapers.


edit: Nope. That ain't it. My wife says I opened a box of steel wool, wasn't wearing my glasses, I'm going bald and those were Depends, not diapers.


DAMN! Thought I was on to something here.

See what you started Shawn?This will go on for at least 3 negative hours.Dave will still be ugly
only now,the sheep will chase him instead of him chasing them.And he will let them catch him!
And Dave you have ALWAYS worn diapers.

If it turns out to be the radio, LMK. 91-93 caprices are common in the junkyards here.

Reponses to this thread have certainly been interesting.

As it turns out, the schematic I have is for the earlier "2000" series Delco ETR. It doesn't help a whole lot due to differences in the set, especially in the display circuits (LED vs. VFD). What I was really hoping to find was someone with the good fortune to have found a later service manual or schematic for the UM6 radio. I know both to exist, but they seem to be made of Unobtainium. So, if you have an actual service manual or schematic for the UM6 set that I could borrow or buy, I would gladly cover the shipping cost and throw in something for your time and trouble.

I've got a factory vehicle service manual coming on its way. While I know it will contain little more information than how to identify, perform basic troubleshooting of and remove or replace the radio, that last bit is what I really need to know. I don't want to tear up any interior trim in the process of popping the radio out to look it over.

I'm pretty confident that the fault is local to the radio (and most probably in the circuit that enables the momentary clock display with the key off after a volume knob press). I have a few other "known working" UM6 radios to try from other cars.

I want to keep the car original, so if I have to send the set off to have it worked on, that is what I'll do. Has anyone here had experience with a Delco radio repair facility? If so, what company would you recommend? Cost is of secondary importance to the work being done right.

On the plus side, I now know that the tape deck works perfectly.

Removing the dash is pretty easy. All of the screws have a 7mm head. I have taken about 30 of them out. Screws are located along the undersideof the pad, one under the recess for the hood release, one at the lower left of the glove box.

You have to remove the steering column access panel before you pull the front off, or you will break the top two tabs that hold it in place around the column. It has two bolts on the bottom.

I have always pulled the glovebox door stop arm out of the hole and moved it to the side, but removing the glovebox door is safer, because you do not want to break the stop arm. 4 bolts under the glove box door, and it is off.

Put the wheel in the lowest position, and remove the lever from the column (difficult, very tight). Block the car, and put it in first gear.

The dash will pull off of the clips, as you make sure the top edge clears the bottom of the dash pad. The passenger's side vent is separate from the dash, held on by a separate screw, and is overlapped by the dash pad. It will break if you try to pull it off.

If the dash has been off before, the tabs for holding it to the pad will probably be crushed or broken. I used some scrap plastic, and built them up with heat, then used a small sanding drum on my dremel to shape them properly.

Removal of the radio is pretty straight forward with three screws holding it in. I have not worked on the internals of the radio/tape/CD player, so my help stops there.

Thanks for the info. I was hoping I wouldn't have to go that "deep", but it's OK. Sounds almost the same as what I had to do when I put a radio in my S10 pickup (apart from removing the glovebox door).

Is there anything in particular that can be done to avoid crushing or breaking those delicate parts? Fabrication isn't my strong suit, so it will be best if I take great pains not to break anything. I doubt the dash on this car has ever been apart.

Which lever is it that needs to be removed? The one for the tilt wheel? How does it come off? (My factory service manual is coming, but it's not scheduled to be here yet. If good, clear info is in there, I'll wait. I'm in no hurry.)

You don't have to remove the tilt lever. The bezel will come off around it. I've never removed it and I've pulled the dash apart 4-5 times.

It can be done with the lever in place, but I unscrew mine so that I do not bump it with the dash, and have the wheel try to give me a bloody nose.

Not sure how you take apart a dash but my face is nowhere near the wheel when it comes off...

Cadet57 wrote:

Not sure how you take apart a dash but my face is nowhere near the wheel when it comes off...

You'd be surprised ( and it usually comes as one when it happens) how close you come to getting your chin whacked real hard. Had my dash face off many a time, 20 if not more, and my chin got whacked afrew times along the way when the tilt wheel snaps up..

It helps to keep the car in "Low" to swing the shifter handle out of the way. The real problem I always had was the cask metal bulge that the shift lever goes into. It's hard to force the molded facing off (or back on later) around it. When I went to a floor shifter, I cut and ground that little cast metal bugger right off the column!

Well, I had a weekend at my disposal (as most of the rest of you probably also did ). Let's see what I got done on the radio removal front.

I hauled out the service manual and a copy of this thread, my tools and a few containers to store screws in. About twenty minutes later, I had the dash trim in my hands and relatively unharmed. I also did not manage to hurt myself. From the looks of things, I did break parts of the plastic tabs on the top portion of it. Given how careful I was and how slowly I worked, I can't see any way of avoiding this breakage.

Why in the world GM didn't make this thing a two part assembly I will never know. Things I learned/might point out or found interesting:

1. Getting the dash trim over the tilt wheel lever was a pain. This was the only portion of the process where I thought I'd break something.
2. There is foam around the indicator lights and dash vents. This foam has dry-rotted and will get all over anything. At least it's not as horrible as the stuff I've found in IBM PS/2s (my other hobby) in that this stuff doesn't stick to absolutely everything. I was able to just brush it away and discard it.
3. I found an interesting indicator in the left hand (as you're seated in the car to drive it) six-position indicator panel. It's a red "hazard triangle". No mention of it is made in the service manual, but there it is for light to shine through once it is out of the car. I suppose it wasn't really needed as the turn signal indicators would illuminate when the hazards are on. You might wonder why I'd point this out and to that I'd say it's an odd hobby of mine. I like looking inside display panels for unused elements, wondering what the manufacturer had in mind for them. I can only imagine that this indicator was placed for use on an exported version of the Caprice and subsequently not used/not needed. (Were these cars exported outside of North America?)
4. Removing the glovebox cover wasn't really needed, but I did it anyway.
5. I can now see how one could get a big surprise, bruised chin or a bloodied nose from the tilt steering column. If you work with your face above it and manage to trip the tilt lever with the wheel at the bottom of its travel--schnappo!--there you have it. I worked from underneath and behind the wheel, so it wasn't a problem for me.
6. My column shifter doesn't go into second or first gear. I really found this out earlier in the week when I wanted to shift down a gear to descend a long hill. I just couldn't get the shifter to move into either 2 or 1, and I didn't want to break the shifting linkage while far from home. By slamming it down, I could get it into second, which was good enough for this job. I felt kind of bad treating the old car this way, as I'm sure its previous (elderly) owners never treated it that way.

Okay, so what about the radio? Quite simply, whatever's wrong is an internal fault. I found a radio pulled from a 1990 Lumina, checked it over to make sure the wiring seemed compatible and hooked it up. The Lumina radio is sick and suffering from many ailments, but it confirmed what I wanted to know, as its clock display does turn on and off with the Caprice ignition switch. I suspect the Caprice radio was damaged when someone forgot to shut it off during a jump start. My best guess is that the time display goes on when a transistor is turned on at key-on or key off/volume knob-button press time.

I also noticed that even in its degraded state, the Lumina radio sounded better than the original. It was a lot less harsh and focused on the midrange than the UM6 this car came with. (The stock Caprice radio also exhibits some mistracking in one direction of tape travel.)

Seems to me like it's time to service the UM6. I'm not really interested in one from a junkyard and it's my intention to keep the car as original as possible. Even if another set works now, it's going to have electrolytic capacitor failures soon enough. What I want to do is fix the radio I've got. I'd do it myself, but GM felt it necessary to coat the circuit boards in a nasty yellow material that just does not come off.

Has anyone here ever done business with a facility that repairs factory Delco radios? If so, which one would you choose?

uxwbill wrote:

... (Were these cars exported outside of North America?)...

Yes. Many were shipped to the desolate, frozen northern village of Canadia. They have strange customs, and are communists.

uxwbill wrote:

... My column shifter doesn't go into second or first gear. I really found this out earlier in the week when I wanted to shift down a gear to descend a long hill. I just couldn't get the shifter to move into either 2 or 1, and I didn't want to break the shifting linkage while far from home. By slamming it down, I could get it into second, which was good enough for this job. I felt kind of bad treating the old car this way, as I'm sure its previous (elderly) owners never treated it that way...

This is easy to adjust. Put the car in 'Park' and get underneath it. Loosen the (10mm?) bolt on the shift collar, and use a little pressure to push the shaft up as far as it will easily go, then re-tighten. It should get you at least an easy second, and maybe first. If you feel like it, check to see if there is any slop or wear in the nylon bushing/washer on the end of the spring. They wear too. The more wear, the sloppier the shifter-feel. As long as you're down there, slop some heavy grease on the washer.

scoffman wrote:

Mayhaps the problem is because you set the supposedly non existent seventh memory preset; which is not mentioned because it results in a catastrophic chain reaction to the space-time continuum.

Mayhaps, huh? I didn't even notice that the first time!

As it turns out, the seventh preset is mentioned in one place (that I've found so far)...and that is in the factory service manual. It explains how to set and recall it. As expected, it does not apply to the CD player model.

jimbeau wrote:

Yes. Many were shipped to the desolate, frozen northern village of Canadia. They have strange customs, and are communists.

I was referring to the North American continent as a whole, not just the US. Besides, Canada strikes me as a pretty cool place to visit or even live. Maybe someday...

jimbeau wrote:

This is easy to adjust. Put the car in 'Park' and get underneath it. Loosen the (10mm?) bolt on the shift collar, and use a little pressure to push the shaft up as far as it will easily go, then re-tighten. It should get you at least an easy second, and maybe first. If you feel like it, check to see if there is any slop or wear in the nylon bushing/washer on the end of the spring. They wear too. The more wear, the sloppier the shifter-feel. As long as you're down there, slop some heavy grease on the washer.

I should have done this when I had the car up on a lift. If I put enough miles on it to warrant an oil change before the old wagon goes into winter hibernation, I'll see about making the adjustment at that point. I wouldn't say that the shifter feels at all sloppy in Park thru Drive, but it does make a noise suggesting that it is dry and in need of lubrication when operated.

It's so easy to do, that it's laughable.
.
Regarding Canadia:: Do NOT take it lightly. They are a strange breed of people, with slim, attractive women,
but they are hazardous to your health.
.

Those are NOT Canadians in that photo.

I don't see a single hockey stick, piece of back bacon or bottle of Labatts in that Picture.

That looks like people from the Vermont Albino Society.

The B-cars were also exported to the Middle East, and parts of Europe. There's a member here from Poland (I believe) with a Euro-spec wagon.