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1994 Accord - Electrical Problem - The Case of the Dissappearing Car Talk Show

I bought my 1994 Accord LX new and am happy with it and the ~240K miles it has. Recently a very odd problem has emerged that is annoying that and I’m wondering if it could be dangerous.

Problem:

The power to the radio cuts off now and then but only for a second. This of course always happens when I’m intensely listening to something like Car Talk. I first noticed it about 3 months ago while driving on the highway… whenever I tapped my brake peddle the radio would cut out. NOW the problem happens whenever it wants to…sometimes I go days without any problem, other times I can get a string of 5-10 failures right in a row and then it’s “ok”. Here’s the REALLY WEIRD thing… about 1:10 times when this happens BOTH the tachometer AND the speedometer cut out too! They drop to ZERO and then when the radio comes back on they pop back up to their proper readings… note nothing happens to the fuel or engine oil pressure gauges. The dashboard failures are what now have me worried.

What Have I done to address it?

Nothing yet, not sure what to do… I cannot intentionally recreate the problem. Last time I took it to the mechanic for something else they looked at this but they couldn’t recreate it. I’m afraid if I just ask someone to fix this it’ll either cause a lot of hours to be racked up with no result or a lot of guesswork replacements.

What do I want?

Has anyone else experienced this? If so how can it be fixed? Otherwise what steps or approaches do you think I should take to try to diagnose/fix this? Help?!?

Thank you,

Joe

Sorry for the TYPOS… DISAPPEARING should be with one “S” not two… I’m sure there are others!

When the radio drops out, does it act like it has been totally switched off?
It may be a bad ground or power somewhere as that is what all those parts have in common. Intermittents can be hard to find. Often you have to rig something up to see if it makes a difference.

The less risky to check would be to bridge ground. It would involve gaining access to the radio’s back so you may need to take covers off and stuff like that.
Once you’ve gained access to the radio’s back, you could get a clip lead from Radioshack and hook it from a metal piece on the radio to a larger metal piece in the general vicinity, it bridging whatever possible bad connection you may have. Then drive around with it and see if it has gone away. If it hasn’t, it may be power.

Thank you for this advice RemcoW. I’m not very handy so this would be something I’d get help on.

Yes, when the radio drops out it’s like it was turned off and then on again.

I’m still perplexed and concerned that the same problem seems to be impacting the tachometer and speedometer which makes me think it could be something further into the electric circuitry beyond the radio.

Yes, it does sound that way.
The tach, speedo and radio have very little in common, besides power and ground. That’s where I’d start looking. If you have a friend that’s a bit more handy, perhaps he can give you a hand.

If you can, remove the fuse block and carefully examine its back side for signs of a bad connection (melted plastic)…Dashboard problems usually can be traced to bad grounds or a bad hot feed to a circuit board. Tracking them down can be tedious, time-consuming and expensive…

The only thing that the radio and the speedometer and tach have in common is the number 18 fuse located in the underhood fuse box, but this is the fuse to the ignition switch, so if the problem were there, then the gas and temp gauge would also go to zero and the engine would cut out. If you are not loosing your presets, then that rules out a battery connection or main fuse relay or engine to chassis ground.

Honda uses redundant grounds, two per circuit, and these items are on separate ground circuits, so if it was a ground problem, 4 grounds would have to fail simultaneously.

The brake lights are on a separate circuit as well so I don’t see any connection other than the g forces from deceleration. You either have more problems than you are aware of or you have separate, intermittent problems that occur at exactly the same time, what are the odds.

If you love the car, and I can see why you would, they are a great car, then a new sound system would not be out of order. How ever, the radio gets its power from the cigarette lighter relay so a new relay may solve that problem. I don’t know how the other problems are related, but maybe if you stop the radio from cutting out, the other problems might be resolved.

@Keith, yeah there’s usually more than one way that leads to ground but they often are meant to carry different currents.
If one ground connection fails, it finds its way through another connection.
Depending on what that connection was meant for, you have more current going through it which causes a larger voltage drop across that connection. If it happens to feed anything that communicates to something else or reads something from halfway across the car (they all do now) and that current is large enough, you get ground bounce and logic levels are misinterpreted. Bad grounds can play havoc with a system.
I bet that’s where most the weird problems emanate from.

I’m not saying ground is where it is at but it certainly can be.

Yeah I’d check and clean up the ground wire attachments. Just for future reference, peddle is what you need a license for to sell encyclopedias, but pedal is what you push to apply the brakes. My wife is an English teacher.

So one can be up some infamous creek without a pedal and it not make much difference?

You’d still be without an effective paddle.

If this is a ground issue as RemcoW suggests, the only ground that I can see that would only affect these three items and not everything else is the engine to chassis ground. Honda uses several of these, they are flat, braided straps from locations around the engine to locations on the body under the hood. One of them goes around the front motor mount.

The reason I speculate this is that the tach gets its signal input from the ignition module and the speedometer gets its signal input from the VSS on the transmission. The grounds for the signal inputs would be on the engine/transmission. The power grounds for the instrument panel and for the radio are located under the dash, they are separate grounds and each one of them has two separate ground points.

I would suggest that the OP start by tapping the cigarette lighter relay and see if that duplicates the symptoms, with the radio at least. Still not seeing a connection to the tach/speedo that does not affect a lot of other things too.

The cigarette lighter relay is next to the radio behind the center console. The center console is easy to remove. Open the storage box cover and remove the panel in the bottom, take out the two screws and remove the rear section.

Put your key into the slot next to the stick shift and move the stick shift lever into the 1 spot, be sure the hand brake is set. Pull out the cup holder and the ashtray. Remove the screws under the cup holder, at the back of the console and the one behind the ash tray. Then lift the forward part of the center console out of the way.

The cigarette lighter relay is to the right (passenger side) of the radio.

A quick check would be to plug something into the cigarette lighter that has an indicator light. The when the radio cuts out, see if the indicator light also cuts out. I didn’t ask this, but does the radio display cutout when the radio cuts out? If it doesn’t, then the problem is completely different.

After looking over the posts about this trouble I tend to think the trouble is with the power side rather than the ground side. You could run an extra ground from the battery to the dash area to see if that changes things. If it does then you need to check the grounding connections to the chassis. It might be a good thing just to go ahead and clean them anyways.

If the trouble is with the power side you might be able to locate the trouble spot by using a screwdriver handle to tap on suspected wire connections under the dash and hood areas along with the fuse panels and ignition switch. A tap in the right place usually points out this kind of trouble.

I want to thank everyone for their advice and especially for the spelling/word error flag… my bad.

It looks like I have enough here to play around. I have a friendly mechanic (who doesn’t with a car this old) and I’ll run these suggestions by him to see what he thinks and to find out if he would mind fiddling with it for me.

I need this car to go at least 1 more year, 2 if I can get it; my son will be 17 then and this will be his “first” “practice” car. :wink: Too old and scary to impress his friends but operational enough to get him somewhere nearby.

I’d keep the car forever but my wife gives me grief because it is soooo old she’s afraid something I might actually need might fall off when I’m on the highway.

Thank you1

Joe