My dash board instrument lights are out.

I believe there are three bulbs and think it odd they all decided to go out at once.

Does anyone know if these bulbs are wired like x-mas tree lights where if one goes out it kills the other two?

I'm going to check the rheostat now.
The fuses all look to be in good order though I will pull and clean the suspect fuse ... or all of them.


--
1988 244 DL; B230F; LH-2.2; Manual 5-speed (M47)

Now I'm stumped.??!!

I pulled and tested the instrument bulbs. They light off of the battery.
(Note: I can only find two bulbs though the 1987 wiring diagram shows 3. These are screw-in-the-back of the instrument cluster bulb-sockets each very near the signal arrows. I tested the adjacent signal with the bulb socket removed to confirm the bulb was not for the signal.

I replaced fuses #15 and 16. No change.

I pulled the brown and red/white wires off the back of the instrument panel dinner switch (rheostat) and wired them together. NOTHING!! No change.

*****

Would the reverse lights and right rear running light play into this?
I replaced the back-up lights fuse too.
I hope this does not devolve to electrical gremlins.
--
1988 244 DL; B230F; LH-2.2; Manual 5-speed (M47)

Still stumped ...

Clarifications:
For some reason the reverse lights were OFF but have come back ON.

The right side, front and rear, tail lights (parking/running lights) ARE Out.
I was distracted by a bad bulb in the right rear.

I spent time looking at the '88s wiring diagram and it tells me #16 IS the fuse for the instrument lights and the right side front and rear tail lights.

I reconnected the panel light dimmer switch.
Starting from scratch ... I find the "new" #16 fuse is blown (!!).
A second new fuse holds up to a test but still no instrument lights.

I checked voltage across the #16 fuse contacts and get 11.27 volts DC.

So
IF I have power through the fuse ...
and the panel light dimmer is taken out of the line and I still get not panel or tail lights ...
(I need to do this again and check back to the fuse to make sure it is still in tact (?)}
THEN I am looking at a break somewhere between the fuse and the panel light dimmer ... does that seem correct?

Seems to me if there is 11.27 V across #16 ... a short in the line would blow the fuse ... and if the line was broken there would not be current across #16 ... is that correct?

*****
So is my next step to pull the fuse box, clean and dielectric grease all contacts?

I do not like driving at night with my tactical red head lamp.

--
1988 244 DL; B230F; LH-2.2; Manual 5-speed (M47)

Hello again!

I need to ask some basic questions, since I know you have a voltmeter.

First, the battery voltage seems rather low since it is should be coming from a 12.6 plus on a charged battery. If you had just ran the engine, the residual charge should be temporarily up to around 13.2+.
A running Charging voltage should be 13.2 to 14.2 "across" the positive and negative terminals.

If you run your leads in "parallel" to the battery cables you need to see 0.00 volts, with something turned on in the car or you have rotten connections within your main cables. There are two ground cables. One to the engine and one directly to the cars body!

The next question is how are you measuring for voltage "across" the fuse?

Are you putting the leads on each end of the fuse at the same time or going from one end or each end separately with one lead and putting the other lead to clean metal body part of the car as a ground point.

If the circuit is energized, measuring "across" the ends of a fuse, that is burnt or the connection is bad, you should see battery voltage.
If the fuse is "good" you will see "zero" voltage as the meter is NOT "across" the batteries potential or voltage. You are on the same side, like you were when checking for bad cables out at the battery.

When ever there is a difference in potential or voltage there is a resistance in the circuit.
You are only allowed up to 0.02 volt for meter error or normal wire lengths in a car.
For every few hundredths of voltage there is an exponential amount of resistance.

It's a better way of defining issues of bad connections in or with a problem circuit.
You see, those electrons, the power has to leave from the negative post to travel throughout the cars body.
Just think about all the ground points! Each is a possiblity of going bad with a rusting steel or corroded noble metal attachment with those, being possibly, only "plated" nowadays!

Grounds are half of all the cars circuits and unfortunately gets ignored as not being "as" important.
Nature works very silently and humans break and wear things out.
There is No guessing, where we want to look first!

I would like to see you get a higher Battery voltage reading throughout the car!
Also get Zero's, when you expect them and know why. It would be a big path finder when Hunting!

I need to know if or how you understand what a voltmeter is telling you. Since we "all" can not see electricity, unless it's a spark, a high resistance area is just as hard to see.
A low resistance area can show itself as Burnt wire or fuse! These do not last very long. That's why they call them a short! (:) Just kidding!

A drain, now that, is another issue and might be a reason for your low voltage reading!
Lights that are dim and the smaller they are will look out! Starting with batteries not showing their voltage or STAYING not fully charged are all possibilities.

That 11.27 volts is screaming out, "There is a problem!"

Since I cannot see you using the meter it make it difficult to understand what is happening from my armchair! (:-)
You have too many things "interrelated" for most of us to say " Oh, go here and clean this or replace that!"

If and when I come across this type of perplexity, I back up to the power supply and breakdown things, step by step, going outwards and look for the proper messages coming back on my meter!

So to help you, this is where I'm stuck. I don't have the experience of what you are experiencing, to do the big, OH!

I will say, cleaning anything and making it "squared away" is very good thinking, to find your problem! The car had aged in who know what kind of environment and how many other previous owners imparting their personalities!

I'm still here to help, as the others, who might have a "OH" for you!

Phil

machine man,

I've gone from confused to confounded.

The instrument lights came back ON. (?)
Fuse #16 is holding for the present.

I can only guess that pulling the spade connectors off the dimmer switch and reinstalling them "cleaned" something. Really wild guess.

The 11.27 volt was across the fuse clips, with the fuse removed, and circuit energized.

I heard from someone else to look into the battery voltage since like yourself, and myself, I thought it should be 12+v. I'll let the car sit all day before I check across the battery terminals.

I will need to read your post more closely to work out the electrical testing.

Thank you
--
1988 244 DL; B230F; LH-2.2; Manual 5-speed (M47)

... Correction ...

The instrument "lights" did not come back ON.
The passenger side bulb came back ON.
That's good. I can see the speedometer, temp and fuel gauges.

I have pulled and checked the driver's side bulb again and it still works off of the battery.

So it has to be something in the contact with the cluster board.
(?)

I have fiddled with the socket a couple of times.
Once the bulb seemed pushed into the socket so I pulled it back out and tested it. The bulb still worked.
I tried to see if there is something that acts as a stop on the board and that seems to be the case. There looks to be only one depth the socket can seat to. So no idea how the bulb got pushed in further.

Pulling the cluster and disassembling the board is going to take me to my unhappy place.
Is dielectric grease in order first?
--
1988 244 DL; B230F; LH-2.2; Manual 5-speed (M47)

Hi,

So you are saying one of the instrument cluster face lamps came back on but the one on the drivers side did not. You checked the bulb to a battery and it lights but not while plugged into the board.

Did you reverse the sockets and their bulbs from one side to the otherside?

I would do this to see if that same socket does not work in the right side on the passengers side.

If it does then it's not a problem with the socket or the bulb in either case, but the circuit trace around the left side divers hole.
It maybe be bad or does not have power or a ground path. Those bulbs are in parallel with each other across the power supply. So if one is getting power they both should.

When it comes to any traces on these circuit boards, of the cluster or the taillights, I use a pencil eraser and scrub them until shinier. The old typewriter print pencil erasers worked the best and faster. They have just a wee bit of grit and scruff to them.

I also tweak the tabs, outwards toward the board, on the sockets just a bit to make sure there is some extra tension against the board. This helps hold the circuit board to one side of the groove in the socket.
I once thought that they could be put in backwards. There is no reason for it.

But if the helix were made short of a full 45 or 90 degrees of turn, it could be possible to put them in backwards or not align to a trace. I have never caught that to be true but you never know with light bulb manufacturing across so many vendors!

As far as the bulb getting pushed back farther into socket, I think some are made at the factory.
These types should be resistance welded internal at the base and are not replaceable.
I don't remember exactly. But I think they were Halogen, on the last models years.
Or, I have run into some that were replaced, I don't know for sure.

These are not found in all cars but in both cases the panel lights glass parts are larger than the other bulbs throughout the cluster.
Some of those, plain "Jane," ones are replaceable.
Those also have four lightweight contacts, side gripping, clips down in there.

It all depends on the years and the " subject to change without notice" fine print in a manufactures declarations.

Just a very light or thin film of any anti corrosion "salve" helps conduct those low milliamperes of currents around.
Same goes for those large plugs pins, as they need some loving too!

Phil

Machine Man,

Since the car is operational testing has been pushed to a back burner.

I did not swap sockets but did test the bulb in the socket by powering it from the board contacts.

Will you be more specific about tweaking the tabs on the socket?
I can only imagine that means squeezing them a bit tighter (?).

I still have not back tracked the low voltage at the #16 fuse to the battery which was at !2+ volts.

*****
NEW AND IMPROVED ...
the left turn signal lamp went out on the instrument panel last weekend. The front and rear signal lamps still work but no flashing on the instrument cluster.

This is a bulb an inch or so from the driver's side instrument cluster light that is out.

*****
It looks more and more like a compete removal of the cluster is going to be in order.

Any warnings, dos and/or don'ts?

--
1988 244 DL; B230F; LH-2.2; Manual 5-speed (M47)

Hi Thomas,

Yes oh boy O howdy do I know about back burners. I very aware of them, especially, the one that gets the portion just below my lower back, when I put things off way too long! (-:)

The part about tweaking the tabs is something that I try to do to increase the tension pressure of the contact towards the clusters circuit trace of copper.
I do not have a cluster available to see if the turn signal indicator bulbs are "All that" tweak-able.

I just try to get or make sure that the contact is definitely pushing down onto the trace. It also makes for a tighter socket in the hole.
They are miniature when compare to say the taillights of a sedan.

Another thing you can try is putting some drops of lemon juice on the trace and rub it with a pencil eraser. It's a mild citric acid to help buffer off a black oxide that can develop on copper.
It helps not to be too abrasive with the amount of copper available as a film.
I forgot to mention that earlier.

I'm not familiar with what fuse 16 does but only two volts on there does not sound great if you are suppose to get 12 volts.

I don't know how you had the voltmeter hooked up,as you might be reading a voltage drop due to a proper load on the circuit. You could have been reading in-line on one side of the circuit and not across it.

Across it means from a good ground to the positive side of the battery direction back only.
Like checking for battery supply at the battery posts. 12.50-65v plus on a fully charged or higher after an alternator shut down which can be as high as 14.2

You expect to see 12.6 or very close to it, everywhere in the car, normally?

That is, unless you are on the opposite side of the load or resistance, aka corrosion.
If the load was NOT on and you were reading that, then, you have a very serious resistance on the circuit. Big bad corrosion somewhere.

Anything over 0.02 on a "same side" reading can be considered a bad ground or positive side connection circuit.

Number 16 is the bottom of the fuse panel and closest to the floorboard.
Feet bring in wet shoes and the door jamb is a cold area.
Moisture that has "heat in it" becomes a "vapor" and that heat seeks the cold, wherever it is and will travel to the coldest point in a car.

Floorboards stay cold and so does the trunk. Let's not forget that big hunk of glass appropriately named a "foggy windshield!
Not many cars have the roof rust out from the inside.


You would be wise to service the fuse panel from top to bottom. Clean everything contact and terminal wise before winter.
Use your favorite dielectric ointment or just a film of grease is good.

I live on the west coast and I still spray a "very very light" film of LPS "1" up and down across everything in there once a year.
The evaporation of the spray puts up a barrier in the immediate vicinity of the wiring behind the plastic door.

It's just a thing I do.

Phil

Just for info, and I have not tackled mine yet. '92 245.

Same issue... no lights at cluster. I do note that I have some kind of issue at the gear selector... when I shift it to park, quite often it will try to die. Also, at times the shifter will not release from park.
Plus there are times my rear window defrost will come on... on its own, and can't be turned off until it has gone through it designed time function.

Very bad low idle issue as well, and I am pretty sure all these things are related. Just gotta find the time to get them worked on.

I wish you well!
--
"Do you think that's air you're breathing now'? (The Matrix 1999) '94 940T (463K+), 92 245 (300K+), 90 740 (148k)

I understand what you are saying!

This stuff involved here just doesn't magically show up in the brain.

I was trying to say in my post, that the low voltage reading is "yelling that there is a resistance," in the circuits or something is drawing it down along the way.

The meter can lead you there, if you blink and think about what it's showing.
If this was very easy, everyone could do it at birth!

It's not that hard once you understand, the concept that putting the meter along the sides (parallel) of a circuit you will get a zero reading, even though you know it is hooked up to the power supply.
If you put the leads on the fuses ends and the circuit is "on" it will show zero if it's a good fuse and a connected circuit the reading will be zero.

If the fuse is blown or circuit not connected it will show a reading supply voltage. You are across the circuit. Just like when you read the battery's + & - posts.

I use this method, in high voltage AC panels, with the power on!
I can check the fuses without physically pulling them and using an ohmmeter to checking for continuity.
I open a panel with only One hand! The other hand is holding my voltmeter!

Big time saver and it's safer, believe it or not?

If you ever had a switch or breaker fail to turn off, you will quickly understand why, I always try to leave my meter on a voltage setting range even when off!
It saves meters and reduces an eye opening or closing surprise!

Tools help you do work and are the extensions of one's hands. A V/O Meter are your eyes!
That's why the leads are rated at 600 volts! The main reason why not to miss treat them too!


It is when the voltmeter is applied across the circuit it shows a reading. But both uses of the leads, are giving you a reading every time, unless the power is "truly off." Then is it not?

That's what can confuse any person, not in a routine habit of using a voltmeter and invokes the brain with some diagrams helps to not to get things so scrambled.

Just from the far side of things, that's where I'm standing, I think you have an intact car but have some bad connections. That's why I said the idea looking into the fuse panel would be a good place to start.
The Battery cables, Fuse panels and all grounds might fix this and future problems.

Your statement about the lights came on, didn't surprise me!

You have a gremlin on its cusps!

Keep going, you are doing a great job!

Phil

machine man,

Still no further work on the instrument lights and that seems to have paid off for one bulb.

I was transporting some trim on my luggage rack and it was shifting. I pulled over, put on the hazard lights, adjusted the load and drove off.

A few miles on I see I have left the hazard lights ON and ... the left turn arrow is working.

This revival of the turn signal arrow did not bring the left side instrument cluster bulb with it.

It has been several days and the left turn arrow on the dash is still working normally.

I am thinking something has crawled into and on the cluster circuit board causing a short. Maybe if I wait long enough it will dry out and flake off
... wishful thinking for when work is not forthcoming.

--
1988 244 DL; B230F; LH-2.2; Manual 5-speed (M47)

The short is probably at the rear ashtray lamp like it is in 94.27% of the other posts asking why fuse 16 blows. I pointed that out in a previous reply, but it was probably too subtle.
--
Art Benstein near Baltimore

It is possible to lead a cow upstairs but not down. Guess they can go one way but not the udder.

Hi Art!

For lack of udder words, I think you might be "statistically" correct! (:-)

(:-) But you are only just over 94 percent close! Similar to political polls, the rest is a margin of error!

Phil

Phil,

You might note my facetious "94.27%" was a reference to past performance and not a probability prediction like political polling generates. The "probability" prediction was in the prediction of future results, in this case, the end answer to this thread.

As in your investments, I cannot guarantee past performance to be a predictor of future results.

Edit: The corollary to the Fuse 16 theory is the Fuse 12 (or Fuse 5 if you have a 90-93) theory. The corollary only exists if an M47 is installed. The reverse light fuse will blow until the wiring to the reverse gear switch is repaired where it runs from the top of the transmission to the shifter box.
--
Art Benstein near Baltimore

Past performance cannot guarantee future results. -Marge Innovera

Hmmm?

So the rest of the cluster works and the two bulbs burn when powered. You are not leaving much to be mysterious but it is!

You bypassed the rheostat but did it have power to it.

You might want to check a circuit off the headlight switch system since it turns on the panel lights.

The relay for the headlights is fed separately from the second position, of course separate from the parking or running lamps. The relay socket is know to have overheating issues.

Without me digging into a diagram, look to see if anything comes from the headlight position one wiring.

Just maybe there is a common terminal, that's not as common as it use to be! (:-)

I'm thinking there might be a ground wire off from the instrument cluster harness as grounds are about as common as they come!
There are a bunch that group up under the base frame that passes under the cluster. There is one screw, over by the center console, that might be a little bit loose.

Has anyone been digging around in that area lately?

What about all the other lights that Art mention in that great post?

Phil

Boy! There were a lot of "didn't knows" for me in that post Art!

Thanks,
Phil!

Funny you mention checking the rheostat...

After doing some rather involved work on my grandson's '90, he arrived with his friend to pick it up. He had his friend drive it home while he drove his mom's '93. Once home, he texted that his friend complained the instrument lighting was out.

I returned a message citing the usual checks with fuse #16 and asked whether the right hand side tail lights were working. After sending those rather involved suggestions it hit me: I had the instrument panel out, to chase the grounds in the cruise control. While it was put back carefully, I tend to put the rheostat knob back on by twisting it to the left until its "D" shaped shaft locates and seats. A second text: check the dimmer control. Problem solved. It was turned all the way down.

Anyhow on to your questions.

There are only two lights in the instrument panel. No series-connected lamps in the car, but these two are controlled by the rheostat along with those in the center console at the heater controls and switches. The automatic transmission gear selector indicator is another on this circuit. Not dimmed, but also on the same fuse is the rear ashtray lamp - a frequent cause of fuse 16 getting wiped, if you've ever had kids use that parking brake console as a step between front and back seats.

So, after checking the rheostat is turned up, take a look to see if the right hand tail lamps work. If not, start at fuse 16. If it looks blown, and not just fallen apart, check at the rear seat ash tray lamp or the shifter indicating lamp.

--
Art Benstein near Baltimore