Reading Lamp / Map Light behind Driver's Seat

JimNeel · 07-02-2019, 04:03 PM

Does anybody know how to go about troubleshooting
the small lamp just over the driver's left shoulder? I've
seen it referred to as a Reading Lamp and a Map Light.
Mine is not working. Checked the wiring at the light and
I do not have 12 volts. The passenger side light is working
just fine. I have no idea where to start with this.

2002 Itasca Sunova 30b

Thank you

SLOweather · 07-02-2019, 04:21 PM

In our Sunstar, that light is controlled by the dash lights dimmer. That is a thumb wheel on the dash to the left of the steering wheel. Thumb it UP all the way and you should feel a detent. That's the switch for that light.

Then, if it doesn't light, there is a push on push off switch on the reading light itself. Push that. Both switches need to be ON for the light to illuminate. The ignition switch does not have to be on.

JimNeel · 07-02-2019, 05:23 PM

I may have tried that, but then again, I tried many
things. I will give this a shot tonight.

Thank you
-jim

SLOweather · 07-02-2019, 06:04 PM

You have a 2002 Sunova. I doubt that the light is LED like our Sunstar. The 3rd option is to check the bulb, if it's not LED.

If you were a techy, I would say that the truth table for this lamp has several states, only one of which makes it light:

Dash switch ON

Lamp switch ON
Bulb GOOD

and there is a fourth one

Fuse GOOD

presupposing that 12 VDC is present

If I were doing this, I would
1A) check the lamp for LED or incandescent, check the bulb if incandescent

1) run the dimmer switch up past the detent
2) turn the ignition ON
3) try the switch on the lamp

If it lights, turn the ignition switch OFF and see if it still is lit.

JimNeel · 07-03-2019, 06:10 PM

OK I have results.

I tried everything and NO JOY.
Dimmer switch: dims the dash lights but still

no 12v when the dimmer is turned all the way
up and clicked on.
Engine turned on, engine off, generator on, gen off.
I tried everything but still never get 12v at the light.

I don't know which fuse, nor where to find it, operates
this light.

Bulb has been swapped out with another that is

working. Bulb from the bad light put into a known
working light and it works fine.

Could the dimmer switch be bad even though it dims?
Anybody know where the fuse is for this light?
perhaps even the fuse number. These Winnies have
so many damn fuse blocks and relays and they're

located all over the place.

l1v3fr33ord1 · 07-04-2019, 05:12 AM

JimNeel-

1) Ford or Workhorse chassis under your coach?
2) What is the GVWR (Gross Vehicle Weight Rating) of the chassis?
3) Can you provide a picture of the fuse panel that is under the flip-up dash panel? (see pages 95 and 9-6 of your coach's owner's manual, link here)

If your coach has an 18,000-pound GVWR Workhorse chassis, check the 20A fuse bottom row, third from the right. It should be labeled "CTSY" on the block at that location.

dickb46 · 07-04-2019, 07:56 AM

This is probably out to lunch but...
I have a 2003 Journey, to turn on that light I turn the actual headlight knob (like you would on an old car to turn on the dome light)

JimNeel · 07-05-2019, 06:31 PM

As you can see in the attachment, the fuse
that l1v3fr33ord1 refers to in his post is NOT

there. Also, I can't find the labels for this fuse
block anywhere. It's not in the pages l1v3fr33ord1
mentioned.

24+ years of electronics and electronics

troubleshooting and I've never had this hard

of a time tracing a simple wire for a light.

Hubba

l1v3fr33ord1 · 07-05-2019, 07:22 PM

JimNeel-

That is a Ford fuse block. So, the fuse I pointed out (in advance of knowing what chassis is under your coach) is incorrect.

Based on the diagrams for your coach (link here), I would examine the 20A fuse #16 on the Ford fuse block pictured. If that fuse is dead, you would also not be able to run the dash radio from the chassis battery. Fuse #16 is third row, second from the right in the picture.

The owner's manual for your coach's Ford F-53 chassis is here. The Passenger Compartment Fuse Panel is covered on pages 41 through 44.

Let us know what you find with fuse #16.

JimNeel · 07-07-2019, 02:52 PM

Fuse 16 is alive and well. Not the problem.
On to "Plan K"

l1v3fr33ord1 · 07-08-2019, 05:21 AM

JimNeel-

The "dome light" is shown on these two drawings:

Automotive Wiring Diagram (Sheet 2, Zone A-14)
Front End Wiring Installation (Sheet 1, Zone D-5, Sheet 3, Zone D-1)
Note: For this drawing set, you want details labeled "16H," which are for the Ford chassis

The relevant circuits for the dome light are "MK" (12V) and "MN" (ground). The "secret decoder ring" for circuit IDs is the Wiring Identification Guide (link here).

If I were troubleshooting, at this stage I'd test at the headlight switch. I'd first see if the instrument panel dims when I run the wheel up and down. Then, I'd test (again- I know you've done this) the dome light function by rotating the dimmer up beyond "brightest" to the detent setting. If no dome (map) light, I'd check for 12V at the rear of the dimmer with the wheel in the detent and non-detent positions. That should tell you if the problem is upstream, inside, or downstream of the headlight switch.

I will send you a private message with some additional information.

tderonne · 07-08-2019, 08:07 PM

I didn't look at your wiring diagrams, but I suspect yours is wired similarly to my '04 F53 Adventurer. ( Which has a second switch to turn the light on, since it has a driver's door.)

Winnebago wired the domelight circuit wrong. Ford provides a relay to wire to the domelight ground to. Winnebago wired the domelight directly to the dimmer switch. My switch burned out under warranty. When it burned out again, I looked at the diagrams and figured it out. It took quite a bit or rewiring to get it wired right. It's been many years, I forget the exact details.

Another possible solution might be swapping to a lower current drawing LED bulb. And then replace the headlight switch assembly. Or just add a properly rated switch someplace.

JimNeel · 07-10-2019, 09:07 PM

So, today I tracked down the ORG/GRN wire into
the headlight switch assembly. I have 12v on that
wire. I have not found the BRN/RED wire yet.
By the looks of it, it should have a tag reading
"Battery Feed". Something tells me that I found
a wire at some point that said "Battery Feed"
and was not connected to anything. Further
investigation is needed.

I am confused about the ORG/GRN wire. According
to the drawing, it says "Interior Lamp Switch (GND)"
but I have a +12v on that wire where it goes into the
switch assembly. Maybe when I find the BRN/RED
wire it might make more sense.

JimNeel · 07-10-2019, 09:14 PM

Quote:

So, today I tracked down the ORG/GRN wire into
the headlight switch assembly. I have 12v on that
wire. I have not found the BRN/RED wire yet.
By the looks of it, it should have a tag reading
"Battery Feed". Something tells me that I found
a wire at some point that said "Battery Feed"
and was not connected to anything. Further
investigation is needed.

I am confused about the ORG/GRN wire. According
to the drawing, it says "Interior Lamp Switch (GND)"
but I have a +12v on that wire where it goes into the
switch assembly. Maybe when I find the BRN/RED
wire it might make more sense.

TDERRONE...
Adding a new switch, running new wires in a pc of
wiremold along the floor and up to the light is
looking more and more likely. It just might happen
this way. Thank you for the advice!

navnaz · 07-10-2019, 09:21 PM

Did you try rotating the rotating knob on the dash that dims/brightens the dash/gages lights. If you rotate it all the way, you’ll feel it click into a detent, the drivers reading light should come on.

ezdavie · 07-11-2019, 05:50 AM

My 03 Adventure - Open driver's door! Light will come on!!

skyking · 07-11-2019, 07:14 AM

As mentioned above, don't forget that the wiring harnesses are complex and people make mistakes. I had found a brass connector that was placed in the wrong hole of a plastic socket assembly, that caused my house batteries to not charge while driving. Once found, an easy fix.
The reading light switch, on your dimmer control, will be a separate "on-off" contact, with a connector that is separate from the dimmer portion. Are you able to check for 12v there and verify its connector is in the right place?
Richard