Tail light head scratcher

[TLGPE]

A week or so ago I asked if anyone had any insight about my tail lights not working even though the headlights do. Several responders made good suggestions and I went through everything I could come up with.

End result is I decided it MUST be the switch itself. I ordered a new switch from Spartan; about $45 with shipping. Got it in and it an exact fit and works EXACTLY like the old one. Headlights work, but not the tail lights or dash lights.

I'm baffled. There several relays for "clearance lights", which I'm told includes the tail lights. All of the relays work perfectly; I took each one out, checked the operation, greased the terminals and put them back.

The ONLY connection that changes when the switch is pulled is that power is applied to the headlight. The other three wires on the switch do not get power, nor does continuity switch to any other terminal. I absolutely do not get it.

I think I have the right wiring diagram, but it is just a huge mess with no labeling to help find anything. Bummer!

Anyone have any more suggestion?

If I had a wit, I would be at the end of it.

Tom

[Winemaker2]

Ask Newmar to email you the wiring schematic for the lights and back track to see where you have / don't have power.

["007"]

Do you have battery at any of the relay contacts going out and a common ground at light strips of lights, can run temp ground wire from battery ground.
Is there ground coming from light switch contact when operating the switch?
You should have battery to each light bulb its looking for its ground.

[mikelm48]

I assume you checked the fuses located outside under the drivers seat and behind the rear wheel on the passenger side.

[ralphie]

If it's not a fuse or bulbs, it's almost always a bad ground in 12v wiring. You should be able to run a test wire from each lamp to a known ground. Otherwise, pull each light and track the ground wires forward till you locate the bad connection.

[CoachC]

Hello Tom,
If all other functions in the taillight assembly(s) work, grounding should be good at that end. If not I would continue looking there. (Apologies if I missed that info in your previous thread)
I have tried to locate the light switch on the schematics with no success so far. Is there more than 1 "power out" pole on the switch? Unless your new switch is defective also it makes no sense that you are getting power to the switch but it's not being distributed to the tail lights.
Our electrical systems should be very similar so I'm pretty curious as to the problem.
Unless someone has changed or messed with wiring they should be color coded and labeled by circuit I believe. Identifying connectors or wiring block terminals in that circuit may be crucial to find the problem. I'll continue to search the schematics I have.

Good luck.

[CoachC]

Tom,
Do your side, front and rear marker lights come on with the headlights?

[CoachC]

Ok, I'm no electrician and not very good with schematics. I did find the switch and circuits for the lights.
I know you checked relays but you may want to double check both the relay and the 20A fuse for the marker lights. I believe these are located in the front power distribution center. (Outside bay under driver's seat) It appears the taillights would be powered through that circuit.

[l1v3fr33ord1]

TGLPE-

Here are the Spartan schematics for your coach. The tail light circuits are shown on sheets 82 and 83.

http://www.spartanchassis.com/cps/lo...8514623750.pdf

"CoachC" apparently has the same schematics, as he is guiding you down the correct path (fuse, relay, asking if other lights tied to the same circuit are working).

[TLGPE]

Good morning gang,

Again, thanks for the responses, it's greatly appreciated.

I do have the Spartan schematic, all 100 or so pages, broken up in bite sized pieces. Very difficult to follow, but professionally done. The info is there, just hard to understand. (That's code for too lazy to dig in and get it done). Last night I dug in and found a couple of clues, which allowed me to sift through the first 84 pages of PDF screens. There, on page 84 it shows that the brown wire (I knew that) is feed by a relay in the front (page 83). That relay leads to a 20 amp fuse in the rear of the coach. The fuse is directly wired to the battery back in the battery bay. (I think).

I'll get over there again this morning and try to find that fuse and find out why there is no power on it.

I think I can understand why they ran a separate wire for the headlights and the "clearance" lights; as someone here (thanks) has mentioned, they power the headlights through an automatic reset circuit breaker. The tail lights, etc. go through a fuse. OK, that's the designer's choice. Move on.

The reason I thought that the switch was bad is that only the headlights changed when I pulled the switch. When I look at the schematic, it shows that the switch also connects two other unrelated contacts, one of which gets power from that wire from the 20A fuse and the other goes to my little brown wire at the tail lights.

Clear as mud, but if I can find that rear fuse and restore power there, I should be good to go.

I shall return later today with an update.

Tom

[TLGPE]

JOY TO THE WORLD!

Well, I found the fuse, right where the said it would be............and it was fine. Back to the schematic.

After a while, some of the stuff made sense and some did not, but the schematic shows the light relays as being in the rear areas of the coach, but I can see them in the lower compartment by the driver. Looked there again and found the wire I needed (SP008) coming out of the large bundle from somewhere else. It had no power, so I removed the fuse panel and found it, looked for that fuse, and there it was. These are labeled "marker lights". THAT fuse was blown. New fuse, and my lights work.

I did check the fuses, but not the one for markers. All that, just for that.

Thank you for all who looked, responded, and tried to help. I guess some people can't he helped,,,,,,,,,,,,,

Tom

[Dutch Star Don]

"TLGPE".....It's so nice when you can solve an aggravating head scratcher.

["007"]

Good for you, now that you found it this link might have help also mid way down link besides all the fusing are the dash relays.

[CoachC]

Hurray!

Way to persevere. Issue solved and you gained a little more knowledge about your coach.
Store that away in your memory banks. As good as money!

Cheers