2nd Gen Non-Engine/Transmission Light Switch Wiring Conundrum (Puzzle for those in Rio Linde)

[Ol'TrailDog]

One dark and stormy night a short while back the light switch on my 98 12v started getting warm and odoriferous warning me of the impending failure. This most likely followed installing the aluminum flatbed w/ additional lights leading to increased amperage draw through the switch. Or at least that is my diagnosis.



I decided to see if I could use the later style light switch from the 1999-2002 trucks. The switch cost me $15 and after much hassle I managed to get the connectors today for an additional $10. This afternoon I dismantled the dash bezel again, unscrewed the old light switch, donned my cheaters, pursed my lips thoughtfully, and studied the situation carefully. It happens that I am sort of shy about tackling projects that don't require a wrench or large hammer.



Here lies the conundrum. There are more wires going into the new switch than the old. I hauled out the Haynes and perused the wiring diagram, dutifully taking notes about C206 and various colored wires. I THINK that I have it figured where most of the wires will be spliced. But there are a number of orphans, e. g. the too many blues, tans, whites from nowhere, and so forth because there are 9 wires coming from the wiring harness and there are 14 wires on the 99-02 switch.



What I am in need of is a wiring genius or an everyday Joe that can look at the light switch back and tell me what color wire is coming out of the factory splice and to what color (and possibly how many wires it connects to on the connector on the back of the switch. The connector has little numbers for the holes for reference. For example bk/yl *1 means there is a black and yellow wire in connector hole #1. OK means I've found it's soul mate on the truck wiring harness.



TRUCK HARNESS WIRES: 9 wires

• 
  
  1. HEAVY GAUGE PK/GR... ..... do not know where this connects
     
  2. TN/OR... ... ... ... goes to TN at hole #7 or #14?
     
  3. BK/YL... ... ..... goes to BK/YL on connector hole #1
     
  4. PK/BL... ... ... ..... goes to PK/BL on connector hole #6
     
  5. PK/RD... ... ... ... . goes to PK/RD at connector hole #3
     
  6. GR... ... ... ... . goes to GR at connector hole #11
     
  7. BL... ... ..... goes to one of the BL at connector hole #5 or #13?
     
  8. BK/BL... ... ... ... . do not know which color wire this connects to?
     
  9. GR/WT... ... ..... do not know which color wire this connects to?
     

NEW STYLE CONNECTOR: 14 holes

• BK/YL hole #1
  
• YL/BK at hole #2
  
• PK/RD at hole #3
  
• OR/BK at hole #4
  
• BL at hole #5
  
• WT at hole #6
  
• TN at hole #7
  
• PK/BL at hole #8
  
• OR/BK at hole #9
  
• YL at hole #10
  
• GR at hole #11
  
• WT at hole #12
  
• BL at hole # 13
  
• TN at hole # 14
  

I'm assuming, hoping, some of the same colors splice into one of the truck harness wires, e. g. WT splice into one color, BL splice into one color, TN splice into one color, OR/BL splice into one color. It is intuitive where the TNs and BLs go, but not the WTs or OR/BKs.



ALTERNATIVE B: Your eyes have glazed over and you are thinking "This makes no sense whatsoever. You had take it to an automotive wiring shop where they will say, you've got the wrong light switch

 

[GAmes]

Wouldn't it be easier and faster to power all your new lights using a relay that is triggered by your headlight switch? Have you drilled some holes in the top of the vent duct just below the light switch to provide some air circulation?



It is too late to look at the FSM diagrams, but if you are sure you want to do all that cutting and splicing I'll look up what each of those wires go to tomorrow. I am assuming the wire colors remained consistant from my '97.

 

[Ol'TrailDog]

I do plan on installing a relay to run the flatbed lights. It is just that I got started on this brain storm idea??? a while back when I started suspecting the odor was from the old style light switch starting to cook.



Thank you very for the offer, but I don't really need to know what the wiring looks like from a 97, because I already know what it looks like from my 98. What I need to know is what color the wires that feed the connector pigtail wires are from the spliced wire harness junction on 99-02 trucks.

 

[fest3er]

... I decided to see if I could use the later style light switch from the 1999-2002 trucks. The switch cost me $15 and after much hassle I managed to get the connectors today for an additional $10. This afternoon I dismantled the dash bezel again, unscrewed the old light switch, donned my cheaters, pursed my lips thoughtfully, and studied the situation carefully. It happens that I am sort of shy about tackling projects that don't require a wrench or large hammer... . I'm assuming, hoping, some of the same colors splice into one of the truck harness wires, e. g. WT splice into one color, BL splice into one color, TN splice into one color, OR/BL splice into one color. It is intuitive where the TNs and BLs go, but not the WTs or OR/BKs. ...

It is good that you are reticent to tackle electrical projects; if you let the smoke out of a circuit, it'll never work again.



Your info doesn't align very well with that from my 98 12V SM:

[b]Headlamp Switch C1[/b]

[u]Cav  Circuit  Function[/u]

1 M2 20 YL Courtesy Lamps Switch Output

2 Z3 20 BK/OR Ground



[b]Headlamp Switch C2[/b]

[u]Cav  Circuit  Function[/u]

B1   A3 12 RD/WT Fused B+

B2   F33 14 PK/RD   Fused B+

B3   G26 22 LB   Key-in Ign. Switch Sense

D M3 22 PK/DB Cargo Lamp Driver

H L2 16 LG Headlamp Switch Output

I E1 18 TN Panel Lamps Dimmer Switch Signal

P L11 16 LG/BK   Flash to Pass Driver

R L7 16 BK/YL Park Lamp Switch Output

U G75 22 TN   Left Door Ajar Switch Sense

There is no Connector 206. The switch's C2 cavities are lettered, not numbered. If you need, I can post the connector diagrams.



I can't find the SM PDFs I have of newer 24V models. Someone else will have to post that info (like I did above).



Once you know the function of the new pins, you should be able to properly mate them with the old harness.

 

[Ol'TrailDog]

Thanks fest3er. The information I wrote came from the Haynes manual, e. g. the C206 connector. The numbers (1-14) come directly off the 24v connector pin holes. But you have gotten to the point much more succinctly than my ramble and you have hit on exactly what I need:



The SM PDF of the 24v headlight switch!



The Haynes manual says it covers from 1994-2001, but it certainly is missing a number of the wires on what they refer to as the C206 connector.

 

[Joe G.]

Haynes manuals are notorious for being full of errors, especially in wiring. You can get the real manual on CD for $30 here: Dodge Factory Service Manuals and Reference Books-Dodge Cummins Diesel Truck Accessories – Geno’s Garage

 

[Road Dog]

If you're have additional running lights on your flatdeck then you should use the trailer circuit which has it's own relay and fuse. Can't help with the colour coding or location of the wire on your '98.

 

[Stevem]

Light Switch

This info is from my 2001 FSM. Hope this works... first time to include an attachment.

 

[Ol'TrailDog]

Thanks a bunch for the help and the info link. With the FSM jpeg info I should be able to fry something this weekend! I have to agree about the Haynes, it was suppose to cover between 94 to 01 and no mention of the light switch changes and didn't even have the earlier models dialed in correctly.



Just to complicate matters a bit the switch had previously been replaced and the wires spliced for the new old style connector. That is why the discrepancy with fest3er's colors.



I will also plan on both LEDs for the running lights and a relay or tapping the trailer circuit, cuz I've had enough fun for one project.

 

[Joe G.]

I installed a relay to take the current load off the headlight switch in my '95. You might want to consider doing that because the switch is barely adequate for the job without any additional lights.

 

[WilsonF]

If you put relays in for your headlights it will take a huge load off the switch and make the HL brighter, did mine years ago big improvement.

Daniel Stern Lighting Consultancy and Supply
MadElectrical.com - Electrical Tech

Floyd

 

[Ol'TrailDog]

Thanks WilsonF for the links. Perhaps even I can follow the info and get the relay installed. I'm woefully ignorant about wiring circuitry, but I hate parting with money to pay someone else to do something that I reckon I should be able to figure out even more. Take this project: installing a 24v light switch to replace the standard 12v push-pull light switch that I've had to replace on several trucks. The 24v model has that nifty aluminum cooling tower that the 12v model lacks. I call it an experiment, heck it's only a $10K truck.