J1708 or J1939 in Tradewinds?

[MICowboy]

Just purchsed a ScanGaugeD but I am having trouble locating the J1708 or J1939 diagnostic port. (Guess I should have located the port BEFORE I bought..)

I have a 1998 Tradewinds coach with the 275 CAT. I believe it to be one of the first Tradewinds made since my Freightliner Chassis date is 12/96 and the National RV date is 3/97.

Can anyone help me locate this port?

Thanks!

[Theberrys]

My 1999 Tradewinds doesn't have a connector under the dash. I found it on the passengers side of the engine near the top about half way back. It's a J1708 and I had to run some 18 AWG wire to the front and add a new connector for the "D". I used this wire http://www.amazon.com/dp/B003KPYRJM/...0_M2C_ST1_dp_1 and and this connector OBD Diagnostics, Inc. - J1708 Deutsch Vehicle Connector, 6-position I spliced into the cable back on the engine and left the original connector in place. Solder and shrink tube is the best bet for the splices.

Dick

[MICowboy]

Thanks Dick,

After reading your post and looking at the chassis schematic from your shydrive, I was wondering if you looked beneath the dash for the data link twisted pair C792/793 (Page 2 of 4)? It is hard to tell from the schematic if this twisted pair is already located up there, but now i am wanting to tear my dash back open and have a look.

BTW, your schematics helped me fix my no dash light issue a few months ago. Thanks!

[Theberrys]

Mine was a rats nest of cables. The RS 485 wires could be there but I had to pull wires for the collison detector system and the toad break lndicator anyway so I just pulled three of the cables I linked too and was done with it. I spent a hour or so under the dash looking but started to cramp up and just solve it without finding existing wires.

I have about fifteen more manuals left to scan so I'll be adding some to the sky drive over the next week, so if you need more check back from time to time.

Here is a list of whats left to scan.

Freightliner Recreational Vehicle Chassis Owners Manual
Freightliner Recreational Vehicle Chassis Maintenance Manual
Replacement Backup Camera Spec sheet
RV EZLevel instructions
Attwood hudro flame Users Info Manual and installation manual
Owners Manual for Kwikee Electric Steps
A&E 8500,900 Universal HArdware Manual/Assy Diagram for A&E roller tube
Top view Electrical Systems layout for 1999 7371/7272 Model Tradewinds
Atwood LP Gas Range & Slidein Cooktops MPD 56280
Hydro Life Model HL-170 QC Kit filter install
Velvac Model 2005 Mirror Owners Manual
Freedom Seris Inverter/Charger Install Guide
Generac Generator install manual vintage 1999 gas/lp powered models
Dometic Ice Maker Operating instructions and parts list several models.

These will pretty much finish off the manuals I got with my coach.

Dick

[mrjimbo]

My 1998 I believe has the 300hp CAT. In fact I didn't know any of the trandwinds came with any less. Now you got me wondering, since I haven't seen anything that says 300hp on mine.

To answer your question, I found my port to the right of the steering column in a bundle of wires under the dash. It has a cap on it. I also have the same plug on the top of my engine, just laying next to the valve cover.

[Theberrys]

My 99 is a 3126 Cat 300 HP. It's on the placard on the engine toward the front of the coach. The numbers have a meaning the 312 is the HP and the 6 is the number of cylinders. I'm almost positive yours is the same. My chassis is a 1998 as is common so there really the same model for all practical purposes.
Dick

[mrjimbo]

I confirmed mine is indeed a 300hp 3126 Cat. It says so on the placard which on mine is on the valve cover near the front of the engine "rear of the rv".

I was working on running the wire to my scangauge. My diagnostic port is almost directly above the throttle pedal bundled with some other wires.

[Theberrys]

Originally Posted by mrjimbo

I confirmed mine is indeed a 300hp 3126 Cat. It says so on the placard which on mine is on the valve cover near the front of the engine "rear of the rv".

I was working on running the wire to my scangauge. My diagnostic port is almost directly above the throttle pedal bundled with some other wires.

I'm gonna look again for the connector up front although it really is moot at this point but others can really use the info in your post....... Thanks

The 300hp was really a non issue, I don't think they changed from 98 to 99. What really counts after you own the coach is does it perform up to your expectations on the road. There is a expensive device that can be added to bump the hp to 330 but I doubt we would even notice the change. Our coaches weigh around 26,350 and that won't change. With the Allison six speed we have an almost ideal drive train for the load. So all horse power numbers are good for is Macho chatting around the camp fire. If it drives fine I'll get buy with 9 to 10 mpg which the bigger engins don't get. In the new coaches there are three or four slides, pull out trays in the through storage bays and such which add weight and reduce performance and MPG. These features are nice but I haven't missed them, perhaps because I've never had them. I've owned my 99 since 2007 and really couldn't ask for more.

Dick

[MICowboy]

I looked all around the engine, and tore the dash apart looking for the port without any luck. So I called Freightliner and they said there was one port placed near the radiator surge tank. I will look again later... And hope I find it!

My Tradewinds is a little different than most... I do have a 275 hp Cat. It says so right on the CAT label, and I can also tell by the Freightliner VIN. The 6th & 7th VIN numbers are "JB" which indicate "Cat CFE/3126 (225-275hp) Diesel". I would bet yours are "JC" "Cat CFE/3126 (276-335hp) Diesel".

Also, my GVWR is smaller than yours. The 8th VIN number "C" indicates mine is a "19,501 to 26,000 GVWR". Again, I believe yours is a "A" "26,001 to 33,000".

My GVWR (per the Federal Certification Tag) is 24,850.

Other differnces I have noticed is that I don't have the typical Tradewinds line drawn sailboat on the mirror in the bedroom or on the two mirrors over the front seats. I have the "lovely" Tropi-Cal frosted mountain/moon/palm tree picture in the back and un-touched mirrors in the front. The light fixture over the dinette is the cheaper Dolphin version. And the storage space under the dinette have the hinges on the bottom of the cabinet. My old Dolphin had them on the side to swing open, and FIL's Tradewinds had the cabinet door built-in to the rolling shelf/basket. BUT HEY! I'm not complaining! I am a happy camper with my Tradewinds!

I'll post again if/when I find the data port, and Dick, I will take your advice to get my Scangauge D hooked up! Speaker wire!

[Theberrys]

I loooked over the accelerator pedal today in that large wire bundle and didn't find a Diag connector, so pulling the wire in mine wasn't a complete fubar. I guess I'm either blind or affected by the heat. It's logical that one would be there but I just can't find it. I have a new one now anyway. I'm just glad I live in a state that doesn't require smog checks or safety chacks on this unit.

BTW that 18 AWG stranded speaker wire worked fine, would be better if it was twisted pair but the length is well under the max for RS485 so it's not critical.

Dick

[Big Wheels]

I know this is a bit old but I have the same model and year as Dick and have located the J1708 plug in the dash area. In my case the plug was not visible from under the dash. There is a horizontal piece of plywood above the pedals and the plug was on top of that. The way I found it was to pull the gauge panel away from the dash far enough the get my hands in. I found it in the middle of a large bundle of wires and after clipping a few zip ties I was able to fish it past the plywood to hang just above the pedals.

I also had the second connector next to the engine but that one is useless when attempting to diagnose a cruise control problem at 40 miles and hour.