Brake Light Problem-- Freightliner Chassis

[richardawhite]

I have a 99 Newmar, Dutch Star, pusher. Went for a state inspection found I have two brake lights out. One in the center up high is working. I have checked everything at my level. I am hearing there are diodes in the brake light circuit. Found a Freightliner bulletin and sure enough there is a brake light harness kit. Part number 06-28598-00 cost $182.00 plus shipping.

Anyone had this problem?

I was wonder instead of spend that much money on a new and improved kit, could I find out the value and part number of the existing diodes that I expect are blown and replace for a lot less money. Freightliner dealer said no, need to buy the kit. Of course they would, lol. I believe the diodes are located at the base of the steering column?

Any help out there

Rich

[chucknewman]

I don't know why you would have diodes in the brake circuit, and if you did it is unlikely they all have opened circuited. Fuses are used to prevent those problems. Typically, diodes are used on the tow vehicle. I think you're headed in the wrong direction.

Is your Freightliner chassis red stop and turn signals (3 way circuit) or does it have separate amber turn signals (4 way circuit). If you have red turn and stop lights I would suspect either a fuse or the turn signal multi-switch assembly. But it is very difficult to troubleshoot without wiring diagrams. Does Freightliner have chassis wiring diagrams for sale?

Also, you didn't elaborate on what the Freightliner bulletin is for. Are you saying they have had issues with their harness and they recommend replacement? Or is the subject something else? I can't believe they want to replace the entire brake harness from the front to the rear of the chassis.

Chuck

[Charlieanddawn]

I have a 99 Dutchstar Freightliner Chassis. The grounds on the brake lights and other lights in back corrode and loose connection. Check the connections by removing the light assembly. The grounds just fall off. 13 yrs. of hwy. not the harness but a simple loss of ground.

[dickandlois]

You can check out the Roadmaster web page. They have diodes that go in the brake and turn signal lines, They a commonly used to protect the coach circuits from shorts when pulling a toad. That helps keep from blowing fuses and trying to find them. At time it keeps the coach lights working even if there is a problem with the Toad or interconnect harness.

Ti's that stitch in time save 9 issue.

R.M.

[whiteeagle]

You could also post this question on and/or join the iRV2 forum... they have a couple Freightliner specialists and a online chat session on Wed at 7PM for all things about Freightliner Chassis ....

[hermanmullins]

Rich,

Welcome to the Forum.

I made some inquiries and I believe you need a third number on the end of your part number (06-28598-00?) if it is a '0' then it is a good part number but is hard to find. Such a wiring harness will have both tail, turn and stop lights in the same harness.

Do you have Emergency flashers?

If you have a connection on the rear of your coach to connect you toad, connect your toad and see if you have brake light on the toad. I don't believe you have a ground problem because if you did, none of your tail lights would work. I am basing this on the fact that most Tail and Stop lights are in the same bulb.To check for a ground remove the bulb and check the rim of the connection to known ground on your coach. If you have continuity then you do not have a ground problem.

I know this is a dumb question but are your sure your bulbs are OK?

R.M. I have never heard of diodes in a vehicle wiring harness (of course I learn something new every day). I do know and have diodes on my toad (I wired them in myself) to keep the reverse current from flowing back into the toads computer (big problems if that happens), but not in my coach.

[dickandlois]

Rich,

Did you find the problem?

There are 2 diodes in parallel,located in the turn signal power feed line. 6 amp rating, a voltage rating of 50 volts should work fine.

Look at my photos in photo section under Alternator Problems to get testing info. for the diodes.

Remember to get the polarity correct if they test bad !!! and need to be replaced.

Then if you have a trailer towing module in your unit its a totally different setup !!!

With the Vin Number and a call to Freightliner you should be able to get the proper drawings for your chassis.

R.M.

[dickandlois]

Hi Rich,

I just found you note in the comment section.

Glad you found the bad diodes. They do hide them in the darnedest places,almost impossible to find them.

The fact that they where burned open had to make for a good day when you located them.

All is well that ends well and now you know right where they are located. Having working brake lights is good.

Hope that you will share you knowledge with others.

R.M.s