raise your hand if you like dodge wiring
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Forum Name: General Discussion
Forum Discription: General Mobile Electronics Questions and Answers
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=116045
Printed Date: May 18, 2024 at 12:19 AM
Topic: raise your hand if you like dodge wiring
Posted By: nfrank89
Subject: raise your hand if you like dodge wiring
Date Posted: September 02, 2009 at 2:01 AM
hahaha im kidding of course...
can someone please explain to me why chrystler chose to wire vehicles using resistance? it makes it almost impossible to diagnose some problems. disconnect this wire.. the headlights turn on... wth? plug this one in... the power locks stop working and the domelight goes off... WHY WOULD THEY DO THIS?!
Replies:
Posted By: tommy...
Date Posted: September 02, 2009 at 9:23 AM
Excellence in engineering...And w/ multiplexing...It saved them 300 lbs of wiring harness's...!
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M.E.C.P & First-Class
Go slow and drink lots of water...Procrastinators' Unite...Tomorrow!
Posted By: KPierson
Date Posted: September 02, 2009 at 10:32 AM
Resistance (when used correctly) can change voltage. Voltage can be precisely monitored to allow more then one function to be transmitted on a line. I believe it was BMW that first started using multiplexing in vehicles, but in the end it saves a lot of weight and cost. If you are having issues with simple multiplex systems stay away from CAN and LIN busses! ------------- Kevin Pierson
Posted By: nfrank89
Date Posted: September 03, 2009 at 5:08 AM
okay, that makes sense. yeah i realised they saved a lot of wire this way. it's smart and interesting but it's also very hard to diagnose problems. i was working on a 2002 ram and the problem was the lights for the gear position and the odometer stayed on at all times. how would one go about diagnosing this problem? also, at what point did they start using this system? is it used on all vehicles after a perticular year?
Posted By: Velocity Motors
Date Posted: September 03, 2009 at 12:23 PM
Every model starting at different yers with the multiplex. It started in the mid 90's with the higher end vehicles having the resistance based wires. I love working with the Dodge vehicles with the CANBUS stuff.
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Jeff
Velocity Custom Home Theater
Mobile Audio/Video Specialist
Morden, Manitoba CANADA
Posted By: KPierson
Date Posted: September 03, 2009 at 12:48 PM
The best way to troubleshoot a problem like that is to first determine what controls those lights. Next, you have to figure out what, under normal circumstances, would turn those lights on. Lastly, you figure out what has changed. I realize that this is a very simplistic approach, but if you can figure out each of these things you'll at least know where to start looking. ------------- Kevin Pierson
Posted By: howie ll
Date Posted: September 05, 2009 at 3:47 PM
The other CAN /LIN system advantage is that it offers built in diagnostic ability, apart from the weight and cost saving, chips are cheaper than copper wire. Come to think of it, KP was almost right , BMW used it on the secondary lock control from 98, Mercedes from about 95 on the locks and the good old Ford Probe from who knows when. Did I call a Probe good? What a nasty car.
Posted By: nfrank89
Date Posted: September 07, 2009 at 4:23 AM
can you explain can and lin busses to me? and yeah i was thinking they must have some kind of built in diagnostic computer...
and kpierson... isnt this the troubleshooting process for any system? lol
Posted By: KPierson
Date Posted: September 07, 2009 at 7:22 AM
Yes, basic troubleshooting rules. You would be better off to do a google search for the busses, but from memory the basics are: CAN bus - two wire high speed system where there is no master controlling communication. Any module on the bus can send a message to any (or all) module at any given time, assuming the bus is clear. There is a system in place to request and arbitrate which module has control of the bus. LIN bus - one wire low speed system where the master must start all communications. This was designed to be a "low cost" bus and typically is used on non critical tasks, like body control stuff . Both systems transmit serial data on the bus. CAN busses are cool because they can detect wiring faults and if a wire is damaged the bus will automatically switch to a reduced speed one wire bus to keep things running. There is obviously, much, much more to them then this, this is just a basic outline. ------------- Kevin Pierson
Posted By: nfrank89
Date Posted: September 07, 2009 at 4:05 PM
so basically they turn the whole vehicle into a circuit board
Posted By: robertsc
Date Posted: September 13, 2009 at 9:02 PM
I can tell you that from working on several dodge trucks with light shutoff problems. Every time it was the underhood fusebox/relaybox/bodycontrolmodule. If you dissasemble the fuse box you will find all the relays and fuses and computer are connected to a pc board that lays on the bottom. Once the protective coating dissappears the water attacks the pc board causing wacky results. I wouldn't reccomend dissassebling this unless you determine that this is what it is and that its hot for the faint of heart.
Posted By: howie ll
Date Posted: September 14, 2009 at 2:46 AM
robertsc, you should have worked on Lancias about 15-20 years ago, apart from when installing a head unit and having to remove the heater rods, a joy to reinstall, all the electrical components, fuseboxes, relays were EXPOSED under the hood. Apart from the ongoing rust and build quality factors EVERY electrical problem was down to that, also early minis with the engine bay fusebox (all 4fuses) first thing you did was to move it inside.
Posted By: robertsc
Date Posted: September 14, 2009 at 7:11 PM
Sound like a fine engineer going bangup work did anybody give him a raise?
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