light issue in 2005 Neon

[Tommy2348]

It started with the running lights, my girlfriend was driving and realized the dash lights and tail lights were not working. later on I bypassed the MFS (multi function switch) and wired in a new fused switch, so I have running lights and dash lights. about a month later I am driving and hit the turn signal, nothing happens. so I go digging, the hazard fuse was blown, as soon as i put in a new one, it pops the fuse, GREAT. I didn't have time to go looking for a short so I started double checking everything else to make sure I didn't have another problem. Well in the process I found that I have no brake lights. so I checked and the fuse for that was blown as well, now its getting annoying, I get in the car and hit the brake and hear a pop, fuses blows again. I know this is a common problem, I just don't know where to begin, I want to bypass the MFS to see if the brake lights will work without blowing the fuse to see if it is causing the problem but I do not know the pin out for the 20 prong connector. so I need help Identifying which prong goes to what.

[A@ron]

I bet your MFS is on its way out or the 24 pin connector has melted a bit.

Here's a pin out I've got saved.

1--White/Tan--Center brake power
2--Green--Left turn arrow on cluster
3--Red/White--Run/Acc hot power to flasher from fuse 1 (turn signals?)
4--Green/Red--Right turn signal output
5--Brown/Red--Left turn signal output
6--Tan--Right turn arrow on cluster
7--Black/Orange--Ground
8--Red--Panel lights from dimmer
9--Black/Yellow--Tail lights, front side markers, license plate lamp power out
10-No Connection
11-White--Always hot power to flasher from fuse 15 (emergency flashers?)
12-No Connection
13-No Connection
14-No Connection
15-No Connection
16-Violet/White--Low beam power out (the pin that always melts)
17-Green/Brown--High beam power out
18-Blue/Orange--Low and high beam power in from fuse 16
19-Blue/Orange--Low and high beam power in from fuse 16
20-Pink/Red--Tail lights, front side markers, license plate lamp power in from fuse 15

[Tommy2348]

Thanks A@ron, this should halp me narrow down the cause of the problem

[Tommy2348]

I have been looking for a place to get the dimmer switch connector as cheap as possible and I am having trouble because everyone seems to use different part numbers. The cheapest I have been able to find is $55.76 at stockwise auto. I have tried ebay, craigslist, autozone, amazon, with no luck on finding it cheaper. but for anyone else that may be looking for this part, the part numbers I have been able to find so far are as follows:
DODGE: #5183442AA
AIRTEX: #1P1610
Carquest: #57-5391
Autozone: #978
UPC: #080044933830
???? #C205

[A@ron]

Dimmer switch connector? Do you mean the 20 Pin multifunction switch connector?

That connector is the same as the ones that go to the doors so you can go to a junk yard with a pocket screw driver and pull one of the plugs to the doors apart or just cut it off and disassembly it at home and use the non-melted plastic bits with your old wire/pins.

The reason why you use one of the ones going to the doors is because those won't be melted and a junk yard will be cheaper than $55 I bet.

[Tommy2348]

yeah, usually when I search online it comes up as dimmer but it is the 20 pin for the MFS. they use them in the doors? would I be able to cut the old one out and splice in the one from the door? or will I need to do some modifications? also, what all does the plug in the door control? reason I am asking is because if possible I might just snag the one out of my door for for now until I get another one, I am going to need the car Thursday and won't be able to go to the junkyard by then, do you think I can get by with taking the one out of my car door for now?

[A@ron]

eh I wouldn't go pulling one from my daily drivers door to use it in the MFS personally.

You basically are just going to take a donor vehicle disassemble the wiring harness plastics using something like a mini screw driver and then use the new plastic parts in place of your old melted plastic part at the MFS. Moving the old wires and pins to the new plastic part and then snapping it together.

[Tommy2348]

I know it would not be advisable, but for a quick fix just for a day? I have to drive 40 miles down a main highway in Florida Friday, I don't want to do it with no brake lights no flashers, or hazards, I'ss stick out like a sore thumb, not to mention the possibilty of getting rear ended or worse, after the appointment I can swing by a junkyard and gut a Neon there to get another one, I just can't get to a junkyard before then is my problem, this is pretty much my only option

[A@ron]

in theory you could undo the plastic plug from one of the doors just make sure you isolate the wires from each other so they don't make inadvertent contact and do things like ground the power lock/power mirror wires and blow fuses.

[Coilwire]

Kind of old post but found out MFS aka multifunction switch can be taken apart. Rewired headlights and fog lights to relays running off feeds from MFS aka cutting wires that ran to lights and attaching them to a relay rather than running full power through MFS. Opening up MFS the grease gets old and baked on contacts in it from it having full power going through it to run lights. Took a scotchbrite pad very lightly went around on contacts to remove baked on grease to shine up contacts while in there the part that works fog lamps had worn a grove making fog lamp circuit jumpy wouldnt stay on with a piece of plastic from store packaging container and superglue made up a pad to fix fog light issue. Also took apart wiper switch cleaned that up to with SuperLube dielectric grease applied a new not so much grease coating the MFS switch works like new again. PIN connection on back not to bad or melted on back open it up being careful and take pics disassembling it so get it back together right but not too complicated. Been several months using it still working fine here.

[occasional demons]

Yeah, I suggested using the MFS to switch relays a few years back. I even posted a modified FSM wiring diagram on how to do it. That was lost due to PhotoBucket getting greedy a few years ago.

I don't know if anyone ever followed through. I never did, because I didn't have any issues. I will probably do it on my 2000 when I get to that point in getting the car closer to a running vehicle.

210,000 miles, and the connector is only a little discolored.

I know it would not be advisable, but for a quick fix just for a day?

LOL, I hope they didn't attempt it. The door connector isn't exactly a simple thing to access, let alone take the wires out, record where they came from, and go to the trouble of swapping the MFS wires in. It would need at least a few hours as to not rush, and make mistakes.

Edit: Apparently it still exists....

From 2013.



https://www.forum.2gn.org/viewtopic.php ... ys#p993906