Famous Brown Wire

[74SpyderGates]

Hi there,

Can somebody please tell me where this famous brown wire is located. I have problems with my lights. very dim. Does anyone have pictures. And also what the correct procedure is to fix this brown wire problem.

Tks in advance,
Gates...

[rlux4]

Here's a tutorial on the fix:
http://www.mirafiori.com/faq/content/bwfix/bwfix.htm
Ron

[fillupd]

I just completed mine. I can't believe how easy it was. Every thing works better. Wipers picked up speed, dash light bright, radio worked better. If I knew how easy this was I would have done this a long time ago. Best 8 bucks I ever spent.

Go to the trunk and unhook the battery. Remove back seat, and run a wire through the grommet into the car. I loosed up both grommet housings to put the wire through. Pull enough to go a few feet past the front seat so you can weave it up to the switch. Pull up the side of the carpet a little and stick the wire right along side the big green wire all the way to the firewall and then make the turn up to the switch.
Put a # 10 spade connector on the end when you get it closer to the switch. Crimp it on good. I put a small dab of elec grease on it before plugging it in.
There is the empty spade sticking out the back of the switch so thread your new wire up there and plug it in. I put a # 10 closed loop connector to bolt on to my battery post bolt. I drilled it out to a 5/16" hole and it is a perfect snug fit.

I actually took the 5 minutes to unplug the switch and pull it almost all the way out to make sure I was in # 30 spade. Its hard to be positive which one it is. It felt like there was only that one but I got nervous and had to look. It can be done without removal now that I have seen what was going on.

Cleaning the plug is a plus so unhook it anyway and put a tiny bit of elec grease on it too. It was all really easy and gave me a chance to clean up the battery posts and check the switch plug in.

I also hooked up my elec fan to the alt. power instead of the original fan power wire. ( the original fan wire worked well though but I wanted to change it) I got a control and aluminum radiator from Mark. My fan now turns on at 195 and off at 184. It can idle for as long as I please. The radiator was a little trickier than the wire. I had to take off the pollution pump (which I didn't need) and a very small amount of manipulating the mounts and hoses to get them to fit good. Cutting the saddle off the bottom took about 1 minute with a hack saw. I got the sway bar as low as possible to get a spacer in there and get the nuts back on. I did not get the install kit from Mark so my install may have been a little more foot work on my part but I'm happy I did both upgrades. With the prestone fill tee at the heater hose and the radiator a little higher, no burping necessary.
(I have a 1978 Spider.)

[pooldoctorstl]

You should also install relays on the light circuit. Do a search here on how to do it. Our cars have the full power for the lights running through the light switch which creates a voltage drop and reduced voltage to the lights, and it is a fire hazard if the switch gets bad and overheats (not good). I was amazed at how much brighter my lights were when I did it. You can buy the relays at any auto parts store for less than $10 each or IAP has a kit with instructions that will make it easier.

http://www.international-auto.com/iap-h ... de-kit.cfm

Jeff

[aj81spider]

I second the comment about the headlight relays. I just put in the IAP wiring kit this weekend and drove at night for the first time tonight. It's like having a new car. The headlights went from being dim and perhaps a safety hazard to the intensity of any other car on the road.

I highly recommend the kit. You might save a few bucks by buying relays and wire yourself, but the kit comes nicely jacketed, color coded, and has connectors and terminals already attached. Two things I experienced installing it:

> The routing of the wires in my 1981 was nowhere near as simple as described in the instructions. The "hole" they tell you to run the wires through doesn't go through to the open area of the fender behind the lights. I eventually routed the wire through a hole behind my windshield washer tank (which I had to remove to get to). It took 10 minutes to pull the wires, but an hour to figure out where.

> The hole they have you drill and grommet in the headlight bucket isn't big enough to get their connectors through. Either buy some bigger grommets and drill a bigger hole or do what I did - cut the connectors off and solder and heat shrink the wire.

Otherwise the kit was easy to install and the results were fantastic.

[azygoustoyou]

I have to do this to my car too. Since all the wiring is out. I guess this might be a good time to try to figure this out.

[DocGraphics]

These are both upgrades I plan to do to my 78 as I start cleaning it up & fixing it's gremlins.

I'm getting a nice list going of fixes/upgrades to do, some right now, some as I go & some later.
This site definatelly helps in Identifying the issue to be addressed first as well as great ideas for the future.

Now if I can just find a cure for the blindness caused by having to read ALL the post here.
Always something more to read, who needs sleep?

[tartan18]

I also got the IAP headlight kit for my 1975 Spider and installed it today. The challenge for tomorrow is to find out why neither the driver's side headlight or marker (side light) are working. Everything was working fine before I started the install. Any ideas on what to check would be appreciated and unless I hear differently I will begin tracing the wiring in the morning.

[tartan18]

The IAP relay kit is installed and everything is working correctly.

Last item on my list is to do the "brown wire fix."

I have run a second 10 gauge wire from the starter but I don't know which spade to connect it to on the ignition switch. Here is a picture of my switch.



According to to the Mirafioria site http://www.mirafiori.com/faq/content/bwfix/bwfix.htm I am suppose to connect the new brown wire to an extra 30 terminal. I don't appear to have an extra because the exiting wires take up everything except the two spades marked "Int".

My exiting Black wire goes to terminal 30/1, the existing Pink and Blue/Black wires go to terminal 15, the original Brown wire goes to terminal 30 and the existing Red wire goes to terminal 50. I don't have anything presently connected to the two terminals marked "Int."

Any ideas to help me figure out where to connect the NEW brown wire? Thanks a bunch folks for this forum.

[BenjamminsFiat]

Only some of the ignition switches had extra "30" terminals on the back. Mine did when I did my "Brown Wire Fix" so I was able to just put a connector on the stripped end of the new wire I ran and plug it into the switch on this extra terminal.

However, since your switch doesn't have an extra, you'll have to splice both the new wire you ran AND the older brown wire to the single "30" terminal on your switch. Remember, the whole purpose of the modification is just to run a new "cleaner" source of electricity to the switch itself (effectively rejuvenating the existing "Brown Wire").

Please someone else correct me if I'm wrong.

[FortFiat79]

I am extremely new to the fiat family. When I turn on my head lights the electrical system drops to 4 V (scary I know). Do the veteran owners out there think that the above fixes will help this issue or should I look elsewhere?

[divace73]

I am extremely new to the fiat family. When I turn on my head lights the electrical system drops to 4 V (scary I know). Do the veteran owners out there think that the above fixes will help this issue or should I look elsewhere?

Yes and more than likely your ignition switch may have built up resistance, I actually pulled mine apart like the mirafiori site recommended but used screws from a hobby shop which had a smaller in diameter to suit the hole size.
Depending on the year or your ignition switch and (if I had known previously) you can buy just the electrical contact that is housed in the barrel (an genuine too).
Clean up all you ground points and check with a multimeter up the line where power is getting lost. You'll find you'll get voltage drops at point where there is a connector, fuse etc (anything other than the wire itself)
And it is a must to relay your head lights.
Hope this helps

[donerehart]

I also am planning on doing this... Sounds like we need to keep this post alive until we get it done...

[westy64]

I am confused about one detail regarding the brown wire fix.
Maybe I am confused about 2 different goals,

increase the efficiency of the circuits (dash board, wipers, head lights)
and
try to prevent my ignition switch from damages caused by all power passing through

Are these two targets compatible ?