Re-Imagining the "Brown Wire Mod"

Dan Sarandrea (Phila)

Waitin' On Parts...
I had intentions of implementing Bob Brown's patented and improved Brown Wire Mod, but when I got into it, the hard part was getting the addditional wire to seat nicely in the four-prong junction fitted to the front edge of the later cars ('84 and up) ATC fuse box. Not to mention that these are push on spade connectors which aren't the greatest for connectivity in the first place.

And I wanted to implement the Bob Brown no-cut headlight relay mod as well as the Leiszig wiper relay mod, too. But no matter what I did, I ended up with unsightly wires coming off the battery postive post and a mishmash of inline fuses.

So I decided to over-engineer and over-build a replacement power distribution system.:)

First, fit a thru-the-bulkhead insulated power post thu the existing cable hole. The good news is that this fits nicely under the stock battery cover.
IMG_1933-1.jpg


Then fab up a replacement starter/main power cable, adding two wire sizes for good measure (from #4 to #0). Fit said starter cable to the inside of the insulated power post. Since the FI power wire runs along with the main cable, make up a #10 replacement. Careful routing around the heater pipes.

IMG_1937-1.jpg


Now that I have an interior power post, I was able to use this as the jumping off point to feed the wiper relays and the headlight relays.

IMG_1935-1.jpg


I executed my interpretation of the brown wire mod by running a branch from the main power post to a surface mounted power post located just behind the ATC fuse box. I used #6 wire with copper lugs.
IMG_1930-1.jpg


The two smaller wires called out in the pic above are the two original wires that occupy two of the four male spades that live in the original power junction receptacle originally located at the front of the ATC fusebox. Replaced their female spade connectors with copper rings. The third wire, the original brown wire that comes from the battery, is replaced by the #6 branch.

I will be posting three more threads in the near future with pix of how I did the wiper relays, the headlight relays, the hard start relay and an upsize of the main alternator/charging wire.
 
Last edited:
Nice work!

Very clean setup! :thumbsup: Way better than having all those wires going to the battery terminal. Nice job.
 
Dan, now you tell us

after I did the brown wire and headlight relay mod several months ago. I'm no card carrying electrician and my work is definitely not a clean job like yours, but it does somehow work. Brightened up the headlights, dash lights better, and the voltage meter sits at a significantly higher position.

Can't wait to see your post about the wiper relay.
Mike
 
after I did the brown wire and headlight relay mod several months ago. I'm no card carrying electrician and my work is definitely not a clean job like yours, but it does somehow work. Brightened up the headlights, dash lights better, and the voltage meter sits at a significantly higher position.

Can't wait to see your post about the wiper relay.
Mike

If you haven't done the wiper relay mod, I would 1000% recommend it!
 
Good work Dan,

You're addressing the inadequate wire gauge issues head-on.
I can't do on mine in the same way like what you're doing, (the stud attachment, etc) but increasing the gauge of the wire to the fuse block is a big help to the rest of the car.
You're making neat work of it and I notice all the attention to detail, heat shrink and all.

I had cut a groove in my + battery post and added (soldered) another 10Ga brown wire in parallel to the brown wire gong to the fuse box, essentially doubling the current feed, but that's the extent of what I've done to increase the current. (along with a 4Ga ground wire)
The feed to the insertable headlight mod was taken from the point of that connection inside the fuse box, so no one would see extra wires from the battery. -Just my way, but yours looks great. :thumbsup:

Keep us posted with your progress and thanks for posting!
 
Nice work!

I wonder why there is not a mod for the headlight motor relay - that seems to be the largest current draw I have now - hooked up a SUN VAT40 yesterday, and when the parking lights are turned on, the motors operating draw anywhere from 5-10amps . I've been looking through the wiring diagrams, but I find the Fiat schematics hard to read compared to Volvo - the need for reading glasses & the lack of indicated potential during operation in the schematics don't help a visual learner :huh2:
 
They are powered at the same place...

...as the junction for the brown wire mod. So, doing the Brown Wire Mod should be all that's needed. Maybe upping the wire sized from the junction to the fuse panel connection. Adding more relays to the headlight cover motor circuits might just add unneeded complexity.

The real problem for the motors is all the connections, the grounds, and most of all a need for lubrication inside the motors themselves and on the bronze cover pivot bushings.
 
Back
Top