[B]Zonker's Brown Wire mod, with pics:[/B]

zonker

zonker

Just Another FIAT Freak
Although I called this "zonkers brown wire mod", I only lay claim to this design of this brown wire mod. Others have been doing this mod for years, and have Bob Brown to thank for his innovation in discovering a fix for many of the X's electrical woes.

Illustrations and directions apply to 1974-1978 Models - but 1979 and later can make thsese same changes but with possibly a different more access friendly mounting point for the distribution post, but I've heard from a late model owner that mounting the post as shown behind the glove box still works well.

This style of BWM advantages are there's no factory wires to cut/splice/solder/or remove to make this work, making this mod 100% reversable, and once done is completely hidden from view. In addition, this design unloads the ignition switch, which sees way too much current for it's own good. I'll bet when you disconnect C19 connector you will see heat discoloration at the terminal to confirm this occurance.

Parts needed (and ebay links):
1. 30 amp bosch relay or equilvalent with harness http://www.ebay.com/itm/30-40-AMP-RELAY-HEAVY-DUTY-WITH-WIRE-HARNESS-12-VOLT-5-PRONG-SPDT-BOSCH-/171076844210?pt=LH_DefaultDomain_0&hash=item27d4f97ab2
2. 6 ft of 8 gauge wire
3. 10 ft of 10 gauge wire
4. a couple feet of 14 gauge wire
5. butt connectors http://www.ebay.com/itm/15-Crimpable-Vinyl-Car-Radio-Audio-Alarm-Wire-Butt-Connectors-Terminals-Combo-/200937460073?pt=LH_DefaultDomain_0&hash=item2ec8ce5169
4. Insulated power distribution post http://www.ebay.com/itm/77025-BATTERY-POWER-JUNCTION-DISTRIBUTION-POST-1-4-X-20-WITH-RED-BASE-/321398920241?hash=item4ad4de5431&vxp=mtr
5. One or two 8 gauge 1/4" eyelets http://www.ebay.com/itm/8-GAUGE-VINYL-1-4-RING-10-PK-CRIMP-TERMINAL-CONNECTOR-AWG-GA-CAR-EYE-RVRT814-/271634867688?pt=LH_DefaultDomain_0&hash=item3f3eb325e8
6. four 10 gauge 1/4" eyelet solderless ring terminalshttp://www.ebay.com/itm/20-Pcs-Wire-Ring-Terminals-Vinyl-Yel-12-10-Gauge-1-4-Car-Audio-CRIMP-Connectors-/191422585580?pt=LH_DefaultDomain_0&hash=item2c91acdaec
7. one 10 gauge piggyback female spade terminal http://www.ebay.com/itm/SPADE-TERMINAL-PIGGY-BACK-CIRCUIT-TAP-CONNECTOR-250-12-10-GAUGE-YELLOW-X10-/291475343753?pt=LH_DefaultDomain_2&hash=item43dd48c989
8. four 14 gauge male spade terminals http://www.ebay.com/itm/100-16-14-Gauge-Insulated-25-Male-Spade-Wire-Connector-Electrical-Terminal-/231278960056?pt=LH_DefaultDomain_0&hash=item35d94cddb8
9. four 14 gauge female spade terminals http://www.ebay.com/itm/SPADE-TERMINAL-FEMALE-4-8-mm-16-14-GAUGE-BLUE-ELECTRONICS-AUTO-ETC-X25-/291464239313?pt=LH_DefaultDomain_2&hash=item43dc9f58d1
10. 1/4" Heat shrink tubing for covering the female spade amd sealing the solderless connections (not pictured here but I did do it afterwards) http://www.ebay.com/itm/6mm-1-4-Heat-Shrink-Tubing-Shrinkable-Tube-3-Meters-One-Price-Free-Shipping-/391164107636?pt=LH_DefaultDomain_0&hash=item5b13329b74
11. A few zip ties to safely route the wires under the dash. I zip-tied the relay to the hydraulic hard line under the dash.

1. Start with a new 8 gauge wire at the battery +, and feed it thru the firewall at the rubber grommet where the batt cable and brown wire enter the cabin.


2. Inside on the dash, remove the passenger side "bertone" grille. Mount up a 1/4" insulated post. This will be your new wire distribution point.

I got mine here: http://www.ebay.com/itm/77025-BATTERY-POWER-JUNCTION-DISTRIBUTION-POST-1-4-X-20-WITH-RED-BASE-/321398920241?hash=item4ad4de5431&vxp=mtr


3. From your distribution post, make two 10 gauge wires and run them it to the fusebox and the steering column area.



4. At the fuse panel, add a piggyback terminal and connect the new wire to either fuse B(2), I(9), or L(10). All three of these fuses are connected to the 12V unswitched circuits in the fuse box being fed current by the pink wire from the C9 brown wire junction (terminals 9 and 10 have a metal link connecting them and terminal 2 runs a white wire from terminal 9). On my '74 I piggybacked #2, but on my '78 I piggybacked #10 (2 works well but 9 or 10 is recommended for '75 up).


5. At the steering column, remove the cover and find the ignition switch connector C19 (4 wires). This will be your relay point for feeding voltage to the 12V " ignition on" switched circuits.
On the switch side (male terminals on connector) you should have brown, red, black, and blue with stripe wires. On the harness side ( female terminals on connector) you should have brown, red, black and a combo pink & blue with stripe wires. Make 3 short "jumper wires with male and female spade terminals at each end and connect them to the red, black, and brown wires. Then, the blue stripe wire (male terminal side) will need be connected to #86 on the new relay. The pink and blue with stripe wires (female terminal side) will be connected to terminal 87 on the relay. The #30 terminal on the relay gets the new 10 gauge wire from your distribution post, and finally a ground wire needs to be made from the body to terminal #85.
ltcCSjI.jpg
 
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outstanding!!

once I get the harness in black beauty, and change the fuse box over to a spade type fuse, I will take all that you have done and implement on her.
good job...................it does work?:laugh:
mikemo
 
Yep - works great. Volt needle barely moves, turn signals are more constant, and wipers move faster. The ignition switch relay takes care of all current originally provided by the brown wire, and the fuse box jumper takes care of all items supplied by the pink wire, and that is the only two 12V current sources from the battery to inside the car.

In addition to this, I've done 2 other mods -

1. I added HID bulbs to H4 housings and power them with a relay connected to #8 on the fuse box. For those of you running standard or halogen bulbs, you can add a relay kit like Bob Browns or something like http://www.ebay.com/itm/H4-H4-Headlight-Halogen-Booster-Wire-Harness-Connector-Relay-Fuse-Socket-HLRG-/111385189028?hash=item19ef131aa4&vxp=mtr. This relieves the largest load on the black wire coming from the ignition switch, as well as the headlight switch.

2. I added a starter relay to increase current to the solenoid. This made for a RIGHT NOW engagement of the starter when you turn the key :) Real easy to do - this mod unloads the red wire coming from the ignition switch.
 
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Thanks. Just What I Needed to Know

Couple of Quick Questions.
#1 Is that your 78's Fuse Box
#2 If YES, why doesn't it look like Mine?


Disregard the Big Red wire on #12. First BWM attempt. Soon as I hooked up the Battery, I realized that is the Headlight motor circuit, then figured out the PO had the Fuse Box mounted Upside Down. I've since moved it to #2, per instructions I found here. After reading this I'll move it to #9 or #10.

Perfect timing. Next week, I get to go back in to replace some leaky Brake hoses to the Master and a Speedo Cable, so perfect time to do this mod.

Figured it out. Looking at the top instead of the Bottom side. This makes more sense.
 
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Red Bull 78 said:
Couple of Quick Questions.
#1 Is that your 78's Fuse Box
Click to expand...

The fuse box pic was the '74, but the '78 looks similar like your pics - In the pic above, the new 10 gauge wire should go to the fourth terminal from the left (fuse 9). That will link your new wire to 2, 9, and 10 of the unswitched current. Make sure you don't hook up the wire on the other side, that is the side of the fusebox that gets current after the fuse, and you want this to be before the fuses do their thing.
 
Hey! Zonker. Or Anyone Else

Early on I was looking for way to simplify the BWM and KISS it. (Keep It Simple, Stupid).

I grabbed this on a trip to "The Bone Yard". It's a Relay Mounting Bracket, similar to the one on my 78 "X", but for my 90 Geo, so I have the Wiring Diagram.



I ordered THREE of the Relays you suggested and I'm thinking of mounting them in this rig and locating it somewhere neat & clean . Those BIG Amp Fuses are just a Plus.
 
I like the idea - for me if i was to fuse anything more, I'd add fuses to the brown and BWM wires, either in the form of fusible link wire inline, or a fuse holder off the battery in the frunk. Since i removed the AC on the '78, there is an inline holder w/ a GBC25 fuse under the dash that used to be for the A/C control circuit. I unplugged the unused red wire and put my headlight relay main wire to it.
 
1979 Mod

Thank you for the info, I will be doing this mod to my 1979 X soon. Any significant differences for a 1979? I assume I can do the post easily behind the glove box, I have had that out and it looks like plenty of room back there.

Can you detail the headlight relay and starter relay, I am thinking of going to HID lights as well and the starter relay would take care of all issues.

Thanks,

Paul Willging
 
If you can reach the panel thru the glovebox then it does make sense to put it there :thumbsup:

As for the headlight and starter relay - I'll start new threads for them.

One more pic - this one is the Positive post mount on my '78 (with dash in place). For clarification's sake - the three wires are:
Brown wire: lead running to terminal 30 on new ignition relay
Red wire in middle: runs from positive battery post (power source)
Red wire on bottom: runs to fusebox and hooks to power side of fuse #9

5KlIt0l.jpg
 
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One More Question

In this pic, the BROWN wire to the Relay is Your BWM power supply? Right?

http://i.imgur.com/ltcCSjI.jpg

For clarity sake, I'm using a 10 G Clear Red wire for all my BMW Power Supply lines, so as not to be confused with any OEM wiring, in the future.

Old Thomas is going to be a Busy Beaver for awhile. My DO LIST Has 13 Items, with 6 Sub categories. Including.
!. R&R Brakes Hoses & Speedo Cable w/New Sheath.
While The column is Out of the way.
2. Doing Your BWM
3. Headlight Relay Kit
4. New Fuel Sender unit

Then I can get back to the Drivability & Reliability Issues.

Thank heaven my Buddy's Grandkids speak Spanish instead of Italian. At least they won't understand what they're hearing coming from the Gringo in the garage. :laugh:
 
Red Bull 78 said:
In this pic, the BROWN wire to the Relay is Your BWM power supply? Right?

http://i.imgur.com/ltcCSjI.jpg
Thank heaven my Buddy's Grandkids speak Spanish instead of Italian. At least they won't understand what they're hearing coming from the Gringo in the garage. :laugh:
Click to expand...

Yep, the wire to the right in the pic is a new brown wire coming from the distribution post to relay terminal #30.

And Italian and Spanish cuss words aren't that far apart so be careful ;)
 
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Based on that Info

zonker said:
... That will link your new wire to 2, 9, and 10 of the unswitched current. Make sure you don't hook up the wire on the other side, that is the side of the fusebox that gets current after the fuse, and you want this to be before the fuses do their thing.
Click to expand...

I should Piggy-back my BWM to #1 on the two Lt Blue/ Lt Blue w/Black dots?
 
The blue with black wire on fuse A power side is a 12v switched lead that gets its current from the ignition switch. The switch relay number 87 at the column takes care of that. For the BWM wire, stick to hooking it up at fuse number 9, which is blank with no wires in your fuse box pic.
 
Great Job

Looks like you covered all the bases while keeping your car's electrical harness in-tact and original.
Nice work!

The $8 headlight harness looks a little scary to me. I'd be interested in knowing how folks make (made)
out with one of these, particularly with the installation process and the wire gauge used in the assembly.
 
bbrown said:
Looks like you covered all the bases while keeping your car's electrical harness in-tact and original.
Nice work!

The $8 headlight harness looks a little scary to me. I'd be interested in knowing how folks make (made)
out with one of these, particularly with the installation process and the wire gauge used in the assembly.
Click to expand...

Thank you for the kind words, Bob. As for the headlight relay, without a doubt for $8 one is not getting the same caliber of quality and work that your kits are.

I installed one of these HID relay kits in my '78 when I installed single beam HID ballasts/bulbs, and they are working ok but in order to install the kit as is, without modifying the wires between headlamps, I had to drill pass thru holes to get the harness from the drivers relay side to the passenger side. Judging by the pics of the $8 relay, a similar set of holes would need to be drilled in order to make the kit reach.

 
OK, Dummy Me Needs Help

I'm sitting here looking at this relay and looking at your pic, trying to figure out which color wire goes to which Terminal on the Relay and which one goes where on the BWM. The flash in your pic washed out the color so the Yellow & White are confusing and I don't see the Red anywhere.
Sorry! My resident Electrician Buddy I'd usually ask dumb questions like this, has been working in Afghanistan for the last year.

http://i.imgur.com/ltcCSjI.jpg
 
Red Bull 78 said:
I'm sitting here looking at this relay and looking at your pic, trying to figure out which color wire goes to which Terminal on the Relay and which one goes where on the BWM. The flash in your pic washed out the color so the Yellow & White are confusing and I don't see the Red anywhere.
Sorry! My resident Electrician Buddy I'd usually ask dumb questions like this, has been working in Afghanistan for the last year.

http://i.imgur.com/ltcCSjI.jpg
Click to expand...

The wire color on the relay end of the wires is of no concern - it's just whatever color your relay harness plug has. Just make sure that on your relay the wires run:

Bosch Relay connector layout:
LID4nSu.jpg


Terminal 30: 12v+ unswitched power from power distribution post (brown wire in pic, but I think you said your new wire is red).
Terminal 87: wire connects to the C19 connector, the two wires (blue with stripe and pink) on the harness side (new wire has male spade terminal).
Terminal 86: wire connects to the C19 connector, the single blue with stripe wire on the switch side (new wire will have female spade terminal)
Terminal 85: ground wire to chassis - I used a ring terminal on the other end and attached it to the heater box mounting screw

That should handle all your relay wires. The other 3 wires (brown, black, red) at C19 just need jumper wires to connect them together as if they were still plugged into each other.
 
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Thanks, But Guess I Wasn't Very Clear

I'm confused because the Diagram on the Relay looks like an "H" laying on it's Side, But the terminals are in a + formation and I can't tell which one is which Number terminal.
The Wire Colors on the Relays I got appear to be Identical to the one in your photo. That's why I was trying to figure it out by wire color.
 
Thanks. Just What I Needed to Know

Now my Feeble mind can comprehend what I'm looking at.
I bought 4 of the relays because I have other places to use them on other cars.
 
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