Mike... This 5 pack of relays that Greg posted...
is a great deal offa Ebay...
http://www.ebay.com/itm/5-Pack-30-4...2-Volt-Bosch-Style-SPDT-PREMIUM-/351153131033
You will actually NEED at least these 5 for the basic mods that are essentially REQUIRED for a '79.
Two for the WSW mod, Two for the Headlight Relay Mod (HRM), One for any kind of good CD player and/or amp and woofer. The Brown Wire Mod (BWM) is also needed but does not require a relay. (Named for the wiring color, but Bob Brown has the BEST suggestion on how it should be done).
I suggest that you purchase these relays, also a Fuse Holder to accommodate at least 6 fuses (any type of fuse, your preference, but late model types are preferred and fuses are easy to come by).
Lastly... you don't haveta do it all at once... but finding a good spot to mount this stuff (usually under the front hood where it can be easily serviced if needed) and the re-wiring for the BWM, WSW, HRM, Stereo, etc. can be done one circuit at a time. If you do undertake this all at once... I suggest STRONGLY you test each circuit upon its completion... and test all circuits again as you progress, ensuring you are screwing things up as you move on.
Lastly... (again) Purchase wiring, connectors, fuses and stuff from either eBay or wherever... But also order a set of TWO or THREE Air Horns from Harbor Freight for 15 - 20 bucks and install them as well. They are a SAFETY MUST... and even though others cannot see you... they will MOVE AWAY from the sound they make. Trust me on this one!
http://www.harborfreight.com/12-volt-super-loud-air-horn-40134.html
http://www.harborfreight.com/three-trumpet-12-volt-air-horn-set-with-compressor-94862.html
(Wire these in parallel with the stock horns, a light tap on the button will say "hello" to friends, leaning on the button will tell others to STOP TEXTING and GET OUT OF YOUR WAY... NOW!)
Great talking to you yesterday... enjoy the Air Races in Reno... and stop HERE on your way home:
HARBOR FREIGHT
2749 N CARSON ST STE 150
CARSON CITY, NV 89706
or HERE while in Reno
HARBOR FREIGHT
3800 Kietzke Ln #150, Reno, NV 89502
Other things to get at HF are...
http://www.harborfreight.com/150-piece-terminal-and-connector-set-67683.html
http://www.harborfreight.com/catalogsearch/result?q=fuses
Three
RADIO SHACKS in Carson City
https://www.google.com/search?q=rad...la:en-US:official&client=firefox-a&channel=sb
Relays are available here:
http://www.radioshack.com/product/index.jsp?productId=42683836
O'Reillys Auto Parts have the MOST stuff available (electrically) over all the other Brand-Name parts stores that I have found...
Two stores in Carson...
https://www.google.com/search?q=o'r...la:en-US:official&client=firefox-a&channel=sb
Their website and in store computers are a BITCH to use and locate parts. Just go to their electrical section and look for wire, fuse holders, fuses, relays and terminal connectors.
Hope this all helps... no more excuses!
HA!
Oh... and if you can, SEARCH for a manual like this for your year...
http://www.ebay.com/itm/FIAT-Servic...anuals_Literature&hash=item43ced026d8&vxp=mtr
I've found them easy to use and they separate the circuits nicely.
Found this one here and it is what I have...
[ame="http://www.amazon.com/Fiat-128-X1-1971-1979-Manual/dp/B000JME6IG/ref=sr_1_2?s=books&ie=UTF8&qid=undefined&sr=1-2&keywords=clymer+manuals+fiat+x1%2F9"]500 Service Unavailable Error[/ame]
But its currently unavailable.
This is curious though... and might be worth a try...
[ame="http://www.amazon.com/Fiat-128-X1-1971-1982-manual/dp/0892872829/ref=sr_1_1?s=books&ie=UTF8&qid=1410028565&sr=1-1&keywords=clymer+manuals+fiat+x1%2F9"]Fiat 128 & X1/9, 1971-1982: Shop manual: Mike Bishop: 9780892872824: Amazon.com: Books[/ame]
Cheapest is 4 bucks plus 3.99 shipping!