I'm thinking about replacing my wiring harnesses. What circuit should I use? 12 or 18?

 

Huh? They make nice aftermarket factory style replacements. They are well worth the money.

 

Agreed. A repro wire harness will be the correct colors, wire gauges, and terminals and is basically plug and play.

Time you go thru all that rewiring you'll wish you'd bought the repro.

If you DIY, you need to match up the new wire to whatever gauge the original is. Oldsmobile wiring circuits typically use 16 gauge wire except for charging system and main power feeds which are usually 10 or 12 gauge.

 

Go with the repro... M&H or ron Francis...you wont regret it

 

The generic "painful" wiring harnesses are one-size-fits-none. I've never seen the attraction, especially since you STILL need to cut and terminate at least one end of each wire. That's about as much work as just fixing your original harness. Otherwise, get a correct repro.

 

If your main harness isn't that bad I would just repair it. A new correct one will cost you around 500 just for the main harness. So if need everything you will end up spending over 1,000. A painless harness you will spend more time and money then just repairing your old one.

The only ones that I would replace would be the one's under the hood.

 

Ask anyone that's had an electrical fire, and they'll tell you they'd rather have spent the time and money than watch their car go up in smoke!
Insurance or not, it's a hell of a feeling, especially if it could have been prevented!
Just look at the antique section of Copart if you don't believe me!

As most of our fathers told us, "do it right, or don't do it at all"! [at least mine did!]

 

I've used both Painless and American AutoWire kits.
Painless sucks for newbies. American Autowire is highly recommended on almost
every Pro-Touring board you will come into contact with. Their harnesses
are the best out there besides the very expensive fancy pants ISIS stuff.

2 things make American AutoWire better then Painless IMO.
#1. Every wire is labeled the ENTIRE length with AAW. - Painless does not.
#2. Every AAW kit comes with SEVERAL subschematics for sections of the harnesses to install - Painless does not.

I just rewired my entire '78 z28 front to back with a new American Autowire Highway 22 kit.
It ran me $400 for the harness for everything in the car. MIND YOU this isnt the stock fuse block style!!!!
Most of it was plug and play except very minor sections.
Like the tail lights , it didn't include NEW bulb housings.....but most don't.
I made custom LED housings for this car anyways, so it didn't matter.

Mind you they ALSO have the OEM Factory Fit kits for over $500 which are straight plug n play.
http://www.americanautowire.com/factoryfit.html
however.....you're stuck with just the 12 circuits that the factory created.
If you go with a custom kit, you can split circuits or add them.
http://www.americanautowire.com/highway.html

You can see I had my Painless harness gutted because the idiot that installed it botched it up.
http://www.nastyz28.com/forum/showth...y+Gets+Rewired

Mind you mine is a COMPLETELY custom install matched up to a modern Gen III GM LS1 drivetrain.
Here's what the American Autowire subschematics look like. They're idiot proof.
AAWHwy22Schematic3.jpg
AAWHwy22Schematic5.jpg

 

I spent the money on the stock American Autowire harness and couldn't be happier. They refurbished the dash harness for a fraction of the cost of a new one and replaced all of the rest with new. As long as the previous owner didn't hack up the dash harness, this harness does not get a lot of abuse from weather or heat and was inspected, cleaned and retaped if needed. All factory mounting clips are installed on the new harness.

Dave

 

check out REBEL harness's if your after a non original replacement. if you check on the HAMB you will see they have a good rep. small american company and they are made in America. I bring them in to OZ and have sold a fair few, people couldn't be happier.

a 20 circuit will set you back $200

http://www.rebel-wire.com/wirekits.shtml


if you have the ability to read and follow colours and take your time , you could rewire your car in a weekend without too much trouble..

if you want the stock look then obviously a OEM type harness is the way to go.

 

At a glance, it looks pretty decent......however.....

I'd have to see what gauge wire they are using for the circuits to see if it's a value or not.
But if they are using the proper gauge wiring over the right distances, they might be a worthy option.
I know with German made vehicles MAD Electrical told me they always use too small of a gauge of wire.

I wonder if they actually include a good schematic to use to install it.
If they do, hell that's a budget builders dream right there. Might not be for amateurs though.

 

Do the repo wiring harnesses use aluminum wires like the original harnesses in the 70s? If so, that is bad news...

 

"Painless" is an oxymoron...
American Autowire has had a pretty good rep. I heard one big issue by someone on this board, but the problem was remidied to his satisfaction.

I have not seen any AL wiring in any of my 70's cars... Any particular models you saw them in?
I doubt AL wiring would ever be reproduced just for liability reasons, let alone its other drawbacks.

 

Only place I know it was used was in the flat conduit on the floorboard running to the back of the car. Seems like I've seen some stuff in the Service Guilds about repairing it.

 

I believe GM used aluminum wiring in their vehicles sometime during the 70s.

 

I've never seen aluminum wires used in any 70's GM vehicle.
I have seen tin coated copper wires available, but never from the factory.

All the painless and American Autowire stuff is definitely copper stranded.
I laughed at the "Painless is an oxymoron" because she's spot on with that comment.

 

Good info!! Thanks!!

 

I have a 67 cutlass and bought my harnesses from OPGI/ M&H wiring they seem to be a darn good choce, but the fella's are correct, i'm scared of fire so I'm going for plug and play. My car's had mice in it for over 15 years. I'M GOIN/SUGGEST NEW is the way to go