VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1916-1922 - Model 490 1920 490 Wire Harness

I'm thinking about the best way to replace the wiring in my car. The original wiring is cracked and deteriorated with bare copper showing everywhere. It's a wonder this car didn't burn up.

YnZ carries new harnesses for 490s, but they only list stainless steel conduit for 1918. The other model year harnesses are covered with fabric with an asphalt-like coating. My 1920 has stainless conduit. I called YnZ about this, and they claim they hadn't seen a 1920 with conduit. But if I ship them my wire harness, they can duplicate it. The downside is the harness in conduit is $438 vs $184 without. I guess I have to decide how original I want this car to be. Another option would be to thread new wire through my old conduit, but that sounds like a lot of work. And the "stainless" conduit is rusty.

My question to everyone is what type of harness covering does your car have? I'm wondering if mine is an oddball or typical.

Your car doesn't have stainless conduit. It is zinc plated steel or possibly made from "Ternplate" the same stuff the gas tank is made from but thinner. You will find some places that say they have the right stuff may have used a car that had the wrong stuff as a sample. I think it might be easy to rewire using your old conduit if it isn't too rusty in the joints. Since there is already a wire inside, it can be used to pull the new wire through. On my car some of the places where the conduit joins other conduit or something else like the metal cap for the headlight plug is soldered and can be unsoldered to access wire inside. There is no asphalt loom at all in my car, it is all flex conduit as is the wiring on Dads car as well. I guess I am lucky as all the wiring in my car is original and in very nice shape. One nice thing is, there are not a lot of wires to deal with. Some people have an armored wire listed for some year headlights with one conductor including Y&zs, don't get that either, it is for the later cars and looks like lawn mower throttle cable or at least the original does. The new stuff is flat thin steel wrapped around the conductor wire not round wire wrapping like was original. It might be possible to get the original style conduit at Lowes or an electrical supply shop. The only limit would be is if they still have that small diameter.

Solan has metal conduits, but I cannot tell which metall for sure. Another thing: Use as thick wire as it is possible to get through the conduits. This because you need thick wire to get the 6 V current "running" as good as possible.

The light from Solan's headlights is so weak that I normally avoid driving in the dark.

Bob - I suppose you're right about the conduit being galvanized. I'm trying to poll 490 owners to see if asphalt loom was used on any model year. If Solan's '16, your '21, and my '20 are all in conduit, I suspect all 490s are. I'm thinking YnZ is full of it.

I'll pull the harness out of my car to see if the conduit is salvageable and to measure wire lengths. I don't like doing wiring jobs but I can probably force myself to save a chunk of change.

One thing I will need help with is routing of the wire conduit. Only the engine and dash branches of my harness are hooked up. The rest is zip-tied in a bundle under the hood. I have no idea how the head & tail lamp harnesses are supposed to be routed.

Don,

The wiring on my '17 is cloth covered wire in conduit. It is not that hard to replace the wire in the original conduit. As Bob has said, you can use the original wire to pull the new wire through. It is time consuming, but the 490 wiring is very simple. The hardest part I had was getting two lengths of wire through the tube on the steering column for the horn button. It is a tight fit. You can get black cloth covered wire from Lang's. It is definitely a lot cheaper than your other two quotes, but like I said before, time consuming. There is a sense of pride when you're done that you did it yourself.

regards,
Gary

Have you tried Rhode Island wire http://www.riwire.com/

My '18 490 has wiring in conduit as did my '19 FB. I still have some of the FB wiring harness and yes the conduit is galvanized. Also have the original battery cables around here somewhere.

My '16 is in galvanized conduit, too.

Chipper - I'd be interested in seeing a photo of your original battery cables. Mine are not original, and I want to make up new ones to look original.

So far 1916 through '21 490s are confirmed to be in metal conduit. I'll let YnZ and The Filling Station know that. Maybe they'll change their catalogs - or better yet - their wire harnesses.

Rhode Island Wire doesn't list a wire harness for my 1920 490 - only 1916-18. RIW does offer lots of wiring supplies though - metal conduit, fabric-covered wire, battery cable, terminals, etc.

I will try to get pics of mine today when I try out the new clutch collar.

I'll try to get a couple of photos.

FYI, flexible metal conduit is available http://www.delikon.com/yf_703.html is one website I found when I googled it.

Were the original 490 battery cables in metal conduit? Anyone know the wire gage?

Also, can anyone tell me where the junction box was fastened to the car and whether the box had a cover? If so, how was the cover attached? Mine is just an open metal box floating in air.

I would not think the original battery cables would be in metal conduit, but I never saw an original one.

The junction box should be on the inside of the left frame rail near the carburetor if my memory serves correctly. I think the bolt that held the box (which is just a cover held onto the frame rail, I believe) is 1/4 - 20. I don't remember the length, but you can measure the box plus a 1/2" or so.

regards,
Gary

Gary - If I understand you right, the open box didn't have a cover, but was bolted open-side to the frame - so the frame closed the box. Never thought of that. I'll look for a 1/4" hole in the frame.

I'm trying to order parts to remake my harness. I can maybe reuse the junction box if I can get it straightened out and replated. I'm not sure, but I think the conduit was attached to the box by inserting a bushing from the inside and soldering.

Information that would be helpful to me is how the conduit is routed to and attached to the head and tail lights. Also, how much wire extended beyond the conduit. My harnesses were cut off and tied in a bundle.

The headlight wires have two separate conduits leaving the junction and going to each headlight. I think my car has at least one original battery cable on the positive side.I saw in the parts book that 20 uses a different cable set up, May have changed when the battery box changed. Mine has a regulat style end and cloth covering and aprox 0 gauge. 6 volt systems must have large dia cables to run the starter correctly We have a sunny day here so I will finally try to get the car outside and get photos.

The BOSS is supposed to take a picture of one of the two original battery cables. It has conduit on approximately 2/3 of the length and an offset terminal end. The conduit is held in place by friction tape.

I am currently not home so can't do much except for describe from memory. Have the other cable and most of the wiring harness at the storage building which I will visit on my way home. Should be able to either take the photos or bring the parts home with me. Don't plan to be home before Saturday.

Don,

Yes, you have it correct. If I remember right the conduit was attached to the box, but my box was just painted not plated. Hope this was of help.

regards,
Gary

There is a wiring diagram in the back of the Repair Manuals. There is also a small book that covers all electrical for the 4-cylinder engines (and the V-8).

One of the best reference books you can own is any of the several books "What Every Chevrolet Mechanic Should Know". There are several dates on these books. The one dated 1928 provides excellent coverage for all pre-29 Chevrolets.

The parts manual here will have pictures of your wiring and the repair manual at the same location a wiring diagram.
http://www.reginaantiqueauto.ca/tech_library.htm

I have several 490 wiring diagrams, one of which mostly matches my car. I'd be interested in finding a copy of the "small book that covers all electrical for the 4-cylinder engines".

I pretty much know where the wires are supposed to go. Now I'm trying to nail down what the wire harnesses are supposed to look like. Things like construction, harness routings & lengths, etc. Like I said, my harness was cut off and zip-tied in a bundle so I can only guess where it was routed and clipped.

For example, the metal conduit to my tail lamp is 3 ft long. Judging by the picture in the Parts List, it looks like it should extend all the way to the tail lamp. Assuming that's correct, the conduit length depends on the routing it takes to get there.

I also have no idea how the two conduits were routed to the headlights.

I will try to find the sketch enclosed the wiring set I bought, made by Egge Machine many years ago for 490s.

Coming back if I find it.

One more thing: I haven't seen a wiring diagram that lists wire gauges. So I'm trying to guesstimate wire sizes based off what's left of my harness. Has anybody seen 490 wire sizes listed anywhere?

If youre still looking for the conduit, in either stainless or galvanized, www.brillman.com has it, and lots of different types of cloth coated wire made just like the original. I use their stuff when I do restorations on my tractors. The wire looks GREAT.
Frank

I found the sketch. Have emailed it to you.