When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
So, I'm looking at the wiring diagram from the 1967 Oldsmobile repair manual and I see a fusible link and what looks like a resistor. Does anyone know WHERE they are located on the CAR itself? Heck, I can't even find the battery on the wiring diagram unless it's an "energizer"!? I can't wait to get my 1967 442 body back from paint and body and then have to install the wiring with this wiring diagram. . .
The engine is on a test stand at the moment. I suppose I need a resistor somewhere in THAT wiring to keep from burning up contact points, right?
From what I know, the resistance is built into the factory cloth covered(?) red wire going to the coil. If that wire has been replaced then you might need a an external resistor.
Hmm, I may have confused myself even more -- and maybe I shouldn't worry about it. The wiring diagram I had looked at is shown, below. Joe cleared up that the energizer actually IS the battery, since his wiring diagram specifically calls it such! The resistor shows up in both at the same location. I don't see the fusible link called out in the 36/38 series diagram, but it is in the 33 through 86 diagram; and I wonder why it's in the wire going to/from the horn.
Bottom line, whether I understand the diagram or not, I wonder where the resistor is (and I suppose I should wonder where the fusible link is) ON the automobile, itself! 33 through 86 Series
The reason the fusible link is shown off the horn relay is because that wire feeds off the power stud that's attached to it. The resistor is not actually a resistor, it's a resistance wire. It runs from the bulkhead connector to the coil+ terminal.
I wonder why it's in the wire going to/from the horn.
Because the fine print on your wiring diagram says "Horn Relay AND Junction Block". That stud on the horn relay is the power feed junction for the rest of the car. Note that the wire in question runs from the junction block to the fuse box, ignition switch, and headlight switch.
Why? The battery and the alternator both feed the junction block post on the horn relay. From there trace the red wire. It splits into three parts. One runs up to the ignition switch. One runs down and feeds the circuit breaker in the headlight switch. One feeds three fuses in the fuse box.
In case you do not know what a fusible link looks like. You're looking for an object such as this. This is an image from my 1971 CS; yours should look modestly similar.
This
In case you do not know what a fusible link looks like. You're looking for an object such as this. This is an image from my 1971 CS; yours should look modestly similar.
This
Technically, the item in the clear molded portion is the splice. The fusible link is the short section of black wire to the left of it in this photo. The conductor in that wire is a smaller gauge than in the main red wire and thus will melt like a fuse.
Technically, the item in the clear molded portion is the splice. The fusible link is the short section of black wire to the left of it in this photo. The conductor in that wire is a smaller gauge than in the main red wire and thus will melt like a fuse.
You are 100% correct. Additionally, (technically) the wire is enclosed within a rubber/plastic insulation. Wires themselves have no color, the insulation material has color.
I'd want to learn something from this thread i.e. which is the correct wiring diagram for this vehicle? My assumption was Joe's wiring diagram is correct (obtained from the 1967 CSM). Then, YellowStatue stated "the CSM shows a fusible link for both Cutlass and big cars" (which Joe's does not demonstrate). Joe's diagram demonstrates 34, 36 & 38 series while the OP stated his is "33 through 86 Series". The OP (mwbailey) states his wiring diagram is from a "1967 Oldsmobile repair manual" (which may be one in the same as the CSM, perhaps; but, may also be a different manual).
There ARE obvious differences between these diagrams; yet, they are strikingly similar. Wiring diagrams take significant time to develop/create and are of significant importance. I've noted in the diagram (below) subtle changes/differences between the two. Any comments regarding the correct wiring diagram for this vehicle - which is the correct wiring diagram? I'd prefer not to be brow beaten, but simply identify correctness.
Mine does not have the fusible link, however I replaced some wires that were melted back when I swapped engines.
As Chief points out, this is very interesting.I know when I replaced the engine compartment wiring in my car the link had been sacrificed and I didn't see anything to indicate it had been corrected.
I ask this question: The link is a safety feature is it not? And as a consequence, shouldn't all cars have this fusible link? Well, that's two questions, actually.
As Chief points out, this is very interesting.I know when I replaced the engine compartment wiring in my car the link had been sacrificed and I didn't see anything to indicate it had been corrected.
I don't understand why some illustrators do what they do on some of these drawings. Define sacrificed, if it had been blown not correcting it would mean the circuit has no power. I've never seen a link in the wire that is illustrated in the drawing, it had always been in the wire that feeds the cabin on Abodies.
I ask this question: The link is a safety feature is it not? And as a consequence, shouldn't all cars have this fusible link? Well, that's two questions, actually.
.
Yes, a fusible link is a safety item to prevent the melt down of a harness. It acts as a very slow-blo fuse.
Full disclosure, the wiring diagram I posted is not from my 67 CSM, as that book is out in the shop and it's too f'n cold to go get it. I stole that image from the web. As for the second image in this thread, the fuse link in the wire from the alternator to the junction block only protects the alternator. You need one in the wire from the junction block to the fuse box to protect the rest of the car. That's a high-current wire connected directly to the battery.
"You guys just kill me!" But I am encouraged that others have some confusion about resistors and fusible links, too. Of course, some of that may be my mistake. I do have the CSM (I'm not sure I knew that was what it was called, but makes sense for Chassis Service Manual).
The photo of the wiring diagram (at least the "label" IS confusing). Here is a better shot:
The CSM is for 33 through 86 series, but this particular diagram is for 34, 36, and 38. Other diagrams for big cars and for 6-cylinder are in the book, but not Joe's. Now, why mine is different from Joe's I cannot explain. Nor can I explain why his is "Fig.12-1" and mine is "Fig. 12-3", I surely don't know. In fact, my book does not HAVE a Fig.12-1 or 12-2. So you'd think a page had fallen out. However, my Fig. 12-3 is printed on the back of the table of contents for section 12. My CSM is actually coming apart near the front of section 12, so a missing page would not be out of the question, IF I did not have Fig 12-3 on the back of the first page of the section! Of course, this is getting us nowhere in answering questions about where and why resistor and fusible link. I think I'll read the chapter
Just for the sake of full disclosure, here is the horn relay/junction block in my '67 442 -- at least, that's what I think it is (block not 442 -- I'm sure of the latter). My bigger problem is, as I alluded to in the first post, that I might soon get a second '67 442 back from the body shop and I've assumed I could rewire it.
Thanks for your interest in clearing things up and for helping a novice prepare for reassembly.
By the way, I was interested enough in this topic that I walked all the way out to the shop, IN THE SNOW, to retrieve my CSM. Not too many guys from SC, where we don't get much snow, would do that. . . maybe.
^^^^ The '67 CSM shows the fuse link for A body between the alternator and junction block as Joe states, but the large car diagram shows a fuse link between the junction block and the fuse box. My earlier post was only that there was a fuse link. I keep my books in the house. Snug and cozy.
Last edited by Yellowstatue; January 22nd, 2022 at 11:06 AM.
Reason: Add observation.
This has become far easier to understand (under full disclosure). Not that I have ever extrapolated information from the Interwebs to provide information.
SC SNOW - right, we are managing through an ice-storm which is unprecedented. Luckily the power has remained ON - only suffering intermittent outages during the past 16 hours.
^^^THIS! If you lift up that round black plastic cover on the stud, you'll see the fuse link is connected there along with the battery cable and the cable to the starter.
Thanks Chief and Joe. This site is a treasure trove of knowledge, that I don't have but want to add to! Maybe I can follow the current (no pun intended) wiring in this 442 and match the one at the body shop to that. Here's one more question: How do you get the round plastic cover on a new battery cable? You'll notice, no doubt, that the one in the photo looks newer than the rest of the items. . . and it's attached with a zip tie.
OK, so I think we've just about killed this one. Is there agreement with sysmtg that "the resistance is built into the factory cloth covered(?) red wire going to the coil"?
The problem, yellowstatue, is that when I'm in the workshop is when I seem to need the book; that is, unless I'm doing a little studying in he warmth of the house. Bottom line, the book is always in the "other" location. I thought I could cure the problem by having a digital copy of the assembly manual in my office (in the house) and a hard copy in the workshop. The assembly manual was no where to be found in the workshop when I was up there today looking for the CSM. Doh!
TOK, so I think we've just about killed this one. Is there agreement with sysmtg that "the resistance is built into the factory cloth covered(?) red wire going to the coil"?
Well, it's actually pink, but this isn't a poll or a public opinion survey. The wire IS a resistance wire from the factory. No one needs to "agree" or "disagree", it's a fact.
Got it, Joe. And as I was writing about the assembly manual, it occurred to me to take a look. I think all questions except how to get the round plastic cover on the battery wire to the terminal have been answered. Here's the fusible link, as suggested:
I may have other questions with the body arrives for reassembly
This is an interesting view. Note that the wire with the fusible link Red Main Harness Feed, which is the wire I pointed to back in Post #3. The Engine Harness Feed is the one that comes from the alternator, which is the one shown to have the fusible link in the wiring diagram.
Additionally: (1) I don't believe that huge round black plastic cover on the stud (held on with a zip tie) is original. Original covers were much smaller; and, (2) note the color of the wire leading into the fusible is BLACK. Since we all appear to understand the purpose of a fusible link, note the wiring diagram does NOT call out a BLACK wire w/in the the wiring diagram for the fusible link. See Joe's correct comments in Post #13 ("The conductor in that [BLACK] wire is a smaller gauge than in the main red wire and thus will melt like a fuse.") Note the NOTE on the wiring diagram page (top RH corner): "All wires are 10 GAUGE unless otherwise specified. I can't read the specified wire gauge on the red wire which contains the fusible link; however, it is called out which implies it is NOT a 10 GAUGE wire.
My comment: Someone wired in the fusible link based upon a later model year wiring diagram - at least later than 1968 model year since 1968 model year has a single red wire not a red + black fusible link splice. Again, you can see my fusible (splice) link demonstrates a correct black + red wire of two different sizes which is correct for the 1971 CSM wiring diagram (as noted by Joe's comments which are correct). The buggery of it all.
Last edited by Vintage Chief; January 22nd, 2022 at 03:22 PM.
January 20th, 2022, 06:02 AM
