Using the fuse block, service manual or owner's manual, make a list of fuses for this car. Get whatever type the books call for and don't substitute- the engineers had a reason for using an SFE type fuse vs an AGC.

Also get a plastic fuse puller to remove and install them.

Alternately you can DISCONNECT THE BATTERY and use a small screwdriver to pry the fuses out of their clips. While the fuses are out clean the clips with a wire brush.

Here's the 66 Toronado fuse block and fuse specifications out of the service manual.

 

Thx for that pic

i wonder why it says 30 on the dome fuse when the box says 20, and 15 for the tail light when the box says 9?

 

yeah it says 50A for some reason
Which side is the load side and where do I find the orange wire?

 

Go by what the printed legend to the side says. All 1966 Olds from F85 thru Ninety Eight use the same fuse block with the actual fuses spec'd to the carline, no matter what's printed on the block cavity.

Take the courtesy light back off the dash and you'll see the orange wire. That's the 12v source. The white wire goes to the dome light switches in the door jamb and is the ground side of the dome/ctsy circuit. When the switch plunger extends out, it completes the circuit and the lamps come on.

On your fuse block, the fuse clips near the outer edge are the feed side.

 

88/98 fuse block


F85/Cutlass fuse block


You see the fuse blocks are identical. That's why you have to go by the CSM specs when replacing fuses.

I'm not trying to be snarky or cruel here, but I honestly think you're out of your depth with this car. To own any old car now, and especially an advanced engineering for its time car like a Toronado, requires some mechanical and electrical savvy. One to be able to do minor service yourself, and two to be able to explain to a service tech what's going on if the repair is beyond your capabilities.

We've done everything but come fix it for you. Use your CSM and electrical troubleshooting tools to attack and resolve the problem. If you have doubts as to your ability, find someone who's comfortable with automotive electrical work.

 

Found the book, here's the electric diagram, quite a lot to squeeze into a small space

 

I rotated your diagram. There are no fusible links on your car. Check your voltages at the fuses and let us know what you find, we can direct from there.

 

A test light is one of the most simple most useful tools ever for electrical issues. You ground the clip side to a good ground. Stab the wire. It will light up if there is electricity in said wire. Someone stuffing a fifty amp fuse in there is a definite sign. You will have Zero fuses at fifty amps. Sounds like someone had an issue before. Very hard to diagnose electrical issues over the internet.

 

Yeah it says 50A UK on the end, strange 🤥

can I use the test light to check the fuse box terminals as well?

 

Yes

 

Just chiming in on ‘66’s again for a sec. Lots of Toro electrical design & big car designs are similar. Here are some thoughts:

For the big cars (88’s, 98’s, Starfire), the Chassis Service Manual (CSM) fuse specifications vary a bit from the ‘66 big car Factory Assembly Manuals. The factory assembly manuals specify 30 amp fuses in a few places where the CSM shows 20 amps depending on what optional electrical equipment is added to the car. Like 30 amps on the A/C heater circuit, if A/C is installed, or if rear defroster is installed. Or like 30 amps instead of 20 if power windows & power seat are installed. Or 7.5 amps for an AM single speaker adio vs. 9 amps for AM/FM with reverb with rear speaker.

50 amps in a glass fuse is way beyond the pale. It clearly indicates someone had problems in the past. Someone wanted a really big band-aid and didn’t want to fix the problem. Assuming someone didn’t want to trace out the problem, the less wrong move here would have been to put in a circuit breaker. But o.k., at least you have some “car”-cheological signs about the problem. The right move here is find & solve the short.

The job now is to find the junctions and disconnect them one by one until the problem is located, then fix the errant wire.

Cheers
Chris

 

Why would you call it a short? If it were a short, the fuse would blow or things would begin to smoke. Perhaps the previous owner stuck the 50amp fuse in there because that's all that was available at the time. Who knows why things happen. As to the OPs issue, apparently the car was operating fine until his latest repair attempt.

 

British (UK) fuses esp LUCAS are rated differently than US-spec fuses and, like a lot of LUCAS stuff, is confusing.

I also think someone stuck whatever was at hand in the fuse clip to get the car operable.

Were the car mine, I would replace all the fuses with what the CSM specifies.

 

It was, until I put that stupid bulb in there. Probably why there are no under dash courtesy bulbs in there since I've had the car. Some things you just can't predict

 

Not sure if this has anything to do with, but there is this black wire on a washer that was screwed in with the courtesy light socket, is this some kind of ground wire?

 

Don't know can you find the other end?

 

Dont know it goes up in the dash somewhere. Is this a factory setup? I think the light socket already had a ground wire attached to the back

 

Ok, did the test light thing, no light on those 3 fuses. I did get a light on the wiper fuse, just to be sure it's working.
What would be the next step? Can I use the light on the junction block where that red wire is attached?

 

Yes, use the light to test power at the horn relay stud. The red wire is what brings power into the harness inside the car, so You will almost certainly have power at the horn relay. The red wire branches off in the harness There is a branch going to the fuses in question, a branch going to the ignition switch, as well as a branch going to the alternator and voltage regulator. If you have power at the wiper fuse, the branch going to the ignition switch must be good, that branch is what powers the ignition and accessory feeds in the car. When you were testing the lower battery fuses did you touch/ scratch the terminals on both sides, or just touch the fuse itself?

 

i did both the terminals and the fuses

 

Where the red wire splits off to the different branches (headlights, ignition switch, fuse block, alternator, etc). It is possible that the branch feeding the fuse block broke away from the rest, or that the terminal seen on the back (shown in the photo I posted earlier) fell off of the main fuse terminal.

 

This is what your issue sounds like by your description.

 

 

About that "Shunt splice" where all the wires come together from after the junction block, does anyone have a pic of what it looks like without the tape around it? I would like to see it before I go pulling the tape off if possible

 

I don't have a pic on hand it is basically a large solder joint where all of the wires come together. Once soldered, the joint has a special (thicker) tape put over it for a couple inches on each side of the joint and then it is wrapped with the rest of the wires in the main harness.

 

So it would be difficult to unwrap/wrap back together again?

 

Found this piece with an intermittent (rusty) connection, anyone know what this is? Im talking about the small rectangle piece with the bracket that's screwed into the junction block, has 1 terminal with a black wire coming from it

 

It is not too difficult to wrap/ unwrap once you get to joint, but if the harness is still in the car it can be difficult to find the joint in the first place. Once you do find it, you have to get it pulled out from the rest of the harness to examine it. The small box bolted to the horn relay stud is the main power circuit breaker for the power windows and power seat. Do you have any other pics of this area from slightly different angles? It looks like there may be 2 circuit breakers, but it is hard to tell in the pic.

 

That looks to be a circuit breaker. The splice your looking for is under the dash.

 

i think it's the only one as far as I can see. Is the rubber block next to it with the red wire another circuit breaker?

 

Under the dash? Where would that be located?

 

The main 12 junction is not visible under the dash, it is inside the main harness.

 

12 junctions? Yikes 🤥
Thats in that Union area near the horn relay right?

 

Sorry, typo. I did not mean 12 junction (12 wires) I meant the wire gauge size (10 - 12 gauge wire). The solder joint where these wires connect together is nowhere near the horn relay. It is inside the car under the dash in the main harness that comes off the fuse box and is not visible by simply looking under the dash. It is wrapped in the main harness along with the rest of the wires. The photo below shows my harness when I was restoring it. The blue circle is the area where the fuse box goes. The red circle is where you will likely find the junction that connects the main 10 gauge wire for the fuse box, headlight switch, and ignition switch. The yellow circle shows the area where the 10 gauge junction is for the alternator, voltage regulator, horn relay connection, and the wire going into the car to the other connection (red circle).

 

He means 12 gage wire. Your CSM wiring diagram shows 6 wires connected at the shunt splice. 5 red, 1 black (goes to dash ammeter).

That's why it's called "shunt splice"- it "shunts" current load thru the ammeter and back to the junction block to indicate charge or discharge conditions, without running the car's whole electrical load thru the instrument.

 

As rocketraider said, the addition of the ammeter on a 66 means that the shunt splice location might be in a single area unlike my harness that has two separate junctions. Either way, you will not find the connection by simply looking at the harness from the outside. It has to be unwrapped. The next easiest step is to pull the fuse block away from the firewall and test the red wire going to the fuses in question to see if it has power going to it. If it does, your problem is simply a connection issue (corrosion) if it does not... it might be a bigger job than you want to tackle.

 

Is this the shunt in question? Has quite a few wires all connecting together. Near the AC box under the hood

 

No, that is merely an area where the harness splits off into different areas of the car. Just curious, is your car still displaying the issues you originally stated? Have any been resolved? Can you list one more time exactly what is working and what is not. Which lights still come on? Does the car start? Do the gauges work?

 

Still the same problem, no stop lights, rear parking lights or interior lights. Headlights, front parking lights, radio, wipers, and both front/rear turn signals all work, as do the green dash turn indicators. Haven't started it the few weeks since, so don't know if it will start or not

 

Does the glove box light work? If not, did it work before?