I am in need of electrical assistance

1971 442 4 speed

I have no power to the dash. (no start, no head/park lights, no radio, no heater fan, no interior lights)
According to the Service manual wiring diagram, the battery positive connects to the Horn Relay and Key Buzzer. Both the Horn and the Key Buzzer work.
There are 3 wires from the relay: 1) to generator, 2) to regulator and 3) to light switch, ignition switch and fuse panel.

I have continuity from the relay to the generator: wire 1.
I have continuity from the relay to the regulator: wire 2.

The third wire appears to be my issue. According to the Service manual wiring diagram: there is a fusible link in this third wire. I am "guessing" that this is the cause of my issue.
If my guess is not feasible, where do I go from here?

So, Here is my series of questions:
Where is the "fusible link" in this wire?
Is it at the relay as shown in the wiring diagram?
How to I test this fusible link?
Is it replaceable/fixable?

Thanks for your assistance.

Attached pics:
Pic 1 is the Service manual wiring diagram
Pic 2 is the relay in my 442 (the disconnected wire is wire 3)

 

I'll post a couple images for you in a minute. The "fusible link" is denoted by a "black" wire at the end of the "red" wire connected via a splice/connector between the black wire & the red wire.

 

NOTE: If you find the issue is the fusible link, purchase a fusible link since the outer insulation of a fusible link is different from normal wire outer insulation as it meets safety standards which curtail/reduce the possibility the outer insulation will catch fire.

 

A fusible link should not exceed 9" - typically they're about 6" in length. Generally, the black fusible link wire is four gauge numbers smaller than the wire it protects. Example: A 12 gauge wire would be protected by an 8 gauge fusible link.

 

Fusible link is black wire.

 

Hey Chief

thanks for the info and pics. that is great information.

but, now I’m a little confused. The pic 2 I provided shows my car does not have the fusible link at the relay.

Could the fusible link be somewhere else in the wire? If not, what do I check next?
thanks

 

My apologies. I should/could have been more clear. NOTE: The section of the 1971 color wiring diagram you posted; and, the one I posted is NOT the 4-4-2 wiring diagram. NOTE ALSO: There is a separate 4-4-2 black & white wiring diagram contained in the 1971 CSM (I believe it's the last diagram of the wiring diagrams in the electrical section). I seldom review the 4-4-2 wiring diagram and I should have noted you have a 4-4-2. With that said, I don't have my CSM in front of me so I cannot validate the location of a fusible link in the 4-4-2 wiring diagram. You can check this yourself to see if the fusible link is illustrated in the 4-4-2 wiring diagram.

 

BTW, after you have validated whether the 4-4-2 demonstrates a fusible link, if the fusible link is, in fact, illustrated in the 4-4-2 wiring diagram it will be located exactly as depicted in the diagram. If your car does not have a fusible link, but the 4-4-2 wiring diagram demonstrates the incorporation of a fusible link, you need to install a fusible link. As can happen (frequently) a PO may have deleted the fusible link (mostly because they had no idea what it was for). You NEED the fusible link to reduce the chance of a runaway high energy (HEAT) sink in the wiring harness which w/o the fusible link could cause an engine compartment fire. If there's supposed to be one, install one.

 

Hey Chief

I reviewed the 442 wiring diagram and this area of the diagram is the same. So, my 442 should have a fusible link.

I will have to install one.

but, my dilemma still exists. I don’t have power to my dash.
how should I check for continuity of wire 3?

thanks.

 

Admittedly, I can't see where any of those wires lead to. Perhaps you're leaving something out of the equation here?
There should exist five wires on the Horn Relay Distribution Block - for some reason referred to as the "POWER TAKE OFF" in the 1971 CSM wiring diagram. Suggest you review those five wires. You have a wire from the battery positive (+) post terminal to the Distribution Block?
You have a circuit light tester? You have 12VDC at the Distribution Block? Use a circuit light tester to follow & identify where you do &/or do not have 12VDC.

 

Sorry, I was too busy counting & eating at same time. Should be four wires on distribution block.

 

 

Hey Chief
Sorry I’m interrupting dinner.

Yes 4 wires at the Power Take off.
I have continuity from battery positive terminal through wires 1, 2, and 3.
Wire 1 is battery to Power Take Off
Wire 2 is to Generator
Wire 3 is to Internal Regulator

I am having difficulty with Wire 4
Wire 4 is to 3 connections: a) ignition switch, b) fuse panel, and c) head/park light switch.

It’s time for me to retire for the day. I’ll get out my
Circuit light tester tomorrow and try to move forward.

thanks

 

Connect the battery positive (+) post cable to the distribution block. Use a circuit light tester to find out where you don't have 12VDC. If you don't have a circuit light tester buy one w/ the sharpest point available this allows you to jab directly into a wire anywhere along it's length. If it lights you have 12VDC if not...find out where you last had 12VDC and where you don't - your issue is somewhere in between.

There is one splice & three branches on the fusible link red 12 gauge wire. Start testing.

 

Sounds good. I think the circuit tester is faster & easier use in this situation.

Somewhere along this 12gauge red wire I suspect you'll find the issue - I think that's what you're calling wire No. 4. You can see how a "fusible link" is a good safety component for this branched circuit.

 

I owned a 1967 4-4-2 & a 1972 4-4-2 fifty years ago. I just sold my 1971 CS 350cid convertible. I can't recall, did the 1971 4-4-2 come w/ an internal voltage regulator (VR) from the factory? If so, no worries. If not, did someone install an ALT w/ internal VR?

 

Getting late for me. Perhaps another member can validate if the 1971 4-4-2 came OEM factory installed ALT w/ internal VR. I think I recall somewhere w/in this time period (1971/1972) the 4-4-2 came w/ OEM factory installed ALT w/ internal VR? I know for a fact the CS came OEM factory installed external VR - not internal VR. Just mentioning this in case there might exist the possibility a wiring issue/disparity exists between a factory installed external VR and an upgraded internal VR if someone mis-wired the upgrade? Something to consider I suppose.

Has this car ever had power to the dash since you took ownership?

 

ARE YOU SURE about this ? Shouldn't it be wire gauge number be FOUR numbers larger ? This would make the wire smaller and actually protect the wiring harness.

Tonka442, check your CSM in the "Electrical" section for the correct wire gauge for the Fusible link.

 

The fusible link is in the red wire that runs from the horn relay to the bulkhead connector. The link is sized 4 numbers higher than the wire it's protecting so if you're trying to protect a 12ga you need to use a 16ga fusible link. wire.

 

Oh Geez. You’re correct. I stated backwards. Yes, the wire GUAGE number of the fusible link should be four times higher in gauge number (thinner) than the wire it is protecting. Thanks forpointing this out.

 

No, you still have it wrong. The fuse link wire gauge size should be FOUR NUMBERS higher, (Example 12 + 4 = 16).

Not four times higher. (Example 12 X 4 = 48)

 

Yes it did have power earlier this year. I have owned it for 20+ years without any issues.

 

Apparently, the stars were not in alignment for me when I wrote/typed that post. Yourself as well as Eric were/are spot-on. OMG...I have my moments...geeze.

 

Its not about alignment of the planets or stars ! .

 

Whatever!

 

I'd still use the circuit test light to probe for an open loop.

 

I will be putting in a fusible link.

The wire is 12 gauge.
I understand I need a 16 gauge fusible link.
Is my understanding correct?

Where would you suggest I purchase one?
Is there any particular brand or location that I should avoid?

thanks for your help.

 

Other than a jumper temp backfeeding the fuse panel, that is probably the best way.

 

You can get them at your local auto parts store. You also need to figure out what caused the original one to fail.

 

Try NAPA, Autozone, O'reilly's.
https://www.google.com/search?client...re+16+gauge%22

 

OP state the original failed? OP knows he must install a fusible link, but I've not read which wire is/was the issue thus far.

 

Did you resolve the issue? If so, what was the issue?

 

Here is where I stand:

During the restoration, it appears that the fusible link was eliminated and a 12 ga wire was put in its place. The connection between the new piece of wire (that replaced the fusible link) and the “original “ wire has corroded. The connection (or lack thereof) would not allow for electricity to travel.

I will be getting a fusible link soon and getting it done correctly.

Thanks.

 

Someone installed a supposed "new piece of wire" fusible link (at some point) w/ a 12 GA piece of wire which replaced the original fusible link; and, this supposed 12 GA fusible link you found to be corroded demonstrating an Open Loop (non-continuity) is what I think you said?

So, if you remove this "new piece of wire" corroded fusible link altogether from the equation, you can demonstrate power to the vehicle? Yes, as has been discussed/addressed you know you need a new appropriately/correctly sized fusible link. Yet, keep in mind, as discussed there remains the possibility someone might have had a previous "issue" with that wire...the original OEM factory installed fusible link burned up, or whatever & their replacement was not adequate - this is a guess (obviously). Keep an eye on that wire & its branches. You may still find something remains an "issue" along the path of the red wire which caused the original OEM factory installed fusible link to become an issue e.g. power amplifier, anything amiss with branch wiring in the red wire, etc.

 

Yes, the corroded wire did cause the open loop. I have not fully cleaned off all of the corrosion yet.
I will definitely test power to the dash. The install the fusible link.
I will keep an eye on the wiring.

 

I have installed my fusible link.

I now have power to the dash. So, I’ll watch the fusible link but I’m pretty convinced that the issue is resolved.

thanks for all your assistance.

 

Well done.