Help with no power??

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Veryfastdart

Veryfastdart

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I know this is A body forum, and I own 3 A bodies, but I have a question about a car I purchased this year. 1970 challenger V code. I get far better results on this site than when I ask questions on FEBO. So here goes.
Pulled plugs and oiled cylinders, car has sat since 1983 in a dry garage. Waited a few weeks and slowly turned engine over. Fresh oil, primed it and wanted to try to fire it today, so we put a new red top optima in it, and when I turned the key, NOTHING?
We checked the wiring and I turned on the headlights and NOTHING? It looks like the fusible link going to the stater relay was replaced with a twist on plastic cased 20 amp fuse? I jumped the relay and the car turned over. But I have NO power anywhere?
Any ideas where I can start? I have a good battery ground.
Details on car:
1970 Challenger R/T
F8 triple green car
V code matching number engine
727 non matching
All original sheet metal
Retains almost all original parts
Right down to it’s 15” rallies and P/S oil cooler
NO IT IS NOT FOR SALE!
B3839DE2-6861-473F-867D-729909B6EFF2.jpeg
 
Hot wire it!


Jumper from battery to the side of the ballast resister that would come from ignition.

Use remote starter on the starter relay.

As for the electronic ignition,
jumper from battery to power it.

And fire it up
 
Veryfastdart said:
We checked the wiring and I turned on the headlights and NOTHING? It looks like the fusible link going to the stater relay was replaced with a twist on plastic cased 20 amp fuse? I jumped the relay and the car turned over. But I have NO power anywhere?
Click to expand...
I think everyone was sleepy last night. LOL
So here goes.
Jumping the relay only provides power to the starter. So the battery has juice and the relay works but that's not the issue.
The issue is there is no power going to the power distribution splice.
That's the welded wire splice joining the power sources (alternator and battery) to the power feeds for everything but the starter.
upload_2020-10-3_8-18-9.png


So far from your description the fusible link will be the thing to check.
If it has failed, it most likely failed for one of two reasons.
1. There is a short to ground in the power feeds.
2. It slowly deteriorated due to repeated moderately excessive loads, which could be a weakly connected short, or some other condition that caused repeated high battery discharge and/or high battery charge rates over periods of time.

If there is a fuse instead of a fusible link, that won't handle the charging loads right after start.
Not all fusible links used the flat connector. At some point a round connector that looks like a fuse holder came into use.

IF the fusible link has gone poof! (wire inside burned up), then check for short to grounds before proceeding.
Do this by disconnecting the battery, and use an ohm meter or continuity checker. There should be no continuity between the mains feed wires and ground. Easy place to check the alternator stud ring terminal.
 
If there's no short with the key off, then if there is a short it would have to be in the wiring that is gets power when the key is in Run or Start, but not protected by fuses.
However if this occurs, the ammeter will clue you to this happening. With the engine off, battery connected, turn the key to run. If you see it show more than a 5 amps discharge, something is up. Same with key in Start.
 
If someone replaced the fuse link with a 20A fuse THAT IS TOO SMALL
 
Mattax said:
a round connector that looks like a fuse holder came into use
Click to expand...
'70 shop manual drawing indicates that's what your challenger should have.
upload_2020-10-3_12-46-45.png


?u=http%3A%2F%2Fwww.hiltopautoparts.com%2Fwp-content%2Fuploads%2F2015%2F11%2F3588320.jpg
 
Last edited:
Yup, sounds like the power going from the starter relay to the firewall bulkhead connector has been broken there somewhere. Trace the lead with a test light to see where you have power and where you don't. Might be the fusible link, might be the bulkhead connector, could even be under the dash, or instrument panel. Just a matter of following the current.
 
Mattax
Where does the white end
Plug into? The squared end with the round connector goes to the starter relay I assume? My swinger doesn’t have that so I can’t cross reference to my Chally! Thank you. I will Follow the wiring diagram tomorrow when we get back to it!

Mattax said:
'70 shop manual drawing indicates that's what your challenger should have.
View attachment 1715605778

View attachment 1715605856[/QUOTE
Click to expand...
 
Veryfastdart said:
Mattax
Where does the white end
Plug into? The squared end with the round connector goes to the starter relay I assume? My swinger doesn’t have that so I can’t cross reference to my Chally! Thank you. I will Follow the wiring diagram tomorrow when we get back to it!
Click to expand...
That's the fuseable link and main power supply to the inside of the car. Originally there would have been a wire going to the bulkhead connector that had the other half of that white connector. If the wiring diagram that Mattax posted is accurate, that main power wire goes into socket 16 (one of the red wires highlighted in the diagram). If you follow the wire back, you can see the connector for the fuseable link section, and then the starter relay connection end.
 
Veryfastdart said:
Mattax
Where does the white end
Click to expand...
IF that's the style on you car, there will be a matching white connector that slips in.
upload_2020-10-4_13-22-47.png
But it will be on a 10 ga red wire.
The snip I posted above looks like its from a later shop manual.
hide-gif.gif
I'm looking at '70 now and its not as clear which type of connector it is.
upload_2020-10-4_13-9-13.png


Because its both Chllenger and Dart, they show both possibilities.
One is a red 10 ga. wire from the relay stud to a the fusible link.
upload_2020-10-4_13-16-17.png


The other is ring terminal on the relay directly to the bulkhead connector.
upload_2020-10-4_13-20-4.png


Here's a couple of repop links from Bill Evans. Top one is relay direct to J cavity.
upload_2020-10-4_13-27-43.png
 
When looking at the firewall from the engine side, position of J will be where the arrow points.
The later bulkhead connector shown in the first diagram I accidently posted is pretty different looking.
 
OP Do you even have a service manual? Or a wiring diagram?
 
67Dart273 said:
OP Do you even have a service manual? Or a wiring diagram?
Click to expand...
I have a 70 Challenger service manual I do have those wiring diagrams I just couldn’t figure out why there was no power and I suspected the fusible link
 
Mattax, my factory '70 manual is the same as the one you show in your post#9. I believe it's the most accurate, but, I don't have a '70 E-body harness in front of me. The first diagram you show in post#15 I believe is from a Motors manual or similar. I tend to believe the factory manual over the aftermarket ones. If so, the power off the starter relay would start out with the 16 gauge dark blue fuseable link, go through the round white connector, become a 10 gauge red wire, and plug into socket 16, which, looking at the firewall from the engine side, would be the center bank top left socket. That's at least the place I would start. After 50 years, anything could have happened to change that.
 
Veryfastdart said:
I have a 70 Challenger service manual I do have those wiring diagrams I just couldn’t figure out why there was no power and I suspected the fusible link
Click to expand...

Sometimes I think Mattox overcomplicates. The primary power in these girls is quite simple and failures fall into a small number of possibilities, especially with a major power failure A diagram you would do well to memorize is the one in the MAD article concerning ammeters

Catalog

amp-ga18.jpg


Now people discuss and cuss this article, and I don't agree with some of the "cure" but there are very valid points. The primary power varies some from year to year, but in the cars with "full current" ammeters the path in question is fairly the same

That path, generally CAN FAIL at any of the following points. You simply need to check them all aout

From the battery, to the starter relay "big stud" which is used as a junction. ------from there to the FUSE LINK-----and through the BULKHEAD CONNECTOR on the RED ammeter wire, to the AMMETER----out on the big BLACK ammeter wire and to the WELDED SPLICE.

Each of those points in the path or MORE than one can has and does fail. Even the welded splice has failed in a few cars.

What to do?

Remove the connection to the fuse link and 'work' it and feel for corrosion/ melt damage inside, and inspect the insulation. Disassemble the sections of the bulkhead connector inspect and repair. This is likely one of the most failure prone.

Consider removing the instrument cluster. If not, "feel" up in the ammeter terminals for any looseness, or if/ when you get power, load it with headlights, heater power, etc, and feel for any heating up in there, or intermittent movement of the ammeter needle when shaking the wiring near the ammeter.

The ammeter in the 70 cars is particularly suspect for several reasons...........Severall years ammeters the studs are simply 'slipped' through the shunt/ guts of the ammeter and out through the PLASTIC cluster housing with nuts and washers. IF THIS assembly becomes the slightest bit loose, then it heats and the cluster plastic softens, causing things to get MORE loose, and fail

So far as the welded splice, there is likely no way to check it. If you have checked/ repaird the fuse link, the bulkhead connector, and the ammeter, and still have mysterious power problems, then unwrap the harness starting at the ammeter and follow the black to the splice a few inches away.

IF YOU have the cluster out, I would do that.
 
I don't intend to "sound easy" and parts of this circuit are not "easy" to access but follow the path. It is only two wires,

If you are sure you have power at the INTERIOR of the bulkhead on the RED wire, the next stop is the ammeter.

From the ammeter (BLACK) it goes a few inches to the welded splice. From there power branches off to headlights, ignition switch, and fuse panel hot buss. If ANY of those work, but not all of them, the welded splice has likely failed.

DOES ANYTHING, anything at all work?

Look at the path in that diagram. Put your meter on the big black wire output terminal of the alternator. Any power there? Now turn on the headlights. Does that power go away? You have a bad connection in that path. Just follow it like a road. No difference.
 
ALSO when you checked power "at the bulkhead" OR ANY OTHER TEST...........it is IMPORTANT that you have a load you can apply.........like the headlights.......or even the dome/ courtesy lights. This is because, with everything shut off, there is no LOAD on the bad circuit, and a bad connection can "make" long enough to cause a "good" meter reading.

Have you had the bulkhead connector apart? NO!!!!???? What are you waiting for??
 
67Dart273 is right on the money. Follow his suggestions. You cannot simply check voltage with no load applied (using a digital volt meter). The worse corroded connection will show you 12 volts, but as soon as you apply any load the resistance in the shitty connection skyrockets and your voltage goes away.

Also, if you haven't separated the bulkhead connector you absolutely need to, to clean and inspect all of the contacts. They are finicky.
 
Here is the easy way to fix this in 2 steps .
1) Buy all new wiring
2) Install it

Ok now that we have fixed it how about the story behind the car , equipment list and more pics ?
 
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