Help - Electrical Gremlins

[hunt2elk]

Here is a color pic of the ammeter wiring. The junction on the black wire out of the meter is a soldered, taped factory connection.

 

[Stumper]

Here is a color pic of the ammeter wiring. The junction on the black wire out of the meter is a soldered, taped factory connection.

View attachment 1617794

Hunt2elk, any chance you could scan that entire diagram and send it to me?

 

[hunt2elk]

Hunt2elk, any chance you could scan that entire diagram and send it to me?

I believe so, pm me your email address.

 

[khryslerkid]

Can someone help me understand what I’m looking at here. On the wiring diagram- R6 is heavy black to the bulkhead. R6A is heavy black to the amp meter. Q3 is red/wh stripe to fuse box and J1 is red to Batt on ignition switch. L1 is black to headlight switch.


Is this showing a junction of all of these connections?? The second black wire that was on my amp meter is a junction of headlight, fuse box and ignition wires.?? If I’m understanding correctly the second black wire should be ok like this?

View attachment 1617782

 

[Stumper]

View attachment 1617892
View attachment 1617893
View attachment 1617894

The bulkhead and relay look like mine (except your wiring looks new). The dash is completely different.

 

[khryslerkid]

The bulkhead and relay look like mine (except your wiring looks new). The dash is completely different.

Just showing you the amp guage wiring. The extra green wire is for the center console. They used a inline fuse in the kick panel.

 

[Stumper]

I think here is unanimous agreement that I have a major short. Trouble is finding it. Did my attempt to check continuity at the amp gage show anything? Did I do it properly? I checked each post to the dash frame with all wires detached and the dash on my lap. My meter read OL on both posts - but also read the same on the old dash gage that was working? Both gages show continuity between the posts?

 

[Stumper]

Just showing you the amp guage wiring. The extra green wire is for the center console. They used an inline fuse in the kick panel.

What’s the heavy white wire on the red terminal?

 

[khryslerkid]

What’s the heavy white wire on the red terminal?

It's actually light green. It's for the console, cigarette lighter and courtesy light. They use a inline fuse behind the kick panel. That's how the factory did it.

After installing your new wiring check continuity from start to finish before hooking up the battery.

Unplug your bulkhead connector and inspect for any melted terminals or a place where something might have grounded between terminals in the plug. Good luck.

 

[69_A12_6BBL]

The two things I changed was adding a mechanical oil pressure gage and wiring up the light in it. It was wired to a switched hot with no switch on and there was no sign of heat or damage. I also added an oil pressure sending unit for the idiot light and again no sign of line damage. These were the only electrical changes I made while the car was down. The new dash panel I put in was wired the same as the one that came out.
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Did you perhaps Connect to "Batt+" FROM the Alternator along the way? Instead of connecting to fuse block 12V "Hot in Run" circuit? If so, that's gonna send AMPS over Volts, & Will cook a wire.

 

[69_A12_6BBL]

What would I check with the amp meter (remember I suck with electrical).The red hot wire goes to the terminal marked Red on the panel for the gage and two black ground wires that go on the terminal next to it. Could the gage itself be grounded out internally? How can I tell?

Ammeter has nothin to do with what your dealing with. That's only a Hot wire from Alt. That comes OUT of the Ammeter (Black) & splits off into the fuse block & Ignition. I'm bewildered by those that "Bypass the Ammeter".. lol It sounds like you have possibly received a "Bad" or internally shorted guage, or tapped into Charging system. A "Short to Ground" will ALWAYS overheat until voltage stops. Think of electricity like a flowing river. When it hits "Resiatance" it's like a Dam does to a river.

 

[69_A12_6BBL]

Didn’t get around to pulling the dash today to check continuity but I plan to do it. I made up new wires today while a buddy crawled under the dash. He didn’t find any burned or damaged wires and confirmed that they were on correct terminals.
My SM diagram shows the red terminal wire on the amp gage going to the bulk head connection to pick up power from the red line coming in at the fire wall - the one that burned up. It shows one black wire from the other terminal that goes to the bulkhead to pick up a black wire that runs to the alternator. I still haven’t figured out what the other black wire is for that is on the same amp gage terminal but did find that it splices into a green wire …. Still need to trace some of these wires out.
That said, what ever the wires go to they were attached to the old dash panel the same way and it worked fine. So maybe I’ll find that the amp gage itself is bad and can get it replaced.

A couple of how to electrical questions. Since the wire from the starter to the relay and from the relay were burned to a crisp, is it likely the relay is also toast? How would you test it?

If a starter is shorted out internally it wouldn’t work on a bench test would it. Could the short that bad come and go in a starter?

When checking continuity of the amp gage terminals is it ok for the dash panel to be removed since you are going terminal to frame anyway?

Thanks in advance for the help!

You have 2 BLACK wires coming FROM Ammeter "Neg" side? Thats not right.

 

[A4GTX]

There is an inaccuracy in your post. There is no hot wire from the starter to the relay. GM does that but not your Mopar. The large positive (hot wire) cable goes from the battery to the starter. The smaller wire on the starter is from the relay to the starter and is only hot in the ignition switch “crank” position. If that wire burned all the way to the starter, then it indicates that it was getting the hot feed through the starter solenoid or the two wires were touching at the starter, since it wouldn’t burn if it wasn’t carrying current. But it shouldn’t have been carrying current if the ignition switch was in the “off” position (or “run”), unless the relay was shorted to ground. That could have burned both of the wires you say were burnt but the two wires would have had to be connected, somehow, at the starter. This is an odd one! I would replace the starter relay and burnt wires, then hook up the battery and monitor, ready to pull the cable back off.

 

[Sixpactogo]

You have 2 BLACK wires coming FROM Ammeter "Neg" side? Thats not right.

There is no "neg" on any ammeter. Both are Pos. Black from Alternator, Red from Battery. Any negative wire on an ammeter would be a dead short.

 

[BigFlo]

I think here is unanimous agreement that I have a major short. Trouble is finding it. Did my attempt to check continuity at the amp gage show anything? Did I do it properly? I checked each post to the dash frame with all wires detached and the dash on my lap. My meter read OL on both posts - but also read the same on the old dash gage that was working? Both gages show continuity between the posts?

This is correct. Your ammeter posts should be isolated from the dash frame and the two posts should show continuity. Current passes through the ammeter, and in simple terms it measures amperage, not voltage.
There should be isolation washers on the ammeter posts so when you connect the ringlugs to the ammeter posts, the ringlugs do not touch the dash frame - they should only touch the posts.

 

[Stumper]

There is no "neg" on any ammeter. Both are Pos. Black from Alternator, Red from Battery. Any negative wire on an ammeter would be a dead short.

Yea, I got corrected on that early on.

 

[Sixpactogo]

Maybe this diagram will help. It is typical of all of our Mopars.

 

[Stumper]

There is an inaccuracy in your post. There is no hot wire from the starter to the relay. GM does that but not your Mopar. The large positive (hot wire) cable goes from the battery to the starter. The smaller wire on the starter is from the relay to the starter and is only hot in the ignition switch “crank” position. If that wire burned all the way to the starter, then it indicates that it was getting the hot feed through the starter solenoid or the two wires were touching at the starter, since it wouldn’t burn if it wasn’t carrying current. But it shouldn’t have been carrying current if the ignition switch was in the “off” position (or “run”), unless the relay was shorted to ground. That could have burned both of the wires you say were burnt but the two wires would have had to be connected, somehow, at the starter. This is an odd one! I would replace the starter relay and burnt wires, then hook up the battery and monitor, ready to pull the cable back off.

I’m a bit confused, but then again always am with electrical. My set up has the Pos battery going to the starter and the smaller red line to the relay coming off the same post on the starter. I figured that wire to the relay has to be hot coming off the starter hot terminal?

The two burned wires are connected at the relay post. Is the point I’m missing that while the relay is open the two wires are not technically connected?

 

[pnora]

I’m a bit confused, but then again always am with electrical. My set up has the Pos battery going to the starter and the smaller red line to the relay coming off the same post on the starter. I figured that wire to the relay has to be hot coming off the starter hot terminal?

The two burned wires are connected at the relay post. Is the point I’m missing that while the relay is open the two wires are not technically connected?

Post pictures it might help.

 

[Stumper]

Maybe this diagram will help. It is typical of all of our Mopars.

View attachment 1619503

This is a great - simple diagram. Thanks. I will note that my car does not appear to have the fuse-able link between the relay and amp meter, unless it’s under the dash and I just haven’t seen it.