...my shifter caught on fire... I cant figure this out...

[Vonzy797]

My floor mounted shifter is Arcing really bad when I hook the ground back up to the battery.
It melted a cotter pin.
here's the rundown.

recently replaced all batter cables and relay - hot and ground. worked really well (this was a few weeks ago).

YESTERDAY - I took the dash out to clean it up and see why my dash lights aren't working. Found my dimmer switch was in really bad shape. (left this disconnected.) Put the dash back in. hooked up the battery. BAM - shifter console is like lightning.
I ripped out the console and removed the cobbled up console light.
Hooked the battery up and played around some more in the car.
Then it did it again. Ive looked all over this car... There are some bad spots/connectors around the harness but I have fixed what I could find. I bypassed the ammeter (just put both connectors on one prong and tightened. This works fine) Headlights and everything work - car cranks.)

Just for kicks I hook the ground up to the battery and wiggle the shifter and - BAM - I cant unhook the battery FAST enough.
(Ive got my girlfriend standing by with a fire extinguisher by the way)Anybody have any ideas?? (68 Superbee 383/727) And I have very limited experience with electrical.

- - - Updated - - -

I also wondered...I have no ground strap to the body on this car (just battery to Block, and this is brand new)... would this cause it?
Sparks seem to be coming from the entire shifter linkage...

 

[66chargerpat]

You need to have at less one ground strap. I run 1 from batt. to rad. support and 1 from the motor to the firewall.

 

[sleepar]

You need a ground from the engine to the body and at least 8 ga from the head to the fire wall. I would Also run a ground from the opposite side of the firewall ground to some place on the rear of the car like where the tail lights ground to.. so that the ground doesn't rely on the sheet metal alone. Use a brass bolt and nut and lock washer on all the grounds

 

[Vonzy797]

Thanks! Im gonna run to oreillys grab one and see if it still does it...

 

[AMX364]

Battery is grounding thru shifter cables or rods. It can also ground thru the parking brake cables----ask me how I know. More and better grounds to unpainted locations.

 

[Vonzy797]

Battery is grounding thru shifter cables or rods. It can also ground thru the parking brake cables----ask me how I know. More and better grounds to unpainted locations.

Hahaha. I knew there was going to be at least one "ask me how I know".
I put a heavy 4ga ground to the body (to a fender bolt) and then I put a smaller one (an actual ground strap) from the back of the block directly to the firewall. This got me excited... I went to hook the ground up to the battery and now it tried to slightly "weld" it self to the battery terminal (negative side). I stopped and didn't put it on...
The much needed grounds seemed to have amplified the "short" im having... as in - before I has this problem - I could disconnect and connect my battery ground and it wouldn't spark or arc at all. after this shifter linkage fire issue - it would spark slightly - and now after I put the grounds on - it "welds" itself. I wonder if my ammeter in my dash is grounding my leads to the dash/firewall? It seems those two big wires that go to it are the only two that could give me this much of a lightning show. Tomorrow Im going to try and just connect them together with a small bolt and electrical tape to bypass the ammeter completely. Prolly have to take the dash out for that...what a m' f'r.

 

[nm9stheham]

Whoa.....while you are troubleshooting this bad short, I would do the following:

Put a blade fuse inline with all the interior and running electrical system. Disconnect the dark blue wire from the large terminal on the starter relay and put the inline fuse holder inline with this wire. This will fuse the whole system.

Then discconnect everything you can before reconnecting the battery and see if it still blows. Then start reconnecting every electrical system one at a time 'til the inline fuse blows to isolate the problem.

Once all is fixed, take the inline fuse out! It will not be reliable over the long term; this is just to protect your car for now.

 

[Vonzy797]

Whoa.....while you are troubleshooting this bad short, I would do the following:

Put a blade fuse inline with all the interior and running electrical system. Disconnect the dark blue wire from the large terminal on the starter relay and put the inline fuse holder inline with this wire. This will fuse the whole system.

Then discconnect everything you can before reconnecting the battery and see if it still blows. Then start reconnecting every electrical system one at a time 'til the inline fuse blows to isolate the problem.

Once all is fixed, take the inline fuse out! It will not be reliable over the long term; this is just to protect your car for now.

Ill do this. What size fuse would you recommend I put in line?

 

[bm02tj]

The lowest amount you can by wire size and or load

 

[Vonzy797]

I think my ammeter is trash...



I drew a picture to help me explain what I found...
I like to put my handheld volt meter to 'beep' to check for grounding all the time. So... I put the black lead to a bolt on the dash. Then the red lead to "A" NO BEEP. "B" it beeps. "C" it beeps. "D" it beeps.
When I put the dash back in before the lightning show - I hooked A to B and C to D. Then the sparks flew... So I figured it was the ammeter... so I put A and D on the B post and still had the same issue. I don't think the ammeter posts are supposed to be grounded out like they are...
If I connect A to D will that solve my problem??
I was kinda thinking the D wire should not go to ground either... I read about bypassing the bulkhead and just running my alternator hot wire to my starter relay... which I believe that is what the A wire is correct? where does the D wire go to?

 

[Photon440]

None of those connections are allowed to go to ground. There should be a fiber washer under the posts to prevent that.

You can connect A to D, but if you're going to do that you may as well do it under the hood and get rid of the wires going into the firewall to the dash. Some people install a volt meter instead.

-=PHoton440=-

 

[vin_vl29u]

Everyone doing electrical should make a safety jumper like stated above, couple feet of wire, fuse holder (15amps will run everything but the starter), 2 alligator clamps. Clamp from ground post on the batter to the ground cable itself. Any shorts will blow the fuse. If you're having gauge issues, use the smallest fuse you can find 5amps max

Your ammeter should not be grounded on either post. You can connect the two wires together (A and D) to test, use a small clamp or bolt them together, as long as they don't ground out. Make sure A or D are not getting grounded from alternator to gauge to battery.

What I don't understand is moving the shifter causes all the problems. There shouldn't be anything down there with heavy enuff wire to cause the battery cable to "weld on" to the battery post. Unless the battery is in the trunk and you have a battery cable running near the shifter.

That kind of juice I would think it's the positive battery cable or starter shorting out, or something in the charging system alternator to ammeter to battery...

 

[furyus]

Asking the obvious, but do you have the battery hooked up correctly? Did you forget isolators on the amp gauge? Try just hooking the wires to the amp meter to each other only. Can use a bolt to hold the wires together. This will tell you if it's the amp meter. Tape up the wire connection so it doesn't short.

 

[nm9stheham]

In your tests, do you have wires A and D disconnected from ammeter posts B & C. If so, then yes, the ammeter is shorted to ground somehow. If you left D connected to C, then B, C, and D will all be essentially connected together; the ammeter's internal resistance is only a fraction of an ohm.

With the inline safety fuse, you can use anything from 15 to 30 A; your short appears to be so severe that it will take out a 30A fuse immediately.

Can't answer you on where wire D goes to without more info like wire color...you need a schematic. Go here: http://www.mymopar.com/index.php?pid=27

The D wire could have fairly low resistance if several circuits (like dome lights) were turned on when you did the test. Using the ohmeter in 'beep' mode' is OK for seeing if there is a 'low' resistance but it cannot tell you if it is a short or just a low but normal load resistance. You may need to use your meter at times in the lowest ohms scale. (You need to first short your ohmeter's leads together and read their resistance alone, and then subtract that from all other low ohmage readings.)

 

[Vonzy797]

Thank you all for the help - I am fairly confident this is my ammeter shorting out (both terminals are grounding out, the one stud is really sloppy and so are the guts of the gauge). I printed out my wiring diagram got out some highlighters and found exactly what I was looking for. Im going to do the MAD upgrade.
http://www.madelectrical.com/electricaltech/amp-gauges2.shtml
Hopefully this gets the old girl going again!