Smoking dash!

[EMCD]

I took my cudq out that was just finished a driver resto. I got on the gas hard and the dash started to smoke slightly. I felt the gauges and the alt meter seemed warmer than the rest. I felt all th wires I could reach under the dash and none of them were hot or burned. The smoke stopped and I drove it home with no issues. I put in a larger alternator, 70 or 75 amp. The wire harness is original and was in great shape and under the hood all seemed fine. The original alt gauge always ticked when I turned on the lights or turn signals. Now, the gauge reads super high on the charge + side. Is a 70 amp alternator too big? Any thoughts?

[MEK-Dangerfield]

I have a 75AMP alternator in my car, so I don't believe that's your problem.

So my questions...

 How long has it been since this car was last on the road?

 If your amp gauge is reading high, I have to ask how good your battery is?

So you have a higher than stock rated alternator now, but it should only put out the AMPs it's told is needed. If the battery is fully charged, I would focus on the voltage regulator. Does it have a good ground connection?

The Amp gauges do go bad, but I'm hesitating on suggesting that since you just changed alternators.
 

[Chryco Psycho]

I think you have 2 problems ,
1] you may have a battery problem or a voltage reg problem as the 70 amp alt should not be charging above 10-20 amps unless you have a lot of electric fans . fuel pumps , efi computer , electric water pump etc , generally the alt will just maintain a charge in the battery
2] yes 70 amp is too much , the ammeter will take 60 amp max maybe , I usually run a jumper with an inline fuse from the alt across to the starter relay battery terminal to bypass the ammeter & bulkhead plug

[EMCD]

I've driven it twice since the resto has been finished. The resto took 13 months. It was a small amount of smoke but it freaked me out. Good thing I had a fire extinguisher, just in case.

[ShelbyDogg]

If that amp gauge is reading super high, you have a short circuit somewhere. Start disconnecting things here and there till you find out what is pulling a high load. I hope that you don't have a bypassed fusible link up front.

A common point of smoke is the arcing at the male female burning up where it plugs in at the bulkhead connector. Check the big red and big black wires first. If it shorted at the amp meter lugs to ground, you wont see the melted wire till you unwrap the harness.

Be careful with this. Something melted somewhere!

[EMCD]

I have dual electrical fans and a 100w stereo. I upped the alternator because of the dim lights and what seemed to be a weak electrical system. The battery is two years old and has been charged on a trickle charger for the whole resto timeframe.

[ShelbyDogg]

I would put a quick disconnect on the battery terminal. This could save your whole car.  Never disconnect it while the car is running. A fire extinguisher will not put out a fire when a wire is glowing red hot an continuously lighting it back up.

[EMCD]

Cool. I'll go get one today. Given the alt gauge was warmer than all the other gauges and all the wiring harness accessible underneath the dash was cool, does that narrow it down to the gauge ground? I cannot see any burns on any of the wires under the hood. My quests if the I shouldn't try to drive or mov the car until I can narrow it down and fix the short. Will I have to remove all the wire tape? Or, is there a better way to start/simplify?

[ShelbyDogg]

Check the exposed ends of the wires before they go into the taped areas. Look for any signs of slightly melted insulation. Cutting open a new harness is the last thing you want to do. The amp gauge's terminals is not grounded and should not be.
The high reading could have been the battery trying to recover after the short circuit, but something shorted and smoked.
You need to try and find out what it was. It could have been the ammeter like you thought.

Like Chryco said, with a big alternator and stuff drawing lots of current, we always add a big wire directly from the alternator charge stud and the starter relay stud or right to the battery positive post. Use a big fuse inline with this wire too. Do not disconnect the original black alternator wire going to the inside.

This will keep all of the extra amperage from going through the ammeter.

[HP_Cuda]

Since you are running the 70A alternator I would at least add the jumper with a fuse between the relay and the alternator to mitigate current flow through your dash harness as Cryco pointed out.

I would disconnect the amp meter and put both of the connectors on one post and be done with it. It just cannot handle that kind of flow.

[EMCD]

Am I good when the car is off? No worries about anything catching on fire if the motor isn't turning? It's been 3 hours since the smoke and I haven't seen or smelt any since? The smoke appear only after I got the RMPs up after a heavy throttle at a stop light? On the drive home, about 3 miles everything was fine.

[dodj]

Is a 70 amp alternator too big? Any thoughts?

I believe the stock alt was 37 amps
Electrical system was designed around that. 

Am I good when the car is off?

Probably, but no guarantees. I would remove the -ve lead from the battery for now.

[EMCD]

So, I pulled the battery leads.the negative lead that grounds to the block was very loose. The positive side that runs to the starter was vey difficult to get off? I had to pry it off with a long screwdriver. In the process, I must have grounded it out because the engine made a small turn over. Does that make sense? Does that narrow down my my smoking dash?

[EMCD]

Does anyone have a picture of the ammeter bypass? My garage thinks that one of the alternator wires is to small of a gauge, but the didn't say anything about a fusable link or bypass.

[72cudamaan]

Does anyone have a picture of the ammeter bypass? My garage thinks that one of the alternator wires is to small of a gauge, but the didn't say anything about a fusable link or bypass.

       www.madelectrical.com/electricaltech/amp-gauges.shtml                                      This shows everything about the bypass