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alternator up grade and smoking dash

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hondo402000

hondo402000

Darth Vader
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took the 6 out for a drive and smelled burning plastic, got back home quickly and started watching and noticed smoke from under the dash. the wires connected to the amp gauge were hot and the source of the smoke. I installed a 55 amp alternator and some of the direction said to run an additional heavy gauge wire directly from the alt to the battery Pos terminal. I had done that but didnt hook it up. While driving at night with all lights on, radio blasting the amp gauge was basically full scale charging. when I hooked the wire to the pos terminal from the alternator the meter goes back to center and the smoked stopped and now all is well. Moral to the story, if you put a high capacity alternator, better run a 8 gauge wire directly to the battery pos and no have all that current going throught the amp gauge
 
no loose connection, I just revaneered the dash and made sure all connections were tight. I have a new radio, amp, haligen head light, PIAA fog lights, everything is running on relays too. I think just too much current running through the amp gauge
 
hondo402000 said:
I think just too much current running through the amp gauge
Click to expand...

I would bet that this is the problem. Dan Masters discusses this when installing his wiring harness, using a higher amp alternator, and retaining the amp gauge. If you go to page 10 of this .pdf from his instruction manual, he will show you some alternatives to take care of the problem.

I'm going to be faced with the same thing when I install his harness with an alternator in my TR3, and will be installing a shunt that will divert about half of the current so I can retain the original ammeter.
 
So if I decide to switch over to the previously recommended 1978 Fiesta 55 amp alternator, from my 37 amp stock unit, I would have to change the wiring and or the gauge? I though that it was said to be a bolt in change with no issues involved.

I wouldn't think that an 18 amp (at peak) difference would require heavier gauge wiring or a new gauge, but from what the Masters manual states, that would be the case.

I have a spare ammeter. I wonder if I should call Nisonger or Gauge Guys and ask if they can convert it to a 50 amp or higher to correct this problem, then just swap out the gauge if I change the alternator?

Does anyone have any thoughts about that idea?
 
Brosky, I also have a '74 TR-6. I switched to a 75 amp GM alternator. I'm running an electric fan and an electric fuel pump. I left the original wire in. So far no problems. I wonder if the later cars have a heavier wire than the earlier cars? The changeout was very easy on the wiring side. It may be because the later cars have a voltmeter instead of an ammeter. There is some very good information on this changeout on the VTR site.
 
Paul, the Bosch unit doesn't require any changes,the Delco unit,however, recommends wiring upgrades.Notice I say "recommends", but isn't a necessity.
 
Thanks!!

And the wood dash is lookin' very good.....
 
Paul, What are you on the puter for. Should be out enjoying the 4th with your family. Here I have an excuse. It is still early and I am waiting for the family to get ready to leave.
 
/bcforum/images/%%GRAEMLIN_URL%%/iagree.gif As long as the original connections are clean and tight, they will carry the increased current for the short time it takes to recharge the battery. Once the battery is charged, the current through the ammeter & wires is no higher than it was before.

IMO, hondo402000 had a poor connection at the back of the ammeter. Those Lucar connectors are not particularly wonderful, IMO, so eliminating them would be a useful upgrade. But not essential.
 
"eliminating them would be a useful upgrade."

Change them to what?
 
DNK said:
Change them to what?
Click to expand...

I'd have to see the ammeter (my TR3 ammeters don't use Lucar and the Stags don't have ammeters). But one option might be to solder a ring terminal to the wire, and drill the ammeter tab for a bolt.

Or even just replacing the Lucar with the same style terminal from AMP would be an improvement, IMO.
 
paul, the ammeter is a 30 amp max unit and by running additional power thru it you are running the risk of melting the wiring or burning out the gauge. its a much better idea to run the main power to the battery instead of thru the ammeter to the battery. i have seen gauges fail and cars burn from it. the ammeters are becoming more rare these days as opposed to the volt meter.
Randy
 
I have thought about this problem for a long time and wonder if part of the problem is the connection in the middle of the positive battery cable at least on my '76. If that is the case even connecting the original cable directly from the alternator to the battery would seem to be an improvement.
 
Sorry, another brain gas pass on my part.

I have a Voltmeter (as all 74 TR6's do), not an Ammeter.

Thank you all for not pointing it out to me in an unkind manner.
 
Yeah, connecting the alternator output directly to the volt meter could make for an unhappy day...
 
Paul,

when I rewired Crypty I also upgraded to a GM alternator.
An 8 gage wire came with the Dan Masters wire harness
and I had to purchase an upgraded amp meter.

But Dan does show you how to install a shunt to keep your original amp gauge.

d

/bcforum/images/%%GRAEMLIN_URL%%/nonod.gif
 
I checked all three wires to the amp gauge, the 2 main ones I crimped the connectors so they would fit tight, It was the small wire that was heating up, the brown/white going to the starter, it has a round terminal and it bolted to the amp gauge but a spade connector on the starter. It was easier to just add the 8 gauge wire from the alt to the pos terminal on the battery
 
hondo402000 said:
I checked all three wires to the amp gauge, the 2 main ones I crimped the connectors so they would fit tight, It was the small wire that was heating up, the brown/white going to the starter, it has a round terminal and it bolted to the amp gauge but a spade connector on the starter.
Click to expand...
Strange, the brown/white should go to the ignition switch, not the starter. It's the main power feed to the rest of the car, so carries all the current all the time (whether the current comes from the battery or from the alternator).
hondo402000 said:
It was easier to just add the 8 gauge wire from the alt to the pos terminal on the battery
Click to expand...
Which is fine if you don't care that your ammeter is now useless. It will show discharge all the time, whether the alternator is working or not.

And that you haven't done anything about the brown/white getting hot.
 
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