Main Menu

How much can ammeter handle?

Started by nsmall, September 14, 2017, 08:32:00 PM

Previous topic Next topic

0 Members and 1 Guest are viewing this topic.

nsmall

@Burdar @Shane Kelley

A Mopar friend of mine who's helping me piece my car back together thinks that I'll be just fine to hook up the ammeter gauge.

Well I have an electric fan that draws 19 amps.  My alternator draws 59 amps.  Everything else is stock.

Redline gauges who restored my gauges thinks it's in my best interest to NOT hook up the ammeter gauge and just put a bolt through it and wrap it up to bypass it.  I didn't do the volt conversion as I am out of money like 20 grand ago.

The guage was tested and works fine. 

I know I've already asked you guys about this whole situation before I'm just trying to make the best decision.

So am I really risking trouble here?

I've read about how you can hook a gauge to the cigarette lighter but I don't know if my cigarette lighter is works. 

Thanks in advance.

Chryco Psycho

Your ammeter will handle 60 amps +or -, I doubt you would have a problem at 65 which is no issue as the max you Alt will put out is 60 so in that respect you are fine .
if you bypass the gauge you need to just connect both wires to only 1 terminal & make sure it is tight
As a std practice I do bypass the ammeter & use a bypass to take the alt output directly to the battery at the start relay as this is far safer than going through the firewall , ign switch & ammeter & back through the firewall

YellowThumper

Absolutely confirm your firewall plugs are near perfect. That is where many meltdowns also occur. If it has fatigued it will only steadily get worse.

Bypass doesn't cost hardly anything. Add a low cost volt meter or convert amp to volt. There are writeups on low cost options for that.

Electrical is not place to draw $$$ line.
Life is to be viewed thru the windshield. Not rear view mirror.
You are the only one in charge of your destiny.

Mike.


Burdar

Your AMP gauge is going to be useless with the bypass wire from the alt to the starter relay.  In order for the gauge to read accurately, all the power from the car has to run through it.  If most of the juice is being bypassed, what's the point in having it?


CudaMoparRay


Chryco Psycho

I will slightly deflect with the load , but overall I agree Volt meter is safer

Skunkworks Challenger

I did the amp meter bypass and ran the altnator feed directly to the starter solenoid as Neil suggested.  I also installed relays for the headlights. In addition I replaced all the connectors in the firewall passthrough.  Now my headlights don't dim at stop lights and I don't worry about melted wires.  Since I don't smoke I placed a volt meter in my ash tray and at shows I close the tray.


dodj

Quote from: nsmall on September 14, 2017, 08:32:00 PM
@Burdar @Shane Kelley
Well I have an electric fan that draws 19 amps.  My alternator draws 59 amps.  Everything else is stock.
Seeing as  $ are really tight;
1/ Run a #8 wire from alt o/p/ to +ve battery terminal.  cost < $5
2/ Use a relay for that fan. Relay cost about $5-$10.
3/ When able, spend $25 on a voltmeter. They are cheap and easy to wire in.
:cheers:

"There is nothing your government can give you that it hasn't already taken from you in the first place" -Winston Churchill

nsmall

@dodj

I already have a fan relay with its own fuse that runs from the fan to the starter relay.  So would that mean that I'm NOT running 19 amps to the amp gauge?

@Burdar   Darren at this point I don't have the bypass wire running from the alternator to the starter relay. I'm just trying to balance Redline gauges saying don't do it and then a guy who's helping me saying let's hook up the amp gauge.

I'm just starting to think it's just best Not to hook up the amp gauge as if it's potentially dangerous why would I risk it.

So if run that bypass wire from the alternator to starter relay and join my amp meter wires....that's it?  Bypass done?

Does the alt to starter wire need a fuse? 

Thanks a lot.

Neil

RUNCHARGER

I would certainly use protection on a wire from the alternator.
Sheldon

73440

I think It could use a fusible link , slightly smaller than the guage wire you are going to use.


Burdar

You had already said that you were going to run a bypass wire. With that wire hooked up, the AMP gauge is rendered useless. The only way it works is if all the power from the car runs through it. Since you are going to install the bypass wire, don't hook up the AMP gauge?

Some people don't think a fuse or link is needed on the bypass wire since it's a really short run. The chances of it shorting to ground are slim. They might be right but what's the harm? I'd run a fuse able link on both ends.

Regarding the AMP gauge...When the gauge doesn't have power, where does the needle point? Does it just stay in the middle or does it swing to one side? Just for looks, you might want to rig it up to stay in the middle all the time.

Skunkworks Challenger



Regarding the AMP gauge...When the gauge doesn't have power, where does the needle point? Does it just stay in the middle or does it swing to one side? Just for looks, you might want to rig it up to stay in the middle all the time.
[/quote]

It would stay in the middle all the time.

dodj

Quote from: Skunkworks Challenger on September 16, 2017, 12:04:31 PM


Regarding the AMP gauge...When the gauge doesn't have power, where does the needle point? Does it just stay in the middle or does it swing to one side? Just for looks, you might want to rig it up to stay in the middle all the time.

It stays in the middle.

Does the alt to starter wire need a fuse? 

Yes it should. It can be very large though cuz you're really only guarding against a short to ground. I use an 80 amp MANL fuse on the bypass wire. A fusible link protects the 'in car' circuitry.

The fan relay keeps the fan's high current draw off the bulkhead connector, so that's good.
"There is nothing your government can give you that it hasn't already taken from you in the first place" -Winston Churchill

Burdar

The problem with 1 fuse on the bypass wire is that it is being fed from both ends.(alt end and relay end)  If the fuse blows, the wire still has power being fed to it from the other end.  That's why I'd use two links or two fuses. 1 right after the alt and one right after the relay.  If the bypass shorts to ground, BOTH fuses will blow and the wire will be totally dead.