Electric Load

[my73charger]

I need some help with my electrical system.  This has been an ongoing issue.  As some of you are aware, I recently has some issues that included some of my wiring melting down.  I repaired everything, put it back together and also added the parallel wires to the ampmeter that Nacho recommends.  The issue is this, when I start and run the car it works fine, but as soon as I turn the electric fan on, the ampmeter spikes high when I am running higher rpm's.  It has done this for as long as I have had an electric fan.  The fan is a large single 16" - 3600 cfm fan.  I have the fan wired in with a relay and circuit breaker according to the following (I have a manual switch so I used the bottom diagram): http://www.automotiverewire.com/Documents/ElectricFans_Simple.pdf

What possible issues can cause the high charge when the fan is on?  Couple more things, I have a stock 60 amp alternator and stock voltage regulator and I also run an electric fuel pump.  Thanks in advance for any ideas!

[Cooter]

When running an electric fan, the "Spike" is normal. Those things pull like between 30-60 Amps. ALOT of current draw.

[W4ATL]

When running an electric fan, the "Spike" is normal. Those things pull like between 30-60 Amps. ALOT of current draw.

Agreed...look up the current draw for the fan you have and I bet it takes a lot of current to keep it running. So the alternator is supplying the current to the fan - which is good. Now the alternator is supplying current to charge the battery and to power the fan so you should see extra charge on your meter.

It is not surprising to see the initial spike of current when the fan cuts on. Electric motors need a lot of current to start up. Once started the current reduces. This initial startup current doesn't last long but it does happen and the wiring needs to be able to handle this brief surge of current.

[my73charger]

Ok, the fan I have is suppose to settle down and draw about 15 amps after the initial startup of 30-40 amps.  The meter spikes up and just stays there when I turn the fan on.

[W4ATL]

OK...the meter is most likely not reacting fast enough to the startup current so you aren't seeing that. I don't think you have any issues here. The alternator is providing the extra current to power the fan and that is showing up on the ammeter.

[Cooter]

Ok, the fan I have is suppose to settle down and draw about 15 amps after the initial startup of 30-40 amps.  

Yeah, That's what they claim....

Especially if your running the stock Chrysler Alternator that maxes out at like 60 AMPS.. That's like almost 1/4 of your total output. Not to mantion, the fan might be Magnifying another problem in the wiring. I would NOT look to the stock gauges to be accurate.

[my73charger]

I was thinking about upgrading to an 80 amp alternator.  I recently bought a new gauge set that includes a voltmeter, which I have not hooked up yet, but I planned to hook up and just run as well as the stock ammeter in the dash.  Is there any reason I couldn't just bypass the ammeter all together?  My only fear is that the old ammeter will heat up and start some trouble.

[Dino]

Is there any reason I couldn't just bypass the ammeter all together? 

None, go for it.

[my73charger]

Now how do I do it?

[W4ATL]

Its as easy as running a heavy gauge wire (like 10 gauge) from the alternator to the battery terminal on the starter relay. Use a fusible link at the starter relay battery connection.

Nacho promotes running an extra wire to the ammeter in order to bypass the poor bulkhead connectors if you want to keep the ammeter.  Study this thread.

http://www.dodgecharger.com/forum/index.php/topic,33574.0.html

Instead of running to the ammeter just hook the new wire from battery to alternator. Install the voltmeter so you know what the condition of the charging system is.

[my73charger]

Ok well I did run a 10 gauge parallel wire to the ammeter and then up to the starter relay with a new fusible link, but now I am wondering if I should have just bypassed the ammeter altogether.  Maybe I am good to go now.   

[W4ATL]

I think you are good the way you have it. If you studied the diagrams from the previous link you can see that the load for the lights and other accessories is BEFORE the ammeter so any current that is drawn from the lights or other accessories is not shown through the ammeter. I bet you have your fan hooked to the battery so current to the fan is going through the ammeter and that is why you see it as an extra 'charge'. If all you have is the battery on the other side of the ammeter then the ammeter will only show the charge of the battery.

[my73charger]

Sounds good.  Thanks!   

[Chryco Psycho]

Most of the load will now bypass the ammeter through the jumper so you should be fine , I would clean the bulkhead plugs & coat them with di-electric grease &make sure the ammeter connections are tight

[my73charger]

Hi Chryco,

I did clean the ends and coat them in di-electric grease.  I ran the wires back up to the ammeter though, so I am assuming your statement about bypassing the meter does not work for the way I did it.  I was thinking about splicing the two wires together before they go through the firewall to cut the ammeter out of the picture entirely though.  Any thoughts on this?

[Chryco Psycho]

could be done that way or just bolt both wires to one post on the back of the gauge .
with the jumper in place there would be light load across the ammeter & bulkhead plugs even if you leave it as is .

[my73charger]

Ok thanks!