Have you had your battery checked? Has this set up worked for a while or has this been a issue sense changing over to the 3G? As Steve said check your battery voltage before you start the car then again after its running, voltage shoud go up when car is running. Where did you connect your Amp meter? It does not connect to the sme wire as the Alt light would, green/red. (sorry had to ask) Green/red should be hot when key is in the run position. Yellow wire should be connected to the batter or near it to monitor battery foltage. If you used a MEGA fuse did you check to see if if is good. Just some things to check.

You can test your alternator by setting your multimeter to 20V or more, and connecting the leads accross the battery when running and not running.  Voltage should be in the 13-14 range when running.

As an aside, 65 non GT cars had the sweep speedo cluster with lights.  65 GT cars have a cluster that appears the same as the 66 cluster from the front, but a close examination of the back of the cluster reveals a different ammeter.  65 GT and 66 clusters are different, and the wiring for the ammeters for 65 GT and standard 66 clusters are different.  If a 66 cluster has been dropped in without rewiring, the gauges will not read correctly.  See JamesW's website for the tips to put a 66 cluster in a 65.

My car is a 65 with the Pony interior option.  I thought that the 5 guage cluster was part of this option package?  I used new wiring up to the solenoid (which I replaced) and disconnected the voltage regulator and tapped into the "I" terminal wire near the battery.  I did not remove any stock wiring between the solenoid and voltage regulator. I have all new battery cables.  I will get my battery load tested this weekend.  Thanks!

wemjr wrote:

Thanks for the quick feedback and suggestions!  I have it wired just like this diagram:





I am using the factory guage and connection.  I have been having issues since i did the conversion.  Maybe my battery is bad. I will do the checks you suggested later this afternoon.

    Did mine just like your diagram. 

 

Okay guys.  Here goes....I went home and put my charger on the battery for about 2 hours.  I checked the voltage and it read 12.6.  When I rev'd the engine it would go only as high as 12.8 to 12.9.  I let it run long enough for the electric cooling fan to turn on and the voltage dropped to 11.2 and held steady.  I rev'd the engine and it barely got above 11.7.  I forgot to check the cranking voltage.  I will do that tomorrow.  That being said, any ideas now?  Is my alternator bad?  Or do I just have a toasted battery?  The cold cranking amps are 525.  Thanks!

Have you verified that you really have voltage at the lt.grn/red wire?  I think some of the connections in that circuit may go through the firewall and if you have a bad connection at that junction you may not be getting your 12 volt source. Sounds like the battery is fine - it just isn't charging.  Put it on the charger again and jumper the grn/red wire to the battery to see if it starts to charge or just measure voltage where it connects into your old wiring to verify that you have 12 volts.  Any chance you blew the fuse at some point?  Even with the lights on and fan on, with 130 amps you should be running at 14 volts when you come off idle.  What size alternator pulley and crank pulley are you running?

NO NO NO, GP wants you to jumper the lt green/ red to positive. Always best to used a fused jumper if you have or can make one.

Just out of curiosity, where exactly did you connect the gr/red wire?

Last edited by wsinsle (5/09/2015 5:52 AM)

Hey guys!! I jumpered the lt grn/red wire to the positive side of the solenoid and the volts jumped up to 14.77!  I had originally connected it to the "i" terminal on the old voltage regulator wiring.  Now it seems to be working great.  I let the electric fan come on and turned on all of the lights and volts dropped to 13.45 and when I rev'd the engine they went back to a steady 14.77.  The fan even seems to run faster.  Now my only problem is the alternator belt is squealing like a banshee.  Any idea as to why jumping the lt grn/red wire directly to positive made a difference?  Thanks for everyone's input.  You all ROCK!

Just don't leave the wire jumped to steady positive. This would probably drain the battery when not running, and maybe damage the Alt. You need a wire that is hot when the car is running only to connect to the gr/red.