amp gauge question for mopar gurus

[Kaegi]

My amp gauge does not work in the D300. it does not read low when loads are put on the system or igher when charging like it should. Is it true with mopars that when the amp gauge fails the system will not charge? i.e. not let the the charge thru to the batttery?

[junior]

Start the engine and after a few minutes,remove the neg. battery cable.If the engine stops,it is not charging,but it would be the alternator,not the gage. Your gauge is probably defective or the connections are loose or corroded. One side + I think goes to battery at your starter relay switch.The - side goes to the alternator. Disconnect the battery and clean ALL the connections with sand paper or a small wire brush. If the amp gauge works,that was your problem.If not,you may need another gauge. Removing the fuses from the fuse box and spraying the terminals with WD-40 and scrapping them clean with a small screw driver can be another option.

[chilort]

It may have been bypassed at some point. The amp gauge can't handle all that much of a load. And the wiring to it is on the small side. I don't know how long you've had the truck but it could be that a previous owner simply bypassed the gauge (possibly installed bigger wire too) in order to eliminate a known failure point especially if they added a number of electric parts. Just one of the many possibilities.

[Kaegi]

NOpe I installed the gauge panel and all wires are in great original condition. that is why i think its the gauge. 61s do not even have a fuse box like the later trucks so fuse is out. Unless it has an inline fuse I am not aware of. back to manual diagram! if the gauge worked and the alternator or regulator did not the gauge should show discharge. that is what makes me think gauge is bad.

[Russ]

I'm not a big fan of pulling a battery cable while the engine is running. The battery is the load for the alternator. If you unhook it the alternator output can possibly "spike" and damage something. Definitely never do it on late model computerized cars. I suggest tht you check the alternator buy using a voltmeter and checking the voltage at the battery when the truck is running just after starting it up. The voltage should be about 12.5 to about 14 volts if the charging system is working properly. It's also quicker and easier than unhooking a cable.

[Kaegi]

already did the cable trick it is not charging. so back to original question if gauge is bad will it stop charging? I think so but not sure on this design.

[712edf]

Correct. If the ammeter has an open circuit the alternator won't properly charge the battery. To test place both wires onto the same post of the gauge, then start the vehicle & do the cable removal test. If it keeps running you have found your problem. If it still dies then the charging problem is elsewhere, but gauge may still not be functional.

Bucky

[Kaegi]

Being the super genius that i am I went to the truck opened the hood and had it fixed to less than one minute! it helps if the dang fan belt is tight! DOH! the nut onthe anchor bolt for the alt was missing and the anchor bolt on the adjustment bar was loose. so between the 2 the belt totally slacked off.

[MountainMoparRobin]

I'm not a big fan of pulling a battery cable while the engine is running. The battery is the load for the alternator. If you unhook it the alternator output can possibly "spike" and damage something. Definitely never do it on late model computerized cars. I suggest tht you check the alternator buy using a voltmeter and checking the voltage at the battery when the truck is running just after starting it up. The voltage should be about 12.5 to about 14 volts if the charging system is working properly. It's also quicker and easier than unhooking a cable.

if your altenator & regulator is working properly their is no spike's, the regulator will only send whats needed to the system, thats the good part of pre 1980 vehicles you can drive them without a battery, for once its started the altenator provides all current for the vehicle to run and it only give a surface charge back to the battery to replinish what was used, the voltage needed to fire the plugs and play your radio, headlights and etc. are the load, the battery should be finished recharging within the 1st 3 minutes, thats why your needle will be straight up on your guage or slighly to the charge side. I just drove the 65 from Colorado Springs to Lakewood like that, just don't shut it off if its an automatic, standards you can pop the clutch and off you go

[MountainMoparRobin]

Being the super genius that i am I went to the truck opened the hood and had it fixed to less than one minute! it helps if the dang fan belt is tight! DOH! the nut onthe anchor bolt for the alt was missing and the anchor bolt on the adjustment bar was loose. so between the 2 the belt totally slacked off.

at least you found it without more headache

[Jeffc]

Rules for seeing if the alt gauge has failed if wires are stock in any 60's mopar.......
Rule one.....
if you can turn the key on and you can start the engine the amp guage is working
if you can't then ether the gauge has failed or your not getting power to the gauge......

in being around and owning old mopars 60's and 70's for 40 years (granted my own are pretty stock without a
lot of add "stuff") I have never, ever, had a amp guage fail yet...... keep your alt's under
75amps in the stock systems and your pretty safe, go higher with out system upgrades
and add a lot of power eating stuff and you will cook things.....

Keep your wire in good shape, clean all contections- hot and grounds- saves a lot of problems
at are common.....

[Kaegi]

I'm not a big fan of pulling a battery cable while the engine is running. The battery is the load for the alternator. If you unhook it the alternator output can possibly "spike" and damage something. Definitely never do it on late model computerized cars. I suggest tht you check the alternator buy using a voltmeter and checking the voltage at the battery when the truck is running just after starting it up. The voltage should be about 12.5 to about 14 volts if the charging system is working properly. It's also quicker and easier than unhooking a cable.

if your altenator & regulator is working properly their is no spike's, the regulator will only send whats needed to the system, thats the good part of pre 1980 vehicles you can drive them without a battery, for once its started the altenator provides all current for the vehicle to run and it only give a surface charge back to the battery to replinish what was used, the voltage needed to fire the plugs and play your radio, headlights and etc. are the load, the battery should be finished recharging within the 1st 3 minutes, thats why your needle will be straight up on your guage or slighly to the charge side. I just drove the 65 from Colorado Springs to Lakewood like that, just don't shut it off if its an automatic, standards you can pop the clutch and off you go

RE compression starting. you can compression start GM Ford and Mopar automatics up till about 1964. they all had rear pumps. you got be rolling at least 30 to 40 for it to work. I got a wet distributor in my first car, 64 impala. up at Stevens Pass and had to compression start it coming dow the pass a bunch of times till it dried out. works like charm. i have done ti with 63 riviera, and 63 Caddy maybe a few others too.