The Top DSM Community on the Web

For 1990-1999 Mitsubishi Eclipse, Eagle Talon, Plymouth Laser, and Galant VR-4 Owners. Log in to remove most ads.

Please Support STM Tuned
Please Support Morrison Fabrication

New alternator not charging at all

This site may earn a commission from merchant
affiliate links, including eBay, Amazon, and others.

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

paintball4fun21

15+ Year Contributor
169
0
Jun 13, 2006
onalaska, Wisconsin
I have tried 3 brand new alternators and my car is not charging at all. Im measuring it from the alternator positive terminal (and also from the battery). As soon as I turn on the car the voltage starts to drop from 12V. Everything is hooked up right and the belt is not slipping.
I have tried~
-Re wiring it
-checking the alternator fuse
-adding grounds
-it has a new battery
no luck
Im thinking it has to be one of the wires from the alternator pigtail connection, since the alternator is good but is not putting out anything at all. How can I go about following these wires or checking for a short in them or something?
 
If your worried about the wires not having good contact, measure voltage directly at the terminal on the alternator and at the battery. The difference should not be more than .5V. If it is, you have a bad connection causing high resistance.

Also, if you don't have 14.5V at the alternator, the voltage regulator is to blame.

Remember if the car runs but always needs a boost, it's typically the battery. If the car starts but will not continue to run, its typically the alternator.
 
Charged up the battery today fully again. It reads 12.75 volts when turned off. When turned on it reads 12.34 volts at the battery and alternator. Again this is my 3rd brand new alternator being tried(so im sure the alternator is good), and the fuse is not blown. I have no idea what this could be! Could the pigtail harness connector, that plugs into the alternator, actually make it not charge? as I said no fuses seem to be blown
 
Last edited:
I'm back in the same boat too. I noticed it randomly will start chargin while driving but not at idle or anything
 
To update you, last night I yanked my whole wiring harness. Found no shorts in the 4 plug connector, the wiring from the alt. positive terminal to fuse box to battery checked out good, 'charging/battery' light checked out good, relay works. I replaced all my ground wires with 4g wire. Block to body, body to battery, battery to block.

Even after all this the alternator still would not work. I guess sitting for half a year killed it. It is an OEM alternator that showed no 'dim dash lights' it simply just wouldn't put out voltage.

I had a spare 'duralast' alternator sitting around that I popped in there. Dash lights were dim, battery/brake/coolant - but the odd thing is, if i reved to 3.5k rpm 1 time, the alternator would kick on and stay on till I shut the car off. WTF is with these cars.
 
yea im still trying to deal with this problem. I know the alternator is good and the battery, and the power wire going to the fuse box. also all the fuses look good. I have no idea why my alternator is not charging the car. this is terrible, cant figure it out

To update you, last night I yanked my whole wiring harness. Found no shorts in the 4 plug connector, the wiring from the alt. positive terminal to fuse box to battery checked out good, 'charging/battery' light checked out good, relay works. I replaced all my ground wires with 4g wire. Block to body, body to battery, battery to block.

Even after all this the alternator still would not work. I guess sitting for half a year killed it. It is an OEM alternator that showed no 'dim dash lights' it simply just wouldn't put out voltage.

I had a spare 'duralast' alternator sitting around that I popped in there. Dash lights were dim, battery/brake/coolant - but the odd thing is, if i reved to 3.5k rpm 1 time, the alternator would kick on and stay on till I shut the car off. WTF is with these cars.

I fixed my issue tonight! It was the alternator relay under the air intake/coolant overflow. The relay had a wire broken off and it was corroded. I ended up cutting the wires and put spade connectors on them to connect to the relay(after i wire brushed the corrosion off). works great charging at 14.5 volts at idle now!
 
Support Vendors who Support the DSM Community
Boosted Fabrication ECM Tuning ExtremePSI Fuel Injector Clinic Innovation Products Jacks Transmissions JNZ Tuning Kiggly Racing Morrison Fabrications MyMitsubishiStore.com RixRacing RockAuto RTM Racing STM Tuned

Latest posts

Build Thread Updates

Vendor Updates

Latest Classifieds

Back
Top