1G 1G DSM OVERVOLTAGE!!

[Anthony Boni]

Man I swear I have nothing but electrical issues with this car and I SUCK at electrical stuff. In both link and from my multimeter, I’m showing 15.2-15.4 volts. My tuner told me to replace my alternator, so I did. Still the same reading. Had both alternators tested at auto zone, they both passed. Both are OEM Mitsu 75 amp alternators. I have 0 ohms of resistance from my alternator to chassis. What else can I check? @steve i know you’re an electrical guru and I need all the help I can get if you don’t mind giving me some pointers. Thanks in advance guys!

 

[llxkevinxll]

Man I swear I have nothing but electrical issues with this car and I SUCK at electrical stuff. In both link and from my multimeter, I’m showing 15.2-15.4 volts. My tuner told me to replace my alternator, so I did. Still the same reading. Had both alternators tested at auto zone, they both passed. Both are OEM Mitsu 75 amp alternators. I have 0 ohms of resistance from my alternator to chassis. What else can I check? @steve i know you’re an electrical guru and I need all the help I can get if you don’t mind giving me some pointers. Thanks in advance guys!

Check the connection for the two smaller alternator wires. These provide the alternator with feedback for voltage regulation. If the connector or wiring is bad it would explain why two working alternators are generating too large of a voltage.

 

[Anthony Boni]

Check the connection for the two smaller alternator wires. These provide the alternator with feedback for voltage regulation. If the connector or wiring is bad it would explain why two working alternators are generating too large of a voltage.

How do I check them? I saw the wiring diagram for the alternator and it’s like looking at a trigonometry problem to me. Do I check for continuity? Resistance? Voltage?

 

[llxkevinxll]

https://www.dsmtuners.com/threads/2-minute-alternator-circuit-test.226323/

Walk through that. Should point you in the right direction.

 

[Anthony Boni]

https://www.dsmtuners.com/threads/2-minute-alternator-circuit-test.226323/

Walk through that. Should point you in the right direction.

Awesome thanks man! I don’t have a test light, but I have a multimeter. So I’m just testing for continuity, if I’m reading this correctly?

 

[llxkevinxll]

Multimeter is fine. Use the voltage setting. Reading battery voltage on the meter can be replaced in that guide for a lit test light.

 

[Anthony Boni]

Multimeter is fine. Use the voltage setting. Reading battery voltage on the meter can be replaced in that guide for a lit test light.

Alright just a moment I’ll go knock this out real quick!

 

[Anthony Boni]

Multimeter is fine. Use the voltage setting. Reading battery voltage on the meter can be replaced in that guide for a lit test light.

Oops didn’t mean to post that. Here’s a picture I snapped. The large white/yellow looking wire is disconnected completely. There’s another small white yellow that has been cut. I think that is for the power steering connector to let the ECU know when you are turning the wheel so the motor will increase in RPM. And I have a black/white striped wire going into the connector.

Multimeter is fine. Use the voltage setting. Reading battery voltage on the meter can be replaced in that guide for a lit test light.

 

[llxkevinxll]

Right. I'd expect you'll see a voltage between ground and battery. A dimly lit test light would be a weak voltage as the resistance of the test light is fixed and current is consumed by the light based on V=IR (Ohm's law). Only remaining variable is voltage to determine brightness. You should see a voltage in step 3, and then a larger voltage in step 4.

 

[llxkevinxll]

Oops didn’t mean to post that. Here’s a picture I snapped. The large white/yellow looking wire is disconnected completely. There’s another small white yellow that has been cut. I think that is for the power steering connector to let the ECU know when you are turning the wheel so the motor will increase in RPM. And I have a black/white striped wire going into the connector.

That'll be the issue. The alternator has no voltage feedback to adjust itself. Thus your higher than desired voltage. You can crimp some spade connectors on to get it attached enough to make the charging system function properly. Ideally, I'd go to Sheridan Engineering and get a replacement connector and terminals and get it all patched back up to factory original.

 

[Anthony Boni]

That'll be the issue. The alternator has no voltage feedback to adjust itself. Thus your higher than desired voltage. You can crimp some spade connectors on to get it attached enough to make the charging system function properly. Ideally, I'd go to Sheridan Engineering and get a replacement connector and terminals and get it all patched back up to factory original.

Patched her up! She’s steady at 14.4 volts. Thanks so much!!!!!!

 

[llxkevinxll]

Patched her up! She’s steady at 14.4 volts. Thanks so much!!!!!!

Perfect! Glad you got it working.

 

[steve]

Great job guys.
Whatever is leaking all that oil isn't helping things.

 

[Anthony Boni]

Great job guys.
Whatever is leaking all that oil isn't helping things.

Yessir that’s just power steering fluid from when I removed the pump to get my old alternator out. I’ll clean it up, was just in a hurry

 

[pauleyman]

Next time don't disconnect the pump. Just unbolt it and move it out of the way and leave the lines connected and you won't make a mess

 

[pauleyman]

It really hurts me but I have to say next time is
As there always seems to be a next time

 

[Anthony Boni]

Next time don't disconnect the pump. Just unbolt it and move it out of the way and leave the lines connected and you won't make a mess

Hopefully there won’t have to be a next time!! Thanks for the advice, I’ll be sure to remember that if/when I need to replace my alternator... again

 

[Doc Rey]

Check the connection for the two smaller alternator wires. These provide the alternator with feedback for voltage regulation. If the connector or wiring is bad it would explain why two working alternators are generating too large of a voltage.

Hi, I think think the voltage regulator must also be checked. There’s some sort of contact point in there that must be automatically release by itself whene there’s surge of over changing.

 

[curt-s]

It really hurts me but I have to say next time is
As there always seems to be a next time

wait..
that's not supposed to be there? I have always thought that is the anti-rust coating my car liberally reapplies on it's own..
maybe I should replace my PS seals (again)

 

[Anthony Boni]

wait..
that's not supposed to be there? I have always thought that is the anti-rust coating my car liberally reapplies on it's own..
maybe I should replace my PS seals (again)

I went to autozone and picked up a variety of O-rings. Think I used a 10mm and 12mm with a crush washer below the jamnut. Hasn’t leaked one bit and cost me $3.00