[stephen henshaw]

OK I know we have a bad earth.
everything works except the batt dash light stay and gearbox temp

1 previous owner has placed on passenger side,earth cable to the alternator from the negative
2 batt light on dash is on but flickers some times so it is try to work.
3 we are charging 13'5volts on a digital gauge but it does bounce by half a volt.
where should I start .
steve h

 

[6riders]

Throw up a picture of the alternator wiring you are talking about. Could need a new alternator pigtail

Check and/or replace the battery ground cables on both batteries, block to frame and block to body. Could be time for the "big 3" upgrade.

 

[stephen henshaw]

Throw up a picture of the alternator wiring you are talking about. Could need a new alternator pigtail

Check and/or replace the battery ground cables on both batteries, block to frame and block to body. Could be time for the "big 3" upgrade.

sorry big 3 upgrade what is that.
steve h

 

[6riders]

sorry big 3 upgrade what is that.
steve h

Upgrading the battery cables. I replaced my positive cables with 2/0 from battery to battery and to starter. My grounds wit 1/0 from battery to frame to engine block on both sides. Added a 4 gauge cable from alternator to driver battery.
I used top post to side post conversion clamps. This allows me to disconnect just one battery or both. The stock system does not allow that.
I'm interested in the ground cable, do you have a picture?

 

[TooManyToys]

OK I know we have bad earth.
everything works except the batt dash light stay and gearbox temp

1 previous owner has placed on the passenger side, earth cable to the alternator from the negative
2 batt light on the dash is on but flickers some times so it is trying to work.
3 we are charging 13'5volts on a digital gauge but it does bounce by half a volt.
where should I start?
steve h

You have a bad diode in the alternator which is spilling excessive AC voltage. The dash light is not just a go/no go indicator, it tells if the voltage output is balanced to the batteries. Excessive AC influences that balance, so the light can go on, including flickering at different RPMs, and that can show as digital meter values. However, depending on how you are reading volts, the OBD2 readout reports some system volts in 0.5 increments, so you always see a 0.5v swing.

If you have an automatic transmission, it's not unusual to have the temperature sensor go out, it's not related to the alternator.

 

[stephen henshaw]

You have a bad diode in the alternator which is spilling excessive AC voltage. The dash light is not just a go/no go indicator, it tells if the voltage output is balanced to the batteries. Excessive AC influences that balance, so the light can go on, including flickering at different RPMs, and that can show as digital meter values. However, depending on how you are reading volts, the OBD2 readout reports some system volts in 0.5 increments, so you always see a 0.5v swing.

If you have an automatic transmission, it's not unusual to have the temperature sensor go out, it's not related to the alternator.

the previous owner says he replaced it (temp sender) all I have read so far , no one has reported a broken dash gauge that I have seen, so maybe this is just another lie that he replaced the sender??

 

[stephen henshaw]

the previous owner says he replaced it (temp sender) all I have read so far , no one has reported a broken dash gauge that I have seen, so maybe this is just another lie that he replaced the sender??

the batt light on dash only flickers at low rpm, after 1200rpm it stays on.

 

[TooManyToys]

Bad diode(s); replace alternator.