2002 s40 1.9t Battery Ground Terminal Hot

[diggerdude]

For some reason my Battery Ground connection gets very hot when I run my head lights. I have cleaned battery terminals, checked ground connections to body and where the ground bolts to transmission and it all looks good. Battery cables look in new condition. Checked resistance between positive post and alternator and it reads 0.10v Also do not know if its normal, but the top of the radio gets very hot also. I found that because I had the Climate control out of the car and just happened to touch the top of the radio housing to move it over.

I would appreciate some feed back!
Thanks!

[Clan]

Originally Posted by diggerdude

For some reason my Battery Ground connection gets very hot when I run my head lights. I have cleaned battery terminals, checked ground connections to body and where the ground bolts to transmission and it all looks good. Battery cables look in new condition. Checked resistance between positive post and alternator and it reads 0.10v Also do not know if its normal, but the top of the radio gets very hot also. I found that because I had the Climate control out of the car and just happened to touch the top of the radio housing to move it over.

I would appreciate some feed back!
Thanks!

Normal for the radio to get hot ! Try the voltmeter check between the centre of the lead battery post and chassis , with your loads on .. should be about 0.2 Ohms ... heat = resistance , it could be a poor crimp connection at the battery earth clamp . If all is well then the heat would be coming from the inside of the battery , not good !

[gatos]

Is there any corrosion on the crimp that bolts on the chassis?

[diggerdude]

Originally Posted by Clan

Normal for the radio to get hot ! Try the voltmeter check between the centre of the lead battery post and chassis , with your loads on .. should be about 0.2 Ohms ... heat = resistance , it could be a poor crimp connection at the battery earth clamp . If all is well then the heat would be coming from the inside of the battery , not good !

Thank's for the advice! I will check this out. The cable crimps look good, all clean and tight connections. Could it be in the alternator at all?

[clarkey1984]

The heat will only be present at the site of the high resistance, so its either the cable where it goes into the connector, the connector, or the battery post itself, it cant be anything else, if it were either the cable lower down or the other end of the cable where it bolts to the body then that's where the heat would be, if it were me id change the cable and connector at the same time just to be safe.

[diggerdude]

Originally Posted by gatos

Is there any corrosion on the crimp that bolts on the chassis?

No corrosion anywhere, everything looks clean ad in new condition. Maybe I should change the battery ground cable and see what happens.

[diggerdude]

Originally Posted by clarkey1984

The heat will only be present at the site of the high resistance, so its either the cable where it goes into the connector, the connector, or the battery post itself, it cant be anything else, if it were either the cable lower down or the other end of the cable where it bolts to the body then that's where the heat would be, if it were me id change the cable and connector at the same time just to be safe.

Thank You!

[diggerdude]

Originally Posted by clarkey1984

The heat will only be present at the site of the high resistance, so its either the cable where it goes into the connector, the connector, or the battery post itself, it cant be anything else, if it were either the cable lower down or the other end of the cable where it bolts to the body then that's where the heat would be, if it were me id change the cable and connector at the same time just to be safe.

I've decided to replace both battery cables, I cut away both upper wire coating's on the positive cable and inside that new looking cable was full of corrosion. Can you tell me what all I need to remove to change the positive cable? (New to Volvo) 2002 s40 1.9t. Project car I took on for my 16 year old Son.

[skyship007]

Copper is a real good conductor of heat, so if one end gets hot, it's possible for the cause to be that the cable was heated up by a poor connection at the other end.

Once you find the real hot spot, remove the cable (After switching off unless you like alternator jobs) and fill the inside of the terminal with solder. You will need to use a small blow lamp (Or the gas cooker) to get the terminal hot enough to soak up the solder. Do both ends and the clean up the connection site.
No need to replace the cable or connectors.