Odd electrical problems

steveyblack

Member
Jun 21, 2007
529
0
16
33
Nj
OK so within the last week my car has been acting up.

When cold, the car Starts up fine. When the brakes are hit there is no dimming of the lights and radio. acts normal. Its when its warm when it starts to act up. When I hit the brakes the lights dim bad and my radio cuts out completely. If the brakes are after the dimming goes away. Idle is affected when the lights dim too. When I shut the car off, it has a very hard time restarting if ive driven for a while. I cleaned my ground in the trunk since my batter is back there and it barely helped. Im leaning towards either another ground or possibly my battery. just wanna hear your 2 cents on this.
 

Nick M

Black Rifles Matter
Sep 9, 2005
8,894
38
48
U.S.
www.ebay.com
Is your battery light coming on while this is happening? That means the battery is being discharged.

Do you have high quality and acceptable gauge wire going to the back? No corrosion? Is the battery load tested lately? Charging system load tested?
 

steveyblack

Member
Jun 21, 2007
529
0
16
33
Nj
Nick M;1612879 said:
Is your battery light coming on while this is happening? That means the battery is being discharged.

Do you have high quality and acceptable gauge wire going to the back? No corrosion? Is the battery load tested lately? Charging system load tested?

no battery light in the car since the guage cluster is hacked up. I have 1/0 going to the rear and also a 1/0 ground. Cleaned the grounds. Havent tested the battery load yet and how do I test the charging system? Take the alt off and bring it to autozone or something?
 

metaphysico

Mad Scientist
Jan 2, 2008
428
0
0
44
Gainesville, Georgia
Easy at home test would be check voltage with car running with no loads on, then turn on high beams, brake lights, and blower on high, and check the voltage. If you drop more than say .5v you have a problem. Now .5v drop is on the low end of the spectrum for a problem. Also check the ac voltage from the alternator you should not have more than .7v ac with car running. If you have high ac voltage you have a bad diode and need a new alt. If you voltage drops too much between loaded and non loaded you have a bad regulator or other alt problem and still need to replace it.

What you should also do is test the ohms between the main fuse and the battery post and see how much resistance you have you don't want more than 5 ohms of resistance and on that vital of a circuit I wouldn't even want that much. Lastly when you put in the relocation wires did you use good connectors, ie gold plated ones or lead solder type.
 

Poodles

I play with fire
Jul 22, 2006
16,757
0
0
43
Fort Worth, TX
heat = higher resistance

It's just showing a weakness in your system, now you have to find it by troubleshooting with a meter...
 

Poodles

I play with fire
Jul 22, 2006
16,757
0
0
43
Fort Worth, TX
Also, it sounds like you're running a positive to the back of the car, but the ground is local. The factory has a ground directly from the battery to the block...
 

steveyblack

Member
Jun 21, 2007
529
0
16
33
Nj
Ok sounds like I got alot of work to do to my electrical system. Do you guys recomending running power wires outside the car(Along the frame away from the road) be a good idea? Id also put a plastic sheild over it.

ill get to the multimetering it tomorrow and post up some results!

---------- Post added at 01:15 PM ---------- Previous post was at 01:12 PM ----------

And I have checked all my grounds. The one that goes to frame to engine is also 1/0 but I dont like where I grounded it so ill be changing that too.