Dimming Lights, window use

[AllTrac]

Here is what I have going on and my guess is that the alternator or battery is a little undersized. When I am driving at night and use my windows my lights noticeably dim. That really bothers me to no end. So what is the deal? Do the lights draw to much wattage, is the battery undersized or is it a alternator thing? Is there anything that can be done?

[Carbon]

I would get your battery "load tested".

[JonRav4]

Originally Posted by Carbon

I would get your battery "load tested".

...along with the alternator.

[hd72m]

I would also run extra grounds to frame and body,it is cheap to do and really helps,the RAV4 4.1s have a weak ground and the older they get the worse they get.

[Carbon]

Originally Posted by hd72m

I would also run extra grounds to frame and body,it is cheap to do and really helps,the RAV4 4.1s have a weak ground and the older they get the worse they get.

Sounds good, but you did not say where to run the grounds from.... engine block maybe?

[hd72m]

You can by special battery terminals and connectors that are purity but I done it the cheap way. I got one good connector,crimped and soldered 2 bigger wires and put it on neg battery terminal. Run one wire to the body,I put it on fire wall. Do not drill to deep or use to long of screw,I used self tapping screw. Clean all paint where screw will go and I also used a star washer and shot it with clear paint to keep it from rusting. Run other to the motor I think I used the bracket bolt for alt.
Some people run wires to starter,alt,throttlebody and transaxle also.
It will not give you 20 extra horsepower but it does help,I notice it most on take off with air on and putting windows up-dn with key off.

[AllTrac]

I mean the battery sounds healthy but I will get it load tested today. Grounds, never even thought about that. Is their a kit for the Rav4?

[Carbon]

1. I think battery getting weak is the most probable. Auto parts dealers will often perform the test or will loan you a tester free. They are hoping that you will buy the replacement battery from them, which is reasonable. If the test is low, I would immediately replace the battery if it is in service for five years. I might replace the battery after 5 years regardless of the test if a failed battery on the coldest day in January would be much of a problem for you.
2. If the load test result is bad, it is common to charge the battery and retest. If that retest is much better, then the alternator would be suspect. It is possible to have a weak alternator and a battery that should be replaced.
3. You can test for the need of supplementary ground wires by connecting a voltmeter between the negative terminal of the battery and the chassis. With the key off, turn on the lights. Look for an excessive voltage across the meter. The problem is, what is excessive? TSP Electricity 102 says 50 mv is excessive. That's a little lower than I was thinking.

While cranking, I would expect maybe 500 mv to be acceptable. In that case, measure from the negative battery terminal to the engine block.

I don't really know what should be the normal voltage drop. If you post some numbers, maybe somebody else will duplicate your measurement.

[hd72m]

You can buy the clamps for the battery and wires with connectors on them but do not know of any made to fit kits.
I would just look to see where you want to run them and measure how much wire you need and get connectors for the wires.
Use volt meter to test alternator on battery and speed motor it should go to at least 13.5 volts hopefully 14 or 14.5 volts

[JonRav4]

This has been discussed a lot on the forum in the past. There are kits, both off-the-shelf and DIY. Search is your friend.