Very dim battery light?

[ITWrencher]

So I finished the head gaskets on our 2002 SR5 Sport yesterday. It seems to be better than ever and a very tough lesson for me to learn not using Toyota OEM parts for a major repair.

In any event I was running the truck after the repair and watching all the indicators on the dash etc. I noticed that the battery light was very dimly lit and would just stay that way regardless of rpm’s? I got out the Fluke 88 and checked the alternator output and it read 14.2-14.4 VDC consistently. So how does the battery light function? I haven’t yet dove into the FSM and was hoping someone here might be able to point me in the direction of what might be going on?

The truck definitely needs a new battery but when I was at Napa and asked how much it was for a new battery the guy told me $200……….:wow2: It’s been a while since I bought a battery so I was hit with serious sticker shock and decided to hold off on the battery temporarily. So where is a good place to get a decent battery at a reasonable price or is that a pipe dream? If I have to spend that much I’m leaning towards just spending a little more and getting an Optima or similar high performance battery.

 

[jgue467]

A little less shocking....
Robot or human?

What is the overnight first thing before starting in the morning voltage of the batt? Cables good and tight?

 

[Pyral]

So I finished the head gaskets on our 2002 SR5 Sport yesterday. It seems to be better than ever and a very tough lesson for me to learn not using Toyota OEM parts for a major repair.

In any event I was running the truck after the repair and watching all the indicators on the dash etc. I noticed that the battery light was very dimly lit and would just stay that way regardless of rpm’s? I got out the Fluke 88 and checked the alternator output and it read 14.2-14.4 VDC consistently. So how does the battery light function? I haven’t yet dove into the FSM and was hoping someone here might be able to point me in the direction of what might be going on?

The truck definitely needs a new battery but when I was at Napa and asked how much it was for a new battery the guy told me $200……….:wow2: It’s been a while since I bought a battery so I was hit with serious sticker shock and decided to hold off on the battery temporarily. So where is a good place to get a decent battery at a reasonable price or is that a pipe dream? If I have to spend that much I’m leaning towards just spending a little more and getting an Optima or similar high performance battery.

The premium Optima batteries aren’t worth it anymore from what I read. Most of the battery brands like EverStart, DieHard, Duralast, Interstate, etc. are made by 2 companies: Johnson Controls and East Penn. The OEMs might be different, but in general they are basically the same because they come from the same place.

Project Farm did a comparison years ago and there wasn’t a big difference between price. What matters is that you get the newest made battery you can and don’t let it discharge completely.

 

[3bears]

there are several grounds and I believe there is one that goes from pass side head or near head to firewall. Maybe that one is missed

 

[ITWrencher]

Well I appreciate the advice very much. I read something online I think it was from this forum about LED dash lights being the culprit. So I pulled the cluster and checked the battery light bulb and sure enough it had one of the new LED’s I bought in it. So I swapped it out for the original incandescent bulb and no more dimly lit battery light. Go figure??? The 4Runner does still need a battery so tomorrow I’m going to go to Walmart (something I almost never do) and pickup their Everstart AGM battery for $180 with a 4 year free replacement warranty.

 

[wcjeep]

Costco also has decent battery prices on Lead Acid and AGM.

 

[brillo_76]

Well I appreciate the advice very much. I read something online I think it was from this forum about LED dash lights being the culprit. So I pulled the cluster and checked the battery light bulb and sure enough it had one of the new LED’s I bought in it. So I swapped it out for the original incandescent bulb and no more dimly lit battery light. Go figure??? The 4Runner does still need a battery so tomorrow I’m going to go to Walmart (something I almost never do) and pickup their Everstart AGM battery for $180 with a 4 year free replacement warranty.

That's another issue I seen with LED bulbs. I think there is really only a handful of battery mfg left. 5 or so, the rest just throw their brand on them. Not sure how many do AGM.

I only use LED in the doom lights, possibly 2 of the 3 brake lights and backup lights that about it. I only do that so the rear lights are brighter. Sadly many circuits seem to not play well with LEDS in these rigs. Headlights you have to use a resister led bulb or a resister so your high beam indicator works. Led in all 3 brakes lights interfere with I think cruise (not 100% on that one) Lots of people change them out then start having bizarre issues. I am glad if my lights just work...LOL

 

[2TH4IST]

LED in the 3rd brake light will cause the abs light to come on. It senses a open circuit as if a bulb is out.

I have this same issue with my switch pro dimming function. I used the parking light circuit to activate it, but as I have led's all around it leaves 5-7 volts on the circuit and then activates the dimming function. It's a PITA to deal with, but they work oh so good.