Headlights Dim & Heater Blower Loses Power When in Neutral?

So this started last winter as intermittent symptoms but this winter it is every time I'm putting the truck in neutral. Headlights dim way down and damn near blink sometimes, heater blower motor loses a lot of power and sometimes even the heads up display dims and seems to briefly pop a warning.

My thoughts and others think the alternator should be swapped out and this is abnormal. Any suggestions would be useful ammo for bringing for me to bring to the dealership.

*On a side note I did Toyota's long survey and Toyota Corp called me within 2 days, called my dealer and made them call me to setup an appointment to address any and all concerns I may have. (Other issues are rumble strip/driveline and hood separation). It instilled a lil' bit more confidence that Toyota is worth sticking with! (Came from 89' Corolla manual and 89' Corolla All-Track manual).

 

Sounds like an alternator issue. You might check in the engine quickly for corrosion on the leads to the alternator, leads to the battery, etc but thats what it sounds like. Since they have been decent so far to you I would just go in and be nice about it but express that it's inconvenient at best and potentially damaging other electric components like the ecu or the head unit by having the power dip so much

 

One Word. DEALER!!! Don't try and screw with it yourself unless you are out of warranty.

G.

 

I'll be in there later in the spring to pick through the truck. lol I would do it myself, no biggie to me for the work. The principle is I want them to pop a fresh one in there. The less they touch, the better!

Thanks guys!

 

Right on man. I'd say get a brand new one through Toyota, then take your old one and have somebody take it apart and beef it up while you have an extra. Could easily wrap the coils with more copper for better efficiency and install an underdrive pulley to goose a few more rpm out of it and fix whatever was wrong while they're in there

 

That and the hood are the big items I'm going to stick to and not let them brush it off. l have a few rattles but I'm not even going to get into that. Other than that they're going to measure the drive line angles to hopefully correct the rumble strip effect when braking.

 

Isn't this a symtom of a bad voltage regulator?

 

I suspect its the alternator, not the voltage regulator due to the headlights/heater being the main items "losing power". Dash not working looks to be the voltage regulator. I suspect it may have been trying to pop the battery warning then it stopped before it could fully display.

I don't have any of the following:
- Dim/flickering gauges.
- Inaccurate/erratic dash readings.
- Inoperable instrument cluster.

 

I think I will have them check this cause why not! Plus the last few days the fuel consumption bar has been showing consumption while in neutral (manual, bar usually is fully right when in neutral and rolling).

Thanks for the heads up!

 

The alternator and the battery need to be Load Tested. If you have a failing alternator, it will damage the battery. If you have a failing battery, it will kill the alternator.

 

Thanks!

 

@Zoop did you ever figure out the problem. I'm having a similar issue.

 

I haven't had it into the dealer yet to go over. Myself and a few buddies suspect the alternator though. I saw on a TDI forum someone had a similar issue that was caused by the belt having to high of tension and bogging it down. Hopefully I will get it into the dealer in the next few weeks. I'll try to remember to log in and update once I do that!

 

Finally got the truck into the dealer for a few items including the possibly crappy alternator, the hood glue separation, the driveline/rumble strip, howling diff...

I'll post up once I hear whats going to happen! Rolling a Camry for now...

 

Response is that everything checks out and it's a "characteristic of the truck". I think it's bullshit so when I have time I'll be digging in and testing everything. Otherwise I'll rock it till I have to replace the alternator or battery.

 

Thanks for the update.

 

And yeah typical dealership bullshit line

 

I can bet you they'll find the problem when the warranty is up?

I don't understand why Toyota dealers are so reluctant to fix stuff under warranty. They keep nagging me to bring my truck in for it's free Toyota Care. I've told you now 101 times I've already done it at the dealer closer to me, why would a freaking drive and hour and half for a free Toyota care. Update your damn records.

Makes me want to buy another one!

 

Right?! My ODO is 35,620 and they wrote 35,882 on the paperwork. It is bullshit. Even after I informed them I have the 75,000/7yr platinum warranty. I told them I'll be back when the alt or the battery craps out. Hopefully testing it in the next few weeks independently.

 

Any number of things can cause your issue.

For the basics, simply put a DVM across the battery terminals. If you're seeing 14.2 or more, alternator is fine.

Using the same DVM in the same location, have someone crank the truck. If you don't drop below ~10v instantanious, the battery is ok. But a parts house can load test in vehicle for free if you wish.

Low idle can cause your situation. What is the tach showing?

The refereed to Voltage regulator moved from being a firewall mounted component to built in the alternator to now being part of the ECU in most marquees.

Idle step up sensor can be off kilter. This steps up idle when load (like turning on AC or headlights) is sensed.

But the real deal is that you've had it checked out. Hopefully your paperwork shows your 'dimming' issue as a complaint. So if a warrantied part does fail, it has been documented. (batteries are pretty limited on warranty)

Under very, very, rare conditions. As in almost hen's teeth rare.