Electrical issue

Multiple issues here.
1- vehicle not charging. Battery is brand new. Removed the alternator and it bench tested good.
Middle wire, y/g, on the voltage regulator has zero voltage.
2- The windshield had leaked according to previous owner. Nothing works on the gauge cluster except the door open light. The interior fan also doesn't turn on.

I had read about the battery indicator light works as a "switch" to tell the alternator to send power to the battery/ electrical system. This inclined me to remove the instrument cluster. Upon doing so I found some pretty good corrosion on the solder joints and screws. I cleaned with electrical spray cleaner and lightly scrubbed with an old tooth brush. Appeared to clean up fairly well but upon reinstalling nothing changed. I'm leaning towards the cluster being the culprit but that doesn't answer the fan not working. Also am having trouble finding which wires power the instrument cluster. I have a Haynes manual but it doesn't show the instrument cluster. I'd like to see if the dash is getting power. Thanks to any and all who might have thoughts on this!

 

When you bench tested the alternator, did you test it under a dummy load? When the vehicle is running, does the voltage jump up to 13.5-14V? Someone here probably has the FSM to show you.

 

Thanks for responding. I took it to O'REILLY auto parts and they put it on the machine with the belt attached. It does not increase in voltage but my understanding is that the battery indicator lights acts as a switch to turn the alternator "on"? Maybe I'm misunderstanding this.

 

Did you check the 100A/140A alternator fuse in the under hood fuse/relay box? It's one of the square clear-top ones. They're a BITCH to pull out.

Oh, and where's the leaking happening? If it's in the passenger front floorboard, it's probably from the cowl. Check the 'Definitive Leak Thread' in the sticky thread section for more info. Cheap/easy fix.

EDIT: Missed a number in the fuse amperage. Check this thread and see what another member dealt with - https://www.tundras.com/threads/charging-alternator-problems.97131/

 

Hi Shifty, I did check that fuse visually. I didn't pull it to check resistance. I will do that. Also the leak was a cracked windshield that was replaced.

Thanks!

 

You see what the other guy's fuse looked like, that happens sometimes.

It's not uncommon for corrosion to happen internal to the cables, and since you've said you know how to check for continuity/resistance, I presume you have a DMM and know how to use it. In which case, you should also take a sec to test the runs between the fuse/relay box, the battery, and the alternator.

 

Hi Shifty,

You weren't kidding. Quite the process on that fuse. I got it out and had .3 ohms. I believe that's well within the specs. I will try those other ideas. I'm really leaning towards that instrument cluster as it was pretty corroded and I would imagine it could short something. Tested across the gauge fuse in the truck and was getting 12+ on both sides with the key on. Any thoughts on what wires are the power to the gauges? I have a Haynes manual but it doesn't show the wiring that specifically.

 

Sorry, thought I linked this but it was in another thread. Here's the EWD archive: https://www.tundras.com/threads/ultimate-tundra-wiring-diagrams-collection.81448/

That should help you trace wiring. I'll point you to this specific thread, you indicated it was a known windshield crack causing the leak ... here's what another member found, and something you can look specifically for on driver side leaks: https://www.tundras.com/threads/02-tundra-electrical-problems.45605/#post-1174202

We've also seen similar with the ECM for passenger side leaks: https://www.tundras.com/threads/time-to-ask-for-help-truck-wont-fire.108227/#post-2791821

I realize it's a bit of digging, but if you're convinced it's on the cab side, there are what I'd say are your two main culprits.

 

Excellent! I'll take a look at that too. Thanks a lot!

 

After a look i too have the nasty blue corrosion in the fuse panel. I'd like to understand how Elvis split that open. I thankfully don't have any broken pins but pretty sure, I'm guessing, I need a new fuse panel and instrument cluster. At least it's moving forward!!

 

Sorry to hear it, but also not 100% surprised.

That said, there are a few different fuseboxes. They're different between cab types, and even between years. You may find the correct replacement part number on your old part. Normally part numbers are in a 10-digit format, like:

ABCDE-FGHIJ, for example: 43430-0C010​

It's common for the part number to always have that "-0c0" part in it. Sometimes the part number may have a few extra characters on the 2nd half.

If you need help looking up the part number online, gimme a shout. If you find the part number, but it doesn't show up in the system, paste it here and I'll do some sleuthing - they may've changed the part number.

 

Thankfully I've found both very near by! Unfortunately these 2 connectors have me stumped.

 

This is why I always take photos before removing, then use tape to number the position from 1-20 left to right, then top to bottom.

Just to ask: Old part and new part are 100% identical?

Oh, and which cab do you have?

 

This is still the old part. If you look i have all the connectors labeled, been there before, lol! I'm stumped on how to remove these last 2. Feel silly not being able to figure it out. I want to bring this old one with to verify everything is identical at the yard.

 

Ok, got the replacement fuse panel today. Matching parts number and also a new gauge cluster. Tmrw I'm hoping to get it put back together. I'll report back my findings!

 

Totally forgot you'd asked about taking off those two connectors. I take it you figured it out?

 

I did! Just had to stare at it for a minute. We'll see if this is ALL the issues. Fingers crossed.

 

Good afternoon! Good news!! After replacing the gauge cluster and the interior fuse panel as well as splicing in one of the rotted connectors i now have a truck that works correctly! Dash, fan all dash lights and the charging system. Thanks for the tips. The only thing I think I need now is a new oil pressure sending unit. Erratic readings from the oil pressure gauge. Seen this one before on other trucks. Gonna have a happy kid on Thanksgiving!! Happy holidays to all!!

 

Happy holidays, thanks for updating your post.

@JLC73 one quick favor to ask - can you crack open your old fuse panel and share some pics of the inside? Just curious to see how bad it was corroded. The info may end up being useful for the next guy rolling through for help

 

Yep. Sure can. It wasn't as bad as the other gentleman's but you could see remnants of a "fire" on the aluminum. Will post tmrw.

 

I’m going to chime in and ask if OP Replaced the connectors with corrosion in them that connect to the fuse box? Also, we’re you able to fix the leaks?

thanks!!