Luckily I live next to a hotel and caught a cab to work. Tried to start it this morning and it immediately and completely died electrically. There's a tiny bit of power going to the seat belt light but that's it. No interior lights or anything.

I managed to reset whatever it was by disconnecting and reconnecting the battery after work. Interior lights came on, but as soon as I tried to turn the key it died again. So I'm thinking it's a relay somewhere.

Going to go troubleshooting and poke at relays in particular, but just curious to know if anyone has an idea what it might be. Going to try to clean and reconnect the battery terminals (again) but since they're pretty well coated in dieletric grease I don't think that's it this time.

ShipFixer wrote:Luckily I live next to a hotel and caught a cab to work. Tried to start it this morning and it immediately and completely died electrically. There's a tiny bit of power going to the seat belt light but that's it. No interior lights or anything.

I managed to reset whatever it was by disconnecting and reconnecting the battery after work. Interior lights came on, but as soon as I tried to turn the key it died again. So I'm thinking it's a relay somewhere.

Going to go troubleshooting and poke at relays in particular, but just curious to know if anyone has an idea what it might be. Going to try to clean and reconnect the battery terminals (again) but since they're pretty well coated in dieletric grease I don't think that's it this time.

what year is the truck, mileage, and what is the history on the battery?
from what you've described, it smacks of battery failure.

2005 with 82K miles. Battery is less than a year old (replaced after deployment) and a slightly higher rated CCA model. No signs of a "dying" battery either last night or just before...but who knows. No clicking from the starter, no attempt to turn over, just went dark.

Found my multimeter, going to go check everything now and hope it's something easy.

Battery has 12.6V, that's not it...

ShipFixer wrote:Battery has 12.6V, that's not it...

You can't diagnose based on that... Only under load can the number be reliable... Defective year old batteries happen sometimes... Besides if it's only a year old then it's still under warranty and may even be free replacement at this stage... Let the vendor/retailer check it out.

Yeah, um, have to get the truck started to test under load, and I'm not walking it to Walmart But with 12.6V I should have gotten something out of it. This wasn't a dying battery, it was *poof* nothing.

Anyway, it wasn't the battery. It was the terminal again. Sanded to bright metal, cinched down, regreased...

The battery holder had worked loose so I'm thinking maybe it let the terminal wiggle and allow dielectric grease in between. It was a little too easy to loosen the terminals. Since I just went through this a little while ago I was pretty sure that couldn't be it. But...whatever, it works again...

This experience shows that a voltage reading not under load does not prove the battery is OK. Terminals or internal connections between the 6 -2.1V cells can fail.

A test I have used in the past is to observe the brightness of the interior lights. Does it dim or go out when headlamps turned on? If YES, then the battery or connections are bad. 2 headlamps = ~8-10 amps.

In this cold spell, the battery was slow to crank. Overnight V never came close to 12.6V. I bought it 36 months ago. Had a 70mo warranty label, but only an 18 mo free replacement. The pro-rated amount ended up to $1-2 credit toward new purchase. Problem was I bought it so cheap thru a friend at a parts place. Guess you can’t expect more than 3 yr out of a battery today. Often thought about how hot it gets under the hood in the summertime after use. Wasn’t it the old VW Beetle that kept the battery under the back seat and it lasted forever? Well so much for progress.

you may want to invest in some new battery terminals on the end of your cables. the ones that came on my truck are pretty wimpy and will be gone at next battery replacement.

ShipFixer wrote:Yeah, um, have to get the truck started to test under load, and I'm not walking it to Walmart But with 12.6V I should have gotten something out of it. This wasn't a dying battery, it was *poof* nothing.

Anyway, it wasn't the battery. It was the terminal again. Sanded to bright metal, cinched down, regreased...

The battery holder had worked loose so I'm thinking maybe it let the terminal wiggle and allow dielectric grease in between. It was a little too easy to loosen the terminals. Since I just went through this a little while ago I was pretty sure that couldn't be it. But...whatever, it works again...

It's on the list of things to do now. (Well, it was already there after last summer.) This is unfortunately my second Nissan with lame terminal issues.

Glad you got it sorted! I'll be on the lookout for this if mine fails to start...

aadadams wrote:Glad you got it sorted! I'll be on the lookout for this if mine fails to start...

I'm thinking I'm going to start checking the positive terminal with a wrench quarterly. "Mechanically feeble" seems to be a design feature.

The terminals stretch over time. You can replace them, or, if you're lazy/have no time like me, you can stick a nail/suitable wedge between the post and the terminal clamp. This makes it a lot tighter and provides better contact on most of the battery post.

I've had an issue occasionally with my 05, which also seems to be relay related. Happened in the car wash last winter, and 1-2 times since. It seems that if battery capacity goes below a certain level and the auto headlights are on, it goes into some kind of funky state with relays clicking until the battery is discharged or disconnected. Usually disconnecting and allowing it to recover for 15-30 minutes will allow you to start, but you must ensure everything else is off including those pesky headlights!