Chevy & GMC Vans

Ok so i had a feeling i had a loose wire somewheree else this moring confirmed it. I was driving to work and my voltage dropped to 12 while at a light drove a little while hit 11.9 hit a pot hole came up to 13.6 and was steady there till the next light sat at 13.4 then dropped to 12 again. Light changed put my foot to the floor and took of like a bat outta hell voltage came back up to normal and stayed within' range the rest of the way to work.

I'm going to pull the cables off the batt when i get home and clean them up, and try and check the lead on the alt to see if it's loose.
Any where else i should look i'd rather not do the drive to neco with my voltage gauge bouncing around.

PS. i was using my head unit to watch the voltage much more accurate then the stupid needle

HMB
Cobra

Have a look at the POS nut that is located behind the BATT on the firewall ( may or may not be under a red cap ) make sure its snug as well.

that reminds me is there a way to get inside the rubber ends on the batt cables i'm sure it's not pretty in there

Cobra wrote:that reminds me is there a way to get inside the rubber ends on the batt cables i'm sure it's not pretty in there

You talkin bout the hoods on the ends ( pics would be nice lol )

pics eh...? since i'm at work this is the best i can do http://eaccess.smpcorp.com/eCatalogs/ST ... rt=A73-0HD

When I replaced a batt studd last year i just used a wire brush to clean up that copper ring connection inside the rubber, I doubt there is any corrosion inside of that rubber providing it was made properly.

Loose wire/connection could be on the battery. Could also be on your van's alternator wiring or your internal alternator parts as well.

As a suggestion, start your van, disconnect the altnerator wire (that feeds onto your battery "+" leads) and with Digital meter still connected between Alternator charge wire and battery "+" post, give your vehicle some "bumps". Yes. I'm serious. Jump up/down on its bumper, perhaps do some sudden sideway pushes against its front bumper as well. If your Volt Meter's needle goes "nuts" during the bumps, your alternator could be shot. Most of the time, an alternator works or doesn't work. But sometimes (on rare occasions), it can be a between state - that can change with road bumps.

BTW: Between range of 13.2 to 14.4 (with steady needle on D-Volt meter ) from your alterantor charge wire is normal.

Hope this elimination test helps as well..

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Also check the connection at the starter. This is where the charge lead from the alternator goes. Now may be a great time to do the "Big 3" electrical upgrade.

i'm sure the BIG 3 upgrade would eliminate the problem but i'm not going to do it this time... (i have other plans about those leads) i didn't get to look at it much last night family had me running around but it didn't seem to be the connectiong on my battery. The problem didn't show up at all tho, this morning i started it and it was at 12 did my normal petal to the metal to make it outta my drive way and came back to normal. I'll be checking the alt and following the leads hopefully i find it

Edit:just came out from under it (put skid plate back on) alt lead was secure on starter and alt connection was in decent shape pulled the battery leads..... i'll post a couple pics after i upload them just wow.

ok i started it up voltage looked fine reved it up still fine going to go for a test drive soon to seem if the problem is gone.I pulled the cables off and was amazed the vehicle still ran heres some pics

the insides of the boots weren't pretty either

Neg before i cleaned it not too bad...

Pos i don't think it's every really been clean yes it is white

oh and the battery post was intresting stuff feel off when i pulled the cables off

Be sure to coat the terminals with something like No-Alox or Penetrox. These are used on electrical connections to prevent corrosion like you had.

i seem to have subjugated (did i spell that right?) the problem it didn't show up on the test drive last night or trip to wor this morning.
i had some dielectric grease laying around intended to put it on there but forgot... those 2 you listed i've never heard of going to look into it tho.
OFF-topic:i swear the skid plate changes the way the van handles.... i may be on crack tho