skoob

I have a 1992 Pickup. Recently I will go out to start it, I put the key in, lights in the cab stereo starts up. I turn the key further or put my foot on brake then all lights go out, no sounds nothing.
I take foot off brake and all lights come back on. All accessories work. Took the battery out and it was tested as good.
It is a automatic transmission. It has had trouble shifting into park lately. I read somewhere there is a switch that prevents startup if it is not engaged.
Move to neutral would eliminate this, same problem.
If anyone has ideas let me know. I couldn't find anything like it in the forum. The issue is intermittent. This went away for one month and is now back.

Thanks.

RJR

Bad connection somewhere between the battery and the system electrical bus. Works fine with low current draw (stereo, dome light, etc.), but once you add extra load the voltage drops to near zero.

Next time this happens grab your multimeter and clip the (-) lead to the negative terminal of the battery. Then start at the battery and measure the voltage with the system loaded so that the lights are out. If the battery is good it will read 12V or so. As you move away from the battery down the cables and through the fuse box you'll find a spot where the voltage disappears. That's your culprit. Make sure you measure the drops in the ground side as well. The electrical current has to have a return path, so the ground side is just as important as the hot side.

There's a good chance one of your battery cables is badly corroded inside the insulation right next to the battery terminal. It may be hanging on by just a strand or two, but the insulation hides the problem so from the outside it looks just fine.

RAD4Runner

Concur with RJR. Contacts should have shiny metal contacting shiny metal. Gun-metal or grey metal is not good connection.

Odin

skoob

Cool video, he said if a cable gets hot there is resistance, that was noticed on the positive side, I will look closely at the cables and try those tests. Sad thing is the cable is new.

wyoming9

iTrader: (1)

If the shift linkage is out of adjustment it will not allow the neutral safety switch to close in either park or neutral

Though I also think looking at the starting circuit as well is always a good idea.

skoob

You may be on to something, I have found a few articles on that. I will check that also. Thanks for reminding me.
I know I can figure this out. I have been able to get it running in the past.

RAD4Runner

Don't just look. I mentioned "contact" ^^^. Did you check your battery connector? It doesn't matter that your cable is new, if you have corrosion between battery post and the connector.Ask me how I know

wyoming9

iTrader: (1)

Ok !!! How do you know?????

RAD4Runner

LOL! Click link above.

skoob

That was it, very slight corrosion. I took the cables off, cleaned the posts and cable ends. Once i reconnected, truck cranked right up! Awsome. It was only slightly corroded.
Next question I cleaned them only a month ago, how do I prevent it or how can i find out what is causing it.
It sure was exciting to get it going again and it only took 15 minutes.

RJR

First, make sure the connector fits the battery post really tightly with no gaps. A tight fit keeps air, and more importantly, sulphuric acid vapor that vents from the battery, from getting in between the mating surfaces and corroding them. Frequent corrosion and connection problems are a sign of a too loose connector.

The second thing you can do is coat the whole terminal with grease. Any heavy grease, such as wheel bearing grease, or the stuff that's in your grease gun if you lube your own fittings, will work. Again, it keeps air and acid vapors off the connection. There are special purpose coatings you can put on the connections which are less messy, but I just use grease.

(I should add that you want to apply the grease/coating after you assemble the connection. You do not want any coating on the actual mating surfaces, or you'll add resistance just where you don't want it.)

skoob

I have tried the grease trick now I will monitor the situation over time. I really feel the corrosion was the problem. Thanks for everyone's help.

wyoming9

iTrader: (1)

I use the chemically treated washers I buy in containers of 100 for a few dollars

I tried the grease way to messy I tried the anti corrosion sprays again messy the washers work the best for me.

Every time I have the terminals off I put a fresh one on

RAD4Runner

I started using silicone dielectric grease n connections (Permatex brand) to prevent corrosion. When I got my new battery, I put that grease ON the post and ON the connector, then squeezed both together to squeeze grease out of the metal-to-metal contact, then tightened properly. After one year, my connections still look brand-new.

Simply applying grease AFTER connection is tightened will also work because the heat will help make the grease spread where it could.

Silicone grease also makes it very easy to clean connections when you take them apart. Easy to wipe off with minimal residue.

Odin

It doesn't take much with small battery cables and that's why I always recommend going with a bigger cable than normal. Stock would be about 6 gauge and most would say 4 awg is a good replacement/upgrade and 2 awg is plenty big, however I would go with 1 awg or even 1/0.
I went with 1/0 tinned boat cable on mine with copper tinned lugs to help keep corrosion away.

Several years ago I tried smearing a thin film of regular AND hi-temp bearing grease on my battery connectors but found that while it stayed on the terminal after a while most types of grease will allow the oil to drop out and start spreading creating a mess on the top of the battery. You can see the same thing from containers of grease that has been sitting for a long time, the oil starts floating on top. http://www.schaefferoilreps.com/12-1...ehandling.html

Although some people suggest spreading Vaseline on battery connections this is not a good idea because of it's very low melting point.

Rather than hi-temp grease I switched to Silicone grease, also called Dielectric grease or Tune Up grease. I like it so much I stopped using the small tubes of Permatex because I always needed more. I also use it for household and stuff at work. One large tube should last an occasional user a very very long time. I now use
Dow Corning Molykote 111

But I'm also considering using the following

Dynatex 49593


3M 08946


It's also a good idea to use the red and black covers on your battery terminals. One good reason is that any grease tends to collect a bit of dust and dirt so it helps keep that down. It's also a good idea to use the covers to keep battery gasses and water off of the connections. When it comes to corrosion regular lead acid filled battery's produce gasses and they are the worst offender. If you have several wires running to the connector unless you cut holes in the cover the only connector/cover combo that works decent is the military style. This is but a few of the covers that are available.

Regular








Marine








Military

skoob

Thanks, so far so good on terminals. Still clean and starting with no issues.

Odin

It's now all about corrosion PREVENTION.