So since it's freezing up here, I've been helping everybody get their vehicles running.

My roommate's car was dead this morning, so I tried to jump him. I connected my cables to the remote battery terminals like you're supposed to, but I couldn't get any current from them. I decided it was a bad ground, so I readjusted cables, etc. with no luck. All I had for diagnostic equipment was a test light, and it DID glow brightly at the ends of the jumper cables.

However, in order to get enough amperage to start his car, I had to connect my cables directly to the passenger side battery.

What gives?

So since it's freezing up here, I've been helping everybody get their vehicles running.

My roommate's car was dead this morning, so I tried to jump him. I connected my cables to the remote battery terminals like you're supposed to, but I couldn't get any current from them. I decided it was a bad ground, so I readjusted cables, etc. with no luck. All I had for diagnostic equipment was a test light, and it DID glow brightly at the ends of the jumper cables.

However, in order to get enough amperage to start his car, I had to connect my cables directly to the passenger side battery.

What gives?
Same here

Interesting...it seems I don't have a "problem." I definitely have current there, but it obviously isn't full amperage.

Is the current reduced at the junction in some way?

Is there some way that this junction is meant only for receiving a jump and not giving one--a diode of sorts?

That is wierd....when i used to use my truck for work i boosted lots of guys using that remote setup with no problems......

Weird for sure, Tys! I wonder if it's an LLY vs. LB7 thing or if I definitely have a problem.

My batteries are good, and I'm sure I'm getting a good ground or my test light wouldn't have worked.

Funny part is that this is where GM recommends a guy to hook up the cables.....):h Might wanna take her in for a check up

I know it...what puzzles me is that I have some current there but I'm not sure how much. I may have a chance to pull it in our school shop tomorrow to do a load test at the remote.

I have jumped people in both trucks without problems using the red box for the connections. I just wish the connection point was beefier for the cables to clamp on.

Have you tried different cables? Maybe your cable has a crimp in it or a loose connection.

keep in mind too, your buddies battery might be about shot. this will make more of a draw on your truck. so, you could be getting a better hook at the battery if there is enough draw from his car. granted it isn't alot difference but could be the extra it needed. you loose some amperage in cabling and every splice there is. good luck ;)

I think this was covered here a little while back. It seems that on some trucks you have to take apart that ground and sand the paint off of where it mounts. I have jumper cables that you are supposed to connect directly to the batteries since they have some sort of microchip in them. They disconnect in the middle and have lights on them to show you that you can jump the other vehicle before connecting them together. Pretty neat.

I always go right to the battery. I've never had much luck with the remote terminal.

I've only jumped people a couple of times, but connecting in the red box and to the ground "paddle" above it spun them babies over like nothing. I DID go to their positive terminal/cable clamp on the battery and to an engine/body ground instead of to both battery cables. If you go to the cables on the recipient battery and it has both a really dead cell AND a poor ground that could explain some of the problem (including why the battery went dead).

All I had for diagnostic equipment was a test light, and it DID glow brightly at the ends of the jumper cables.

However, in order to get enough amperage to start his car, I had to connect my cables directly to the passenger side battery.

What gives?

The test light requires very little current so it will not have the same level of voltage drop as the dead battery at the other end of the jumper cable. A minimal amount of resistance, i.e. paint, loose connection, corrosion, will disable the jumpstart process.

A 20 watt bulb is bright, but it only requires, ~1.5 amps to burn bright. If your bulb dropped voltage .5 volt, it would still be bright at 13.3 volts.
You didnt tell us about the car and how dead the battery was, did the headlights glow, turn over but too slow, click, or nothing. If the starter required 30 amps which is a low number on a cold morning, you would have a 10 volt drop or 3.5 at the terminals, in the above equation, which is probably less than the dead battery in the first place. Remember when you connect, the battery that is dead will also have some draw from your system. The best method to jumpstart is to first have good clamps that arent rusty or corroded, have good wire, I prefer 2 gauge minimum, and take your time. Connect the two cars correctly and give it a minute. The wire has a resistance associated to it also, if you can get the battery up from 11 volts to 12 volts, your gains when you hit the starter are exponential on the current side.

It usually is a poor connection at the "red box" terminal. Take it apart, scrape/sand and clean, reassemble and you should be good to go.

Think of it as trying to use an 18 guage extention cord to run an air compressor; it won't carry the current needed to start the compressor, but would be fine with just a small drill or a light.

Thanks very much guys. His battery was TOTALLY dead--i.e. it wouldn't even run the clock on the radio, etc. When I tested it yesterday, it wouldn't even register on the volt scale I was using. After charging for about three hours, it load tested acceptably on the machine I was using.

I'll try to make it a better connection in the next couple days.

Well the "problem" is solved. The remote ground tab dealy isn't making good ground. It is grounded enough to make the test light come on, but not enough for full amperage.

When I ground to the second alternator braket, all is good based on what the load tester is saying.