3rd & 4th Generation (1992–1996 & 1997–2001)Toyota Camry Discussion for years: 1992-1996 & 1997-2001
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The past two times I have tried to start the car, the lights and dash have come on fine, but as soon as I turn to ignition everything goes completely dead. So, I thought to myself, bad battery (even though I got the battery a year ago).
I took it to Firestone, and they said they tested the electrical system and it works fine. They said that after testing the system, they just pushed down on the positive terminal clamp and the car started right up. Apparently the clamps can expand with heat and age and no longer carry sufficient current. My question is, how could the battery terminal be "connected enough" to run the lights and stuff in the cab, but not "connected enough" to start the engine? Is the voltage output somehow related to the tightness of the clamp? That just doesnt seem to make sense to me. My impression is that the current will travel pretty much the same as long as the terminals are at least touching somewhat. Anyone able to confirm or deny this?
And secondly, I bought a new clamp, but it doesn't look anything like the clamp that is on there now. Are there different clamps that connect in different ways?
They would be correct. In fact, I've seen cases where you couldn't tighten the terminal any more yet there was too much resistance in the connection to allow starting amps to flow. It would require removing the terminal and wiping off a thin clear 'film' which can build up. (I'm not talking about blue/green corrosion- just a 'wet-looking' film.) Explaining current flow however, is too complicated to get into here. (There's still some argument as to if it flows + to - or - to +. ) As for Part Two, yes, there are several different styles of clamps. They include side-mount and top-post and some clamp to a single wire (or maybe more) while some have a wing nut and stud for multiple wires and even combinations of both.
If you have access to an instrument called a voltmeter, you can actually measure the voltage between the metal cable clamp and the metal battery post, at either the positive or negative battery terminals. If this voltage measurement is anything other 0.0, then you have a faulty, or dirty, clamp to post connection. The use of a special wire terminal brush is recommended to insure that both the battery post and the cable clamp are clean, if not shiny, prior to tightening the clamp bolts. The lead material of the battery posts is given to oxidizing quickly, even if just exposed to air. For the best possible electrical connection, it would be advisable to wire brush the battery post and also the cable clamp connection surface just prior to assembly, and torquing the clamp bolt. ... If you have a side terminal battery, a plain small wire brush is useful for this purpose.
... for the voltmeter test to actually work, you probably need to have some load current going, like turning on the headlights.
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98 Camry LE, 2.2L, automatic
50k miles, drop in K&N A/F recent timing belt, water pump
...My question is, how could the battery terminal be "connected enough" to run the lights and stuff in the cab, but not "connected enough" to start the engine? Is the voltage output somehow related to the tightness of the clamp? That just doesnt seem to make sense to me. My impression is that the current will travel pretty much the same as long as the terminals are at least touching somewhat. Anyone able to confirm or deny this?
More contact = more surface area = more current flow. Current flow becomes restricted under smaller gauge wires. Current does travel in the same direction, but there will not be enough flow if the contact is loose. Think of an analogy about a hallway. With a wide hallway, more people can pass through. However with a narrow hallway, less people will pass through. So overall, your engine requires much more starting power than your lights do.
Make sure your terminals (and clamps) are also clean for good contact. Any oxide, rust or corrosion can be easily taken off using a battery terminal cleaner. Once done, I think you're supposed to apply a certain chemical (to prevent corrosion) before putting the clamp back on. Once done, put on the clamp and tighten that sucker until it doesn't move at all. Any excess or ugly-looking stuff (such as oxide or corrosion) acts like resistance. And you know more resistance = less current flow.
Quote:
Originally Posted by numberforty1
And secondly, I bought a new clamp, but it doesn't look anything like the clamp that is on there now. Are there different clamps that connect in different ways?
The usual existing clamp is the universal type. There are several other adaptors to use (especially for car audio equipment), so you may have to browse a local car store (such as Kragen or Autozone) until you find one that suits your taste. Worst case scenario, just buy the clamp at the dealership.
Just shim the clamp. Any conductive piece of metal will do, a crimp on connector, etc. You can always take a hammer and smash a penny flat, and this will work fine.
Yea I gotta agree with Dave's and Blue fusion about the whole flow part of this conversation. There are two beliefs on the path that current flows no one has been able to prove it yet. If it was - to +, lightning would only strike from the earth to the sky. It goes both ways. Im in school for Auto tech so its pretty fresh in my mind too lol, Definitely just replace your battery terminals though and it should be fine. If you cant figure out how to do it yourself, Take it to a shop. Should only charge you maybe 15 dollars to put them on for you.
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Loose Terminal Clamp Causing No Start?
) As for Part Two, yes, there are several different styles of clamps. They include side-mount and top-post and some clamp to a single wire (or maybe more) while some have a wing nut and stud for multiple wires and even combinations of both.
recent timing belt, water pump
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