Weird electrical/starting issue

[spressomon]

OK...just when I thought I was in calm waters the LC is exibiting strange behavior that has me stumped: Turn the key to start and zippo...nada...nothing; not even the dash lights come on either at the 'ACC' position nor the 'Start' position of the key/ignition switch. Jump from the second battery and it fires to life just like it should. Had the batteries bench/load tested and they test fine. Cables are all A-OK (all less than a year old). So other than something REAL esoteric I am thinking one or more of the following:

Starter relay
Starter (although no clicking or other strange behavior...works perfect with a jump).

Anyone have similar experience or have good advice?

Thanks!

 

[100 TD]

Battery terminal corrosion! (or a bad connection)If a car jumps then there is nothing wrong with its electrical starting circuit. When the car is jumped you power the normal circuits down the normal cables as long as you jump on the battery terminals), you are just replacing your battery in effect. Therefore when you had the battery tested the clamps create enough pressure to make a connection through the terminal and corrosion. Remove terminals and wire brush terminals and posts, clean terminals out with a scouring pad or battery terminal wire brush. Get them perferctly clean. Some corrosion is clear so make sure the is no residue left inside the terminals. Remove the bolt that clamps the terminal and make sure it screws down all the way, a lot of times corrosion gets on the bolt and stops you from doing it up properly. Ckeck all lugs coming from the terminal, clean them, and where they make contact with the terminal. Inspect your ground lead for tightness where it is attached to the chassis and check for corrosion or a crack in the terminal. If you jumped on the positive terminal and ground to the engine block, checking the ground strap connections ensure there is not a broken wire in the ground circuit. EDIT I should have said that the ground probably goes to the engine then back to the chassis on these, not 100% sure, but you need to check all ground points generally if you or anyone else is having similar problems

 

[hoser]

Just to be sure it isn't the main battery, what if you swap batteries--put the aux battery in place of the main battery?

 

[100 TD]

Just to be sure it isn't the main battery, what if you swap batteries--put the aux battery in place of the main battery?

In my reply above I assumed(I should never) that the batteries were load tested seperately and correctly, I also didn't read correctly that it had been jumped by an auxilliary battery in the vehicle. If this was done with a switch or solenoid, it still comes back to no power to the vehicle from the main battery so I say corrosion or bad connection again.

 

[100 TD]

Another thing that points to a bad battery connection, you said there are no dashlights at ACC or IGN switch position, but it jumps OK. Therefore there is no power getting onto the power cables to turn on the ACC relay and IGN relay from the main battery. You can test with a multimeter on the wiring going away from the battery terminal. You may have 12 ~ 13 volts there or you may not. If you have 12 volts on the cables, get someone to turn the IGN key on, I expect you will see the voltage dissappear as the tiny bit of load will be enough to drain the voltage down so there is none there due to the high resistance of the bad connection. (The high resistance of the bad connection may allow voltage to be detected, but will not allow current to flow when any load is put on it)

 

[hoser]

Inspect your ground lead for tightness where it is attached to the chassis and check for corrosion or a crack in the terminal.

Good point, a bad ground on the main battery would cause those symtoms. The Aux battery has its own ground to the chassis, so when you jump it, it works.

 

[spressomon]

Just to be sure it isn't the main battery, what if you swap batteries--put the aux battery in place of the main battery?

Good point to try if wiring brushing everything fails.

 

[spressomon]

In my reply above I assumed(I should never) that the batteries were load tested seperately and correctly, I also didn't read correctly that it had been jumped by an auxilliary battery in the vehicle. If this was done with a switch or solenoid, it still comes back to no power to the vehicle from the main battery so I say corrosion or bad connection again.

Jumped aux battery to main battery with jumper cables. Get plenty of spark when the + of aux battery is connected to + of main battery (before connecting - to anything on the main battery side)...so the ground must be solid.

FWIW: Both batteries and cables (except starter cable ) are 1-year old...I installed the felt anti-corrosion washers on the battery posts under the cable clamps when I installed all this at that time...maybe they don't work so well eh?!

 

[100 TD]

As mentioned, if the batteries were tested correctly, swapping them over will do nothing.

Good point to try if wiring brushing everything fails.

 

[100 TD]

The spark show voltage difference, therefore either the battery is flat, or the connection is U/S

Jumped aux battery to main battery with jumper cables. Get plenty of spark when the + of aux battery is connected to + of main battery (before connecting - to anything on the main battery side)...so the ground must be solid.

FWIW: Both batteries and cables (except starter cable ) are 1-year old...I installed the felt anti-corrosion washers on the battery posts under the cable clamps when I installed all this at that time...maybe they don't work so well eh?!

 

[spressomon]

OK...went out and burnished the battery posts and battery cable connections. It appears I have a ground issue. There are two ground cables coming off of the - post of the main battery: One goes to the fender which I burnished as well: The second cable is routed alongside the + cable to the starter; although I can't see where it terminates. Does it terminate at the rear of the block like it appears in the FSM? This would make sense as Toyota engineers seem to like to make some of this stuff (i.e. starter and alternator for instance) as inaccesible as possible

When metering the ground from the battery post to any one of many through bolts along fender, radiator area, etc., the ground is mostly unreliable; I can find 12.8V, which is the same as battery posts and clamps, here and there but not consistently. The fender ground seems like it is a secondary ground and not 100% reliable(?). So I am assuming the main ground issue is with the ground that terminates at the rear of the block(?).

If you don't like to assume...after all the battery connection clean-up the problem still remains as before.

Keep that advice coming guys...its helping me keep this thing out of a shop

 

[100 TD]

If you don't like to assume...after all the battery connection clean-up the problem still remains as before.

Keep that advice coming guys...its helping me keep this thing out of a shop

Well I did state either battery connection or ground connection!

No matter what we are really only talking about 2 or 3 connection points. The battery connections (positive and negative) or the ground connection on the engine and or chassis. (This is only correct if you don't have a stuffed battery, I am still assuming your battery is OK, becuase you have said so.) However if you can jump start directly on the main battery, positive and negative (as long as you disconnect your ground on the auxilliary battery to where ever it grounds) and it fires up then you don't have a ground problem, you have a bad connection or a stuffed battery. If it doesn't start in this instance there is a ground problem in you main battery circuit.

 

[100 TD]

Spresso, PM me you phone number

 

[100 TD]

If you stick a jumper cable direct from the main battery ground terminal to the engine block and the other jumper lead direct from your ground battery terminal to the chassis somewhere, you should be able to start it as this is replacing your broken ground. (If you don't have a stuffed battery that is).

 

[100 TD]

Hey Spresso

What was the end result/fault?

 

[spressomon]

I had two issues...a bad aux battery which was replaced under warranty and a bad ground on the second battery. Got everything back together and was wheel'n yesterday. Thank you for your very useful tips!!!

Dan

 

[hoser]

Glad you found the problem(s). For the record, which brand was the defective aux battery?

 

[100 TD]

Please clarify for me, you say you had a bad aux battery, I thought you could start off the aux and not the main? Was it the main or the aux battery with the crook ground?

 

[LXPearl]

It sounds like when the jumpers were connected, a good battery became connected to the bad one with a good ground, and started.

 

[spressomon]

Please clarify for me, you say you had a bad aux battery, I thought you could start off the aux and not the main? Was it the main or the aux battery with the crook ground?

Actually both. When I installed the aux battery in my haste I forgot to ground to motor and the chassis ground was not real good because of the fender paint. And after I thoroughly (read thoroughly!) cleaned and tightened the main battery ground and had the aux battery swapped for new the entire system works like it should (and has for the past year up to a couple weeks ago). This all started after a good day of winching...so it looks like a couple different issues raised their collective ugly heads at the same time...to make diagnosis that much harder of course. I'll be the first to admit my area of unexpertise is electrical...I can usually get by but it takes more thought and concentration that the other mods I do.