Intermittent Electrical Problem - Total Power Outage ! Rav 4.1

[Worlds End Stu]

Hi All,

I've recently started getting a weird intermittent problem on my RAV.

Get in the car, turn the key, engine starts to turn over and then all electrical power cuts out killing the engine.

Or... I get in the car and there is no power to start with, ie: no interior lights, no clock, no ignition, NOTHING.

The first couple of times this happened I just jumped in my other car instead and then when I came back to check out the RAV it was working again.

A few months ago I put a new Battery in the wrong way and blew the main 100a fuse. It looked a it of a pain to replace it, so i got the local Toyota garage to replace it and it's only since then this that has started happening. Co-incidence?

The car doesn't get used a great deal and can sometimes go for 3 weeks without the problem happening, or like this week it happens twice in the space of a few days.

The last 2 times this has happened i've popped the bonnet, given the fuse box a thump and it all started working again.

Co-incidence or could it be a bit of an iffy connection since the 100a fuse was replaced?

If it is an iffy connection, why has it never killed the power whilst i've been driving?

Another weird "issue" i've only noticed since the 100a fuse was replaced is that (again) intermittently, if I flash the headlamps or switch them on, the radio cuts out for a couple of seconds. Sometimes it happens, sometimes it doesn't.

Haunted? :-)

Any ideas?

[IanXT4]

I would check all the connections from the Battery to the fuses etc for tightness and corrosion (include the earth side). If you have a poor connection that has a little resistance in it then on low currents (ie driving) it will not drop much voltage, but on high currents such as starting it will drop significant voltage and the cars systems will think the Battery has been disconnected.

If you remember your school physics Voltage = Resistance x Current

When currents get to hundreds of amps you don't need much of a bad connection to drop a large voltage.

Its also possible that your Battery has a problem internally, you can get it tested at your local motor factors.

There are other possibilities but I would start here.

[crofter]

Was'nt there a problem similar to this on another model that was resolved by changing the electrical part of the ignition switch ?

[Worlds End Stu]

Hi All,

I've recently started getting a weird intermittent problem on my RAV.

Get in the car, turn the key, engine starts to turn over and then all electrical power cuts out killing the engine.

Or... I get in the car and there is no power to start with, ie: no interior lights, no clock, no ignition, NOTHING.

The first couple of times this happened I just jumped in my other car instead and then when I came back to check out the RAV it was working again.

A few months ago I put a new battery in the wrong way and blew the main 100a fuse. It looked a it of a pain to replace it, so i got the local Toyota garage to replace it and it's only since then this that has started happening. Co-incidence?

The car doesn't get used a great deal and can sometimes go for 3 weeks without the problem happening, or like this week it happens twice in the space of a few days.

The last 2 times this has happened i've popped the bonnet, given the fuse box a thump and it all started working again.

Co-incidence or could it be a bit of an iffy connection since the 100a fuse was replaced?

If it is an iffy connection, why has it never killed the power whilst i've been driving?

Another weird "issue" i've only noticed since the 100a fuse was replaced is that (again) intermittently, if I flash the headlamps or switch them on, the radio cuts out for a couple of seconds. Sometimes it happens, sometimes it doesn't.

Haunted? :-)

Any ideas?

I would check all the connections from the battery to the fuses etc for tightness and corrosion (include the earth side). If you have a poor connection that has a little resistance in it then on low currents (ie driving) it will not drop much voltage, but on high currents such as starting it will drop significant voltage and the cars systems will think the battery has been disconnected.

If you remember your school physics Voltage = Resistance x Current

When currents get to hundreds of amps you don't need much of a bad connection to drop a large voltage.

Its also possible that your battery has a problem internally, you can get it tested at your local motor factors.

There are other possibilities but I would start here.

I was concerned the Battery might be a bit dodgy.

I only got it in December and I tried it with a Battery load tester when the problem first occurred and it was only a needle width away from being bad.

Took it back to Halfords who simply put a voltmeter on it and went "that's ok". When I complained that really wasn't a conclusive test they lost interest and told me i'd have to get it tested at a garage.

Wouldn't a garage only do the same thing I have?

Either way i'm still not convinced "The cars system will think the Battery has be disconnected" because as I already mentioned it's not only under load this occurs, sometimes I just get in the car and notice it's "dead" before I even turn the key (i've not been locking it in case you were wondering).

The problem happened again at the weekend and simply popping the bonnet got it working again. And set off the alarm. And immobilised it all for a while.... The git.

So..... i'll try swapping the battery for another I have knocking around to see if that does any good.

Anyone got any other suggestions?

[Davrav]

Apologies if this has already been suggested but have you checked ALL the earth straps. Sometimes they look OK but corrosion can build up between the terminal and the particular panel.

[Parts-King]

To change the 100 amp fuse you have to "lift up" the fuse box to get underneath it and undo the terminals for the fuse. I bet something has become loosened or the fuse holder was not tightened up properly, worth another look there for sure

Kingo