[Mk2] [Turbo] dash warning lights-battery, alternator and unknown

[mattymr2]

these lights have come up on my dash and i dont know what the one to the right of the battery and the one to the left of the seatbelt warning lights mean?

car seems ok but im worried. they came on itermitantly but now are on all the time.

thanks guys

[mattymr2]

the one to the left of the seatbelt warning light is a Engine Compartment Cooling Fan Warning Light.

[mattymr2]

well the battery went flat on me whilst driving this afternoon and conked out just as i got to the end of my drive. had to push it the rest of the way.


is my alternator knackered maybe?

[toxo]

Yeah, those 5 warning lights coming on all at once is a sign that your charging system is broken. It could be battery, alternator, or wiring. It's usually alternator though!

The light you're not sure on (left) is the CAT temp warning light. You'd only ever see it come on under normal operation when your CAT is on fire

[mattymr2]

thanks toxo. god knows wot im gonna do i cant afford a new alternator.

[toxo]

It might not be alternator, there are checks to do.

Make sure your battery is OK, it might be suffering a bit now that you've run it flat.

It might be that your charging circuit is not working. The dashboard christmas tree effect happens when the nominal voltage in the car drops too low (lower than 11v maybe). You can check this out by pulling the 3 pin plug off the alternator (you'll need to be under the car for this) and making sure you have battery voltage at all 3 pins with the ignition on.

If that's the case then it could be your alternator. Don't get too upset though as I am due to do a guide to refurbing alternators soon

[mattymr2]

its a new heavy duty battery last year. ar'll get under and have a look tomorrow. thanks again

[mattymr2]

problem solved!


finally felt well enough to get on with the car today.

basically the rubber cover for the alternator connection with the nut had split and was letting water in. the wiring had started to corrode and stop conducting.

a quick clean up and some wd40 and no more dash lights and a working altenator.

just need a replacement cover now.

[Si_Crewe]

What's the betting the actual cause of this was all the salt on the roads over winter?

Am I the only one who notices a definite increase in leccy faults during icy weather?

Wonder why we're the only country in europe who still grits the roads with rocksalt?

[Flip1977]

It might not be alternator, there are checks to do.

Make sure your battery is OK, it might be suffering a bit now that you've run it flat.

It might be that your charging circuit is not working. The dashboard christmas tree effect happens when the nominal voltage in the car drops too low (lower than 11v maybe). You can check this out by pulling the 3 pin plug off the alternator (you'll need to be under the car for this) and making sure you have battery voltage at all 3 pins with the ignition on.

If that's the case then it could be your alternator. Don't get too upset though as I am due to do a guide to refurbing alternators soon

My apologies for pulling this thread back from the dead, but hopefully you can help, after a search, this seems the closest to my problem. My better half has a UK MK2 Mr2, which flattened its battery. I jump-pack started it, and we had a nice healthy 14.5v at the battery, so I thought the alternator was fine, just a duff battery. Stuck a spare one in it (with enough charge to start it) for the morning run, with the view to getting a new battery today. That battery was flat by morning, but I jumpstarted the car, and attempted to drive anyway, thinking the alternatator would charge up the battery fully and it was probably not that lively to begin with.

The car battery gauge wouldn't get in the "positive" end of the scale, and we had these five christmas lights. On tick over the lights would be ok, but a touch of throttle and on they'd come. Power steering would stop working, and the battery gauge would slowly drop until there was nothing there. In the end I limped home (only about 0.5 mile) running off the battery pack.

Tonight, I bought a new battery. Fitted this, fired up no problem, but now my dashboard lights were still on? Volt meter showed some 18v at the battery this time! I unplugged the 3 pin plug, and I have 11.6v, 12.4v and 12.4v on the three pins with the ignition on, and the main connection seems fine and dandy. After a few tests I found that running the car with the headlights on seems to knock the voltage down enough so that the guage drops to a more healthy level, and all the warning lights go off. Voltage in is a lot healthier and the battery gauge sits around the middle of the positive range. Turn the lights off, volts go up, warning lights come on. I could replicate this with the fan, and windscreen wipers on, etc, anything with a decent draw would sort everything out.

So, is there a voltage regulator somewhere that could be at fault? Do I need a new alternator? Is there anything else I can test? Do I just need to go for a decent drive with the lights on and let everything (hopefully) settle down? (Maybe a nice drive will dry out any wet things and charge up any flat things and all will magically be well?) Hopefully I can sort this out with you guy's help - this purchase isn't turning out to be that wise at the moment (

[toxo]

Regulator is in the alternator but it's in the removeable section at the top and can be purchased seperately!

[Flip1977]

Excellent - that's an encouraging start! Does it sound like the regulator is the bit at fault then? Don't suppose you'd know how easy they are to replace or where to get them from do you?

Found a couple of posts talking about pulling the ECU-IG fuse too and it all being connected to the engine bay cooling fan? As its cold out, is there an easy way I can disable that to see if its the culprit? I've checked the ecu-IG fuse and its ok

[Peter Gidden]

Just to summarise - using a proper voltmeter (not the dash instrument), you're seeing 18V with the engine idling?

[Flip1977]

Just to summarise - using a proper voltmeter (not the dash instrument), you're seeing 18V with the engine idling?

Yep, that's right, and if I switch on the headlights I get that down to around 16 or so. With wipers and fan, etc going too, I saw a (what I would consider) more reasonable 14v odd.

[mattymr2]

Have any modifications or work being carried out on the car since the problems started?

Have you checked the connections to the alternator for corrosion?

Are all the fuses ok?

[Peter Gidden]

Just to summarise - using a proper voltmeter (not the dash instrument), you're seeing 18V with the engine idling?

Yep, that's right, and if I switch on the headlights I get that down to around 16 or so. With wipers and fan, etc going too, I saw a (what I would consider) more reasonable 14v odd.

So foget messing with engine bay fans etc. As previously suggested, sounds like the regulator inside the alternator.

[Flip1977]

Excellent, thank you!

Just to add, here is the story from today - hopefully we still reach the same conclusion...

Started the car this morning (after removing, inspecting and replacing the ECU-IG fuse last night) and all seemed fine. Voltage at the battery was around 13v and dashboard warning lights were out as they should be. Sat like that for 2 or three minutes so I thought I'd take it to work (30 miles, mostly 60mph motorway).

For the first 20 miles it was fine, charging needle sat about halfway up the gauge on tick over, and toward the top of the gauge at 2,000rpm and up. Didn't have any extra electrical stuff going on. Then I had a bit of sustained 70mph which held the revs that bit higher, and up went the volts, on came the dash lights. Turning on the headlights and the rear demister got the needle back down to about three quarters of the way up the gauge and the warning lights turned off. Stopped for petrol, started back up and it was all fine with no need for headlights for the last 2 miles of journey. Checked in my car park and at idle the volts were at 12.4v and after a bit of sustained revving they were up around the 13.5v mark, again, no warning lights.

So, does this still sound like it can only be a regulator on the way out/defective? Next question, how do you go about changing this? Is it a alternator out problem? Anyone know where to get a new regulator from?

[toxo]

Alternator out, unscrew the (probably not very these days) shiny metal cover on the top et voila! One regulator. You can get it from Toyota, or the same regulator is used in some Honda alternators as well so you can get them off eBay but quality may vary. You could replace the brushes for the alternator while you're in there to extend its life.

It will cost you nearly as much as a reconditioned alternator though!

[Flip1977]

Thanks toxo, The alternator actually looks in fairly good nick, I'm thinking some water must have got in there and fried the regulator - its been pretty wet down my way these past couple of days. Seen a post or two about making the alternator a little lid to keep the rain out from the engine cover vent holes?

So, if there really isn't much difference in price I may as well get a recon alt... at least then you know its good. Online price seems to be about £85-95 - is that about right, or does anyone have any gem's up their sleeves?

[toxo]

Remember there are 5 or 6 different alternators used across the MK2 MR2 range, you need to get the right one. It'll have a sticky label on it with the part number on.

My experience with reconditioned alternators has not been great, but I did eventually get one that worked properly.