Engine fan issues

[KarlBristol]

As some of you know my car recently discharged all of the electric from the battery into the car itself due to it not being earthed properly. This caused a small fire.

I've now got the car up and running again although the engine fan no longer works.

I got the car up to temperature today and the engine fan doesn't engage. This obviously also puts the warning light on the dash. Now electrics aren't my strong point, so can anyone put a step by step fault finding guide for me please?

I'm guessing its either a burnt/broken wire or potentially a damaged ecu. It all worked perfectly before the mini fire.

Any help would be much appreciated as I'm a little out of my depth where electrics are concerned

[Draven]

Check the Fuses.. I know it might be a simple one but check anyway..

check the wiring of the fan itself. you may have actually shorted the motor to the fan in which case it will need replacing.

[KarlBristol]

Thanks, I'll give that a go shortly.
My fuse box shows 4 fuses for various fans. I have no idea which one is relevant, any ideas?

[Draven]

Thanks, I'll give that a go shortly.
My fuse box shows 4 fuses for various fans. I have no idea which one is relevant, any ideas?

I'd just check them all..

[KarlBristol]

Lol, I'll have a look in a minute, knowing my luck it'll be more complex than that though!

Having spent over 30 hours in the past 3 days getting the car running again I am tempted to just put up a wanted add offering another user money to fix it, lol.

I refuse to use garages out of principle, lol

[Draven]

Lol, I'll have a look in a minute, knowing my luck it'll be more complex than that though!

Having spent over 30 hours in the past 3 days getting the car running again I am tempted to just put up a wanted add offering another user money to fix it, lol.

I refuse to use garages out of principle, lol

I only use one place for my car.. I'd not let any old monkey touch my 2


My prefered monkey is Luke @ Pacific Works.

[KarlBristol]

Lol, I'll have a look in a minute, knowing my luck it'll be more complex than that though!

Having spent over 30 hours in the past 3 days getting the car running again I am tempted to just put up a wanted add offering another user money to fix it, lol.

I refuse to use garages out of principle, lol

I only use one place for my car.. I'd not let any old monkey touch my 2


My prefered monkey is Luke @ Pacific Works.

Lol. Other than me, no one else has touched my car yet, I always get a bit worried thinking about driving it into a normal garage - doubt theyd even look in the back for the engine! Lol.

As much as ive heard good things about pacific works im a bit of a distance away as im im Bristol. Once the car is fully fixed again I might consider them for certain aspects of engine work

[KarlBristol]

The car went for a short drive today, and I can confirm that the engine fan definately is not working.

I've tried to take a video of start up today:



In case the link doesnt work, here is the direct link:

http://s1111.photobucket.com/albums/h48 ... 124216.mp4

The engine light and fan light are on when the car starts up, until the car gets revved...

No idea why! lol

The fan light comes on immediately after in the video as its just been for a drive...

[Draven]

Hmmm that is a difficult one.. the engine warning light would be a concern to me sounds like a pressure related thing.. i'd be a little concerned that your little fire may have melted something in the ECU as well

[KarlBristol]

The engine warning light goes out as soon as the car is started (thought that was normal?)

The fan and battery light go out when the car is revved after it is initially started

The fan light comes back on when the car gets up to temp

I think that the fire was primarily localised around the rear wheel/brake line

[Draven]

Ah right sorry I was looking at it wrong.. the battery light is a concern the fan light simply just comes on when the temp in the engine bay comes on when the temp in the engine bay goes over a certain temp and the fan isn't working correctly..

Do you have a volt meter??

I would unplug the fan and put a voltmeter into the plug..

If you get power.. then fan is dead

if you don't.. then it is a more serious issue.

[KarlBristol]

I presume that even if I get the fan working the battery light until revved is a whole different issue??

I will try and borrow a voltmeter. Guessing it could be the motor, ecu, wiring, fuses or the fan itself?

[Draven]

I presume that even if I get the fan working the battery light until revved is a whole different issue??

Yep possible alternator issue..

I will try and borrow a voltmeter. Guessing it could be the motor, ecu, wiring, fuses or the fan itself?

Yes you'll need to check all of them..



fault finding can be a b1tch.

[KarlBristol]

Uuuggghhh ... Spent way way too long working on the car this week to get it running again.

As such £100 cash to anyone who can sort out my engine fan and warning lights, (curing the fan fault should fix the warning light. If you can also sort out the wierd start up sequency with the battery light then brilliant)

Obviously if I need a new alternator I'll pick up the cost of that, lol.

[Lewis Jay]

Check the relay(s) in the engine bay that control the fan circuit(s).

[Harold]

Why not just take it along to an mr2 specialist?

[Peter Gidden]

The fan circuit is simple. I'll post up diagram later this evening.

[KarlBristol]

The fan circuit is simple. I'll post up diagram later this evening.

That'll be great thanks

[Peter Gidden]

I'm not convinced your fan issue is not a result of alternator circuit issues as the warning lights often come on together when there is an alternator/alternator wiring fault. If you were closer i'd collect that £100 within an hour of lifting your engine lid!

Assuming you're happy your charging circuit is not faulty in any way, here's the fan circuit:



All 3 wires at the top go 12+ve when ignition is switched on, so first check is the two fuses. Since the dash light illuminates, you know the 7.5A fuse is OK, so check you have a live on the relay side of the 20A fuse.

Check the fan itself by unplugging and applying 12V and earth to the terminals. Obviously it should work.

Check back with results.

[KarlBristol]

Thats great, thanks. Im probably not going to have a chance to have a look at it until next weekend so I will update then

Would a faulty alternator really stop the engine fan from working?

Another quick question ... Ive been looking at cars that have dual fans on the inside of the engine lids. Do these tend to be wired to a switch or wired into the original? Also are they a standard fit and where can I buy them from?