Fan relay on Bravo and fan problems. FIXED!

[mountainmachine]

Hi guys have an HGT Bravo X reg and need to find out which of the relays controls the radiator fan. The ones that are situated just in front of the battery.

Reason is FIAT cant find the correct one on there system and neither can i on the EPC for the HGT. There are quite a few there and dont want to have to replace the others!

In the middle of fixing problem of fan not coming on so would overheat. Testsed and checked fuses, conected fan to battery and all ok. So relay, wiring or thermostat in radiator the problem i asume.

Testing of thermostat seems fiddly and time consuming especially as i dont know what it means by "and there will be zero resistance" i know what that'd mean in a physics term but when the gate is open surely there is infinite resistance and thus switch is off? (or on if its a reverse switch) And to pay a garage to test would cost more in labor than replacing the parts!

So as i cant test relay and replacing the cheapest and easiest items first! Then if no luck into the garage for a quote! Or i'll fit a fan on/off button on the dash or a temp controled switch from maplin on the radiator or something!

 

[mountainmachine]

Re: Fan relay on Bravo and fan problems.

Ok so went out in the rain and pulled out all the relays, gave the contacts a scrub with steel wool and a good clean, and moved them to an easier position. Have highlighted text which would be unclear in red etc. In the Brava 1.2sx only the red relay is there (as have one sitting) but it had a knackered fan so dont know if the relay is good.

Location in engine bay!



Relay 1


Relay 2



Relay 3

Relay 4



On reinstalling after cleaning gave engine a run then let heat up until red. No fan kicking in, no surprise. Then took it for a run to cool down. Help greatly appreciated as i need to do a long journey down to South England to get my timing belt done in a few wks. (from Scotland).

 

[Sven]

Re: Fan relay on Bravo and fan problems.

Here is all I have found - it should be the relays 123 and 123A.

But you must test them, not just clean.
Take some pics of them from ther pin side and I will try to tell you what to do - when testing you should hear a click if they work right.

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[mountainmachine]

Re: Fan relay on Bravo and fan problems.

Thanks i'll head back out after the rains stopped, never lets up this wk.

 

[mountainmachine]

Re: Fan relay on Bravo and fan problems.

Ok so taken pic of them all as i'm not able to identify which is which from the wiring diag, as cant quite make out the numbers.

relay 1


relay 2


relay 3


relay 4



I'd tried to test them with a multimeter the other day, but it was a borrowed one and had no internal power source. Have made up a set of test leads with crock clips, so i could test the fan operation.

 

[mountainmachine]

Re: Fan relay on Bravo and fan problems.

Sven i like your site by the way.

 

[Sven]

Re: Fan relay on Bravo and fan problems.

Cheers for the site

Ok, testing:
you will need a negativ and a 12V positive source (batt) and some wires.

relay 1 and relay 2 should click when you connect the negative on either 87 or 86 and positive on 85 or 30. You should hear a click if the work.

Relay4 is deffo 86 and 85 for the negative and positive.

Relay3 - a bit tricky, but as I know it should be the middle one and the far left one.

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[mountainmachine]

Re: Fan relay on Bravo and fan problems.

Results

Relay 1
Clicking on power through 86 and 85 but no clicking on anyother combination

Relay 2
Nothing.. no clicking on any combination

Relay 3
Nothing.. no clicking on any combination

Relay 4
Clickty click through 86 and 85

So should i replace just relays 2 and 3 or 1,2 and 3? Shop not open will tomorrow.

 

[Sven]

Re: Fan relay on Bravo and fan problems.

Replace 2 and 3 wheres no clicking.

The relay works this way: when it gets power it clicks, meaning it pulls a connection lever inside and makes a connection on the other pins.
So the ones that click are fine.

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[mountainmachine]

Re: Fan relay on Bravo and fan problems.

Thanks Sven i'll get the parts asap and let you know how she goes!

 

[mountainmachine]

Re: Fan relay on Bravo and fan problems.

Hi there was back into FIAt today to order the parts, as the incompotent fools couldnt find the fan relays on the system and i had to take in the parts themselves.

So took in the parts and they cant find out what they do. They dont know what the relays are for. Mmmm not good so i ask for replacment ones as they arent clicking. So relay 2 they can order £11.57, fine i say, (as already been round autofactors and they dont stock them) But relay 3 they dont have a clue what its for. "could be the fule injection, the air bags we just dont know" hmmm.

Ok i say cant you find out? Shuffle's off to see the auto electrician. Comes back "we'd need to run a diagnostic and go wireless with the ecu, and run an online diagnostic" (plug it in to the computer then) - right and how much will that cost? £47ish.

After i insist that i want to know what the relay does and have seen the wiring diag he consults the electrician again. Seemingly at the end of 99/00 they change the fan controll to an onboard ecu with a "possible" back up relay!

But the engine managment lights not on, "ahh well a fault like that it MIGHT not be, the car will kick into safe mode to allow you to get home" Surely rad fan control is major and would trigger the engine managment light as it could overheat the engine!

And then they say that relay 3 might not be a relay but a diode etc so may not switch etc. (But they stilll dont know what its for!)

So relay 2 will be a few days as special order! (no discount) But bring it in and they'll check it. I for £47 to tell me its a £10 relay?

I said after i've replaced the relay if its not working then i'll consider it. But not until they find out what relay 3 does etc.

Grrrrrrrrrrrrrrrr

 

[mountainmachine]

Re: Fan relay on Bravo and fan problems.

edited last msg's to clean up

 

[mountainmachine]

Re: Fan relay on Bravo and fan problems.

Ok so replaced relay 2 today and it hasnt seemed to make a difference. Will give it a few days. Did the same as before dorve then left to overheat, fan didnt come on so quick blast up the country roads to go from red to half way in under 2 mins!

 

[Owen]

Re: Fan relay on Bravo and fan problems.

Even if a relay clicks, it might still have a high contact resistance which would mean it would not work when subjected to high load currents such as fans etc. IF in doubt, test it by connecting a heavy load such as a headlamp bulb or fan etc through the contacts and energise the relay. if the load bulb lights, fan works etc, consider the relay fine.

In harsh damp conditions such as the engine bay, the contacts often oxidise and become high resistance. Most relays can be opened carefully and the contacts examined - bad corrosion will be evident. carefully scrape the contacts with a knife to try and fix it, or better still just get a new relay..

Owen.

 

[mountainmachine]

Re: Fan relay on Bravo and fan problems.

Ok havent got it fixed yet as been a bit busy, but need a temporary soloution until i can get it to a reputable fiat specialist.

I'm wanting to conect the fan to the battery with a switch in the car so i can turn it on and off. What do i need?

I know what connections are what etc on the fan as already had it wired directly with some old electrical cable. But want a better and safer soloution. Do i use speaker cable etc? Do i need to put in a fuse? What switch to use, as i know some can only handle a certain current etc.

Thanks

 

[mountainmachine]

Re: Fan relay on Bravo and fan problems.

Ok so been a while since i did anything about this as its not been overheating while driving and i've been taking the volvo when being likely to be stuck in traffic for ages.

But had a chance to take the thing that the fan etc is connected to after the fan motor, and i'm wondering what it is.

I think it's a temperature switch etc as where its located it would monitor the heat from the radiatior and possibly switch on when it gets to a certain temp etc.

Here's some pics:

 

[RR]

Re: Fan relay on Bravo and fan problems. WITH NEW INFO

I assume that you have shorted the fan to ensure that it's motor is still working? The wiring to teh relays often corrodes too - so take a good look at that too. Assuming that all is well, make sure it's well insulated with electricians tape.

Personally, I wouldn't bother wth FIAT anymore - bit the bullett and take it to a recommended auto-electrician.

 

[mountainmachine]

Re: Fan relay on Bravo and fan problems. WITH NEW INFO

Yup have shorted out the fan etc to check the motor works? Replaced 1 of the relays as FIAT cant find the other one! Havent checked the wiring yet.

Am loathed to take it in for a diagnostic.

 

[Sven]

Re: Fan relay on Bravo and fan problems. WITH NEW INFO

That looks like a fied reostat, a big resistor like the one you have on the in car ventilation fan

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[Anonymous]

Re: Fan relay on Bravo and fan problems. WITH NEW INFO

I remember Daz155HGT had this very same problem, but he's moved on to ALFA's.

Maybe wimmy can contact him for ya.