Help needed to diagnose cooling fan issue

[rjben]

Hi all,

I'm having some problems with the 2nd cooling fan on my 500 Griff - it does not come on when the 1st fan does. The 2nd fan works when connected to the 1st fan output. The 2nd fan output shows no voltage across it when I short the otter switch.

The fans look this this:



I have the following fuse box in my car. The fan fuse on far left is 40A and intact. The horn fuse (3rd from right) is 20A. Removing the 40A stops the 1st fan working. Removing the 20A stops the horn working.



There are also a bunch of relays next to the ECU - Are these anything to do with it?





Finally there is also this fused connector (7.5A) - no idea what this is for?



So is it possible from these pics that I have a 2 stage fan / fan upgrade of any kind? Also, the top left relay on the fusebox is for the fans (according to the Bible). Does this have independent control of both fans or does the fact that the 1st fan works prove the relay is working as expected?

Any hints would be much appreciated!

Thanks,

Rob

[WazzaL]

I had a problem recently when my 2nd fan refused to stop working... Was on the London tunnels run when it happened...

I found one of the relays had gone. I changed the fan relays over and the problem switched to the other side.

So popped to local breakers yard and yanked out a few redundant relays. Wacked one in, and away we went with no probs...


Editted to say:
Looks like you have a different fuse/relay set up to mine! - Hope this helps still. - Don't you just love TVR electricals.

Edited by WazzaL on Wednesday 23 January 13:20

[rjben]

so you have 2 fan relays? I appear to only have 1? Am I mistaken?

Cheers

Rob

[WazzaL]

Do you have the bible? Have a look to see if you can match your to one in there.

There were many different incarnations of the boxes over the years.

[rjben]

Yes, mine matches the bottom diagram on p242. This indicates there is only 1 fan relay unfortunately.

Cheers,

Rob

[so called]

The relay may use seperate contacts internally to switch the two fans so that it halves the current across the contacts.
So it could still be a relay issue and worth going to the breakers.
If the relay is OK and your not getting a supply to the second fan then it would point to a broken wire or that the second fan supply runs through some additional control such as a thermostat ???
Change the relay first.
Good luck.

[David Beer]

Early cars had one relay and 40 amp fuse, the relays shown are not for fans, but the 7.5 fuse is an odd one, not enough for a fan though !

[rs mexico]

Yes there was a single relay version and a twin relay version for the cooling systm,AS per TVR sometimes its not quite right the first time .There was also different size fans fitted aswell ie, shift more air .The block in your hand with the grey/brown/blue/yellow wires in the back is for the heater motor (is it a griff).First have you a water leak in the footwell,possible water in relay board.At the top left of the board there should be some foam blocking a hole up also could have a grommet in.Pull it out and there should be a connector block for the front loom.Short out fan switch and check if there is a 12v feed to the 2 large pink wires.if so the problem is at the front of the car if not its relay board down.Easy job a single bolt uunder it in your picture,then check for loose blocks ,again check for 12v feed on the large pink wires.ON some cars the fan circuit had burnt out in the board itself.

[Pasco]

rs mexico said:

Yes there was a single relay version and a twin relay version for the cooling systm,AS per TVR sometimes its not quite right the first time .There was also different size fans fitted aswell ie, shift more air .The block in your hand with the grey/brown/blue/yellow wires in the back is for the heater motor (is it a griff).First have you a water leak in the footwell,possible water in relay board.At the top left of the board there should be some foam blocking a hole up also could have a grommet in.Pull it out and there should be a connector block for the front loom.Short out fan switch and check if there is a 12v feed to the 2 large pink wires.if so the problem is at the front of the car if not its relay board down.Easy job a single bolt uunder it in your picture,then check for loose blocks ,again check for 12v feed on the large pink wires.ON some cars the fan circuit had burnt out in the board itself.

Here speaks a man who know's I hope things are well for you buddy

[rs mexico]

I have a mass of paper work on TVR electrics going back to the wedges .Just waiting to pass them on to someone worthy .

[Pasco]

rs mexico said:

I have a mass of paper work on TVR electrics going back to the wedges .Just waiting to pass them on to someone worthy .

What about the car club then the information can be kept and protected and used for the masses rather than for profit if you see what i mean

[rs mexico]

Wouldn,t sell it anyway or let it go to a garage, but would pass it on under the right circumstances.

[Pasco]

rs mexico said:

Wouldn,t sell it anyway or let it go to a garage, but would pass it on under the right circumstances.

Fella i was not referring to you making a profit but people interested in your information would no doubt want to hence my suggestion regarding the car club

I seem to recall they are trying to gather information to secure the long term future of our cars and indeed the cars you spent so much time and effort on.

Incidentally i have nothing to do with the TVRCC other than being a member for the last eight years or so

It's your choice i guess

[rs mexico]

They can always email me on my profile site.

[Pasco]

rs mexico said:

They can always email me on my profile site.

V8 Grif lives up your way i have e-mailed him

[LordGrover]

rs mexico said:

I have a mass of paper work on TVR electrics going back to the wedges .Just waiting to pass them on to someone worthy .

I don't suppose it's possible to ask BB to make it available through thegriffithpages?

Edited by LordGrover on Thursday 24th January 16:56

[rjben]

oi what about me?!

Thanks for suggestion re relay.

Cheers

Rob

[V8 GRF]

rs mexico said:

They can always email me on my profile site.

YHM