Thermo fan plugs, spare connector & chassis bolt?

[Wolvesboy]

Hi All,
Having just removed the radiator:

I have found a second fan plug and have no idea whether this would make the second fan come on later or at the same time (I cannot test as just removed the radiator)! See pic...



Also in the pic is that separate strange blue plug into a black connector - any ideas?
I have a single thermo fan that comes on around 94 on the temp gauge. I was seriously thinking of adding a second manually switched fan as I feel the car is getting hot at 90. I feel the car is getting too hot above 90, especially when it is 30+ outside!

Finally, I found this rusty bolt hanging out 🤨The opposite side seems to fix the body to the chassis! I hope not too important as will replace but it has obviously been loose for a long time.
See pic taken from above...

[ukkid35]

The fan with thinner vanes which is on the RHS will only operate at higher temps, switching on/off independently

The blue connector is to the Ice detector

The loose bolt has saved you time, because when you need to do a body lift it often has to be cut out

[Jonbouy]

Looks like the rest of the bolt is still threaded in so it looks like it has snapped off, or someone has tried to remove it and sheared it

[Wolvesboy]

Thanks fellas

Ice detector! 😂

Ukkid - I only have one fan but two connectors. I’m assuming they will switch on at 92/96 from the ECU as seems to be the majority. Personally, with the outside temps here I think that is too hot. I’m certainly leaning towards a separate switched fan I can use in the daily commute traffic.

Bolt will be replaced but seemingly not a major issue then.

Now to clean up the coolant all over the bl***dy floor!

[CerbWill]

I assume you have no aircon then? You could try both fan connectors and see if they work. If you turn the ignition on and unplug the water temp sensor the ECU assumes a coolant temp of 95 degrees and puts both fans on.

If the 2nd connector doesn't work you're probably only missing the relay that plugs into the fuse board.

[gruffalo]

Regarding the second fan I was of the understanding it was only fitted to cars with air con.

I think the turn on points of the fans are 93 and 95 degrees they use the temp sensor down in the pipe to the rad that provides temp info to the ECU with in turn uses this to switch the fans.

[Wolvesboy]

All the pipe work for A/C is there but been disconnected by previous owner.
Still only one radiator fan though. I need another fan and I think I will rig up my own switch/ relay as there has to be voltage drop from the rear fuse box. Will be good to have one manually operated in case. I don’t fancy waiting until 96 before a fan comes on.
I have a brand new condenser to fit in front of the radiator but cannot see any distinct places to attach it to the radiator.

[Byker28i]

The aircon fan is thinner than the other. I've often thought about swapping it for a second thicker one, for those days when we're stuck in traffic in europe.

[Wolvesboy]

Just hit me - any possibility of fitting a different sensor with a lower temp rating switch?
Would then just perform the usual info to ECU and turn on the fan at a lower temp.etc.
Would potentially save a bit of messing around.

[Revvit]

Byker28i said:

The aircon fan is thinner than the other. I've often thought about swapping it for a second thicker one, for those days when we're stuck in traffic in europe.

Snap!!

[CerbWill]

Wolvesboy said:

Just hit me - any possibility of fitting a different sensor with a lower temp rating switch?
Would then just perform the usual info to ECU and turn on the fan at a lower temp.etc.
Would potentially save a bit of messing around.

Doesn't work like that. The temp sensor's resistance changes with temperature and that's how the ECU knows the temp. The ECU then switches the fans on at 92/95 degrees. Joolz sells a cooling chip, a replacement ECU chip with a standard map but lower temps for fan activation, somewhere around 88 IIRC.

Revvit said:

Snap!!

Revvit, that looks like a thicker rad with 2x thinner fans. Which radiator is it?

[Revvit]

Radtec radiator.

Fans are two of the higher duty Griffith fans I believe (after talking to TVR Parts).

This is the broken unit which was replaced.

[Wolvesboy]

I thought it was too simple!
I’ve decided to wire in a separate switched 2nd fan to see if it makes any cooling difference. Much simpler than messing about with the ECU etc.
New A/C condenser and drier fitted so when all done with the fan, I will get the system checked & gassed - fingers crossed.

[Byker28i]

Revvit said:

Radtec radiator.

Fans are two of the higher duty Griffith fans I believe (after talking to TVR Parts).

Interesting. I have the same radiator, but with original fans

[Revvit]

Normal TVR I guess, depends what’s in the parts bin on a Friday afternoon

[Wolvesboy]

I thought it was too simple!
I’ve decided to wire in a separate switched 2nd fan to see if it makes any cooling difference. Much simpler than messing about with the ECU etc.
New A/C condenser and drier fitted so when all done with the fan, I will get the system checked & gassed - fingers crossed.

[Byker28i]

Revvit said:

Normal TVR I guess, depends what’s in the parts bin on a Friday afternoon

No I swapped out my old rad after rebuilding it once for the radtec aluminum one. The large thick fan (nearside) is the fan usual one, the thinner one (offside) is the AC one as shown in the workshop manuals.

So you get one of these K0128: https://tvr-parts.com/tvr-parts/part-details/tvr-k...
and one of these K0072: https://tvr-parts.com/tvr-parts/part-details/tvr-k...

I've always wondered if there's a different airflow through each and if one is better performing than the other so having two the same would be better

[Revvit]

I meant my set-up

[CerbWill]

Byker28i said:

No I swapped out my old rad after rebuilding it once for the radtec aluminum one. The large thick fan (nearside) is the fan usual one, the thinner one (offside) is the AC one as shown in the workshop manuals.

So you get one of these K0128: https://tvr-parts.com/tvr-parts/part-details/tvr-k...
and one of these K0072: https://tvr-parts.com/tvr-parts/part-details/tvr-k...

I've always wondered if there's a different airflow through each and if one is better performing than the other so having two the same would be better

I did google the SPAL part numbers of the 2 fans a while ago and found theres a several hundred CFM difference between the two fans. I've seen photos of a Cerbera with 2x big fans fitted so I knew it could be done. After temps got worryingly hot on a european road trip (even with a brand new TVR parts brass radiator), climbing hills in the south of France I saw 103 degrees. Even though the car was fine, and should be as water at 1.5 bar won't boil until 115 Deg C, staring at the temp gauge did detract from the experience somewhat. I decided to fit a 2nd larger fan I got from a TVR scrap yard. Some cutting of the body is required to provide somewhere for the rad bottom hose to go with the bigger fan in place. The radiator sits in a U shape channel and the back of the U, behind the fan, needs lowering/removing to get it to fit without kinking the bottom hose.

I should probably get an aluminium radiator.

Edited by CerbWill on Tuesday 20th March 13:17

[FarmyardPants]

Revvit said:

Byker28i said:

The aircon fan is thinner than the other. I've often thought about swapping it for a second thicker one, for those days when we're stuck in traffic in europe.

Snap!!

You might have at least cleaned the engine bay before taking that photo!