More powerful cooling fans?
Discussion
Hello guys, really need some advice on the more powerful cooling fans to which i’ve Fitted to my Trev? The fans really pull power into the engine, through the Radiator, pushing air from the engine bay, but I seem to blowing the fuse to which is fitted at 30amp, any solutions, everything will be considered?
What is the wattage rating on the fans? Watts = Volts x Amps. So if your fans are 120 watts each then simply divide the 120w by 12 volts = 10 amps each (20 amps total)
If your fans are rated at 180 watts then divide by 12 = 15 amps each. So both would be 30 amp. This will blow your fuse.
You need bigger wiring and a bigger fuse if you are at this level.
If your fans are rated at 180 watts then divide by 12 = 15 amps each. So both would be 30 amp. This will blow your fuse.
You need bigger wiring and a bigger fuse if you are at this level.
Simple solution would be to add a 70amp relay down near the rad with a supply direct from the back of the starter or the 100amp fuse. You could use a 40amp relay but it would also be running close to its limit.
70 amp relay £7 https://www.electricalcarservices.com/relay-12v-70...
Steve
70 amp relay £7 https://www.electricalcarservices.com/relay-12v-70...
Steve
You are really exceeding that capacity of any plug in fuse at that rating, so id switch to something you bolt down like this:
https://www.ebay.co.uk/itm/MIDI-STRIP-LINK-FUSE-HO...
Otherwise the contact points between the fuse and its carrier tend to overheat. If you are feeling technical its possible to run two fans in series to start with so they run at half speed (and half the current) and then switch to both at full speed / voltage if the temperature continues to rise, but it requres 2 temp switches and about 3 relays.
https://www.ebay.co.uk/itm/MIDI-STRIP-LINK-FUSE-HO...
Otherwise the contact points between the fuse and its carrier tend to overheat. If you are feeling technical its possible to run two fans in series to start with so they run at half speed (and half the current) and then switch to both at full speed / voltage if the temperature continues to rise, but it requres 2 temp switches and about 3 relays.
blitzracing said:
You are really exceeding that capacity of any plug in fuse at that rating, so id switch to something you bolt down like this:
https://www.ebay.co.uk/itm/MIDI-STRIP-LINK-FUSE-HO...
Otherwise the contact points between the fuse and its carrier tend to overheat. If you are feeling technical its possible to run two fans in series to start with so they run at half speed (and half the current) and then switch to both at full speed / voltage if the temperature continues to rise, but it requres 2 temp switches and about 3 relays.
Penelope will be along in a moment... https://www.ebay.co.uk/itm/MIDI-STRIP-LINK-FUSE-HO...
Otherwise the contact points between the fuse and its carrier tend to overheat. If you are feeling technical its possible to run two fans in series to start with so they run at half speed (and half the current) and then switch to both at full speed / voltage if the temperature continues to rise, but it requres 2 temp switches and about 3 relays.
You could wire them as in the below diagram or use one Otter switch/Temperature switch to control both relays, the important thing is not to use one fuse or one relay for two fans due to if/when a fault occurs both fans will stop working
Two fans = Two of everything....You know it makes sense
Two fans = Two of everything....You know it makes sense
Hello Guys,
I'm really grateful for all spending time to explain the issues to which I need to relate.
The fans are the same as fitted to the later car's, such as the Tuscan, Sagaris and T350, both of the fans are Spal, so no imitation products.
Electrics isn't my greatest area, so in relation to the Relays, can I just change the existing relay to the 70amp, then place an inline fuse such as detailed above?
Should I have two fuses, one for each or combine the both in one set up?
I'm really grateful for all spending time to explain the issues to which I need to relate.
The fans are the same as fitted to the later car's, such as the Tuscan, Sagaris and T350, both of the fans are Spal, so no imitation products.
Electrics isn't my greatest area, so in relation to the Relays, can I just change the existing relay to the 70amp, then place an inline fuse such as detailed above?
Should I have two fuses, one for each or combine the both in one set up?
Along with the rest of the wiring TVR specified I doubt your existing wiring is suited to the higher currents which is why I suggested fitting a relay close to the fans with increased wire gauge in that area.
Penny will be along soon to give you more info and the suggestion that 2 relays should be used giving a degree of redundancy.
Steve
Penny will be along soon to give you more info and the suggestion that 2 relays should be used giving a degree of redundancy.
Steve
Titanium46 said:
Hello Guys,
I'm really grateful for all spending time to explain the issues to which I need to relate.
The fans are the same as fitted to the later car's, such as the Tuscan, Sagaris and T350, both of the fans are Spal, so no imitation products.
Electrics isn't my greatest area, so in relation to the Relays, can I just change the existing relay to the 70amp, then place an inline fuse such as detailed above?
Should I have two fuses, one for each or combine the both in one set up?
Edited due to crossed posts with Steve_D who as already mentioned the problems that you will encounter with the TVR wiringI'm really grateful for all spending time to explain the issues to which I need to relate.
The fans are the same as fitted to the later car's, such as the Tuscan, Sagaris and T350, both of the fans are Spal, so no imitation products.
Electrics isn't my greatest area, so in relation to the Relays, can I just change the existing relay to the 70amp, then place an inline fuse such as detailed above?
Should I have two fuses, one for each or combine the both in one set up?
My below comments are now meaningless as Steve_D has answered your question
Unfortunately you can't uprate the relay without first checking if the TVR power supply to the original TVR fan relay is heavy enough to carry the current draw of 2 x Spal fans, if your TVR was originally wired to power 2 fans then there is a very good chance that the power supply to the TVR fan relay is heavy enough
If there is any doubt about the current carrying capacity of your original TVR cooling fan circuit.....by this I mean the power supply to the fan relay and the power supply/supplies out of the fan relay to each fan.....you will need to rewire the circuit as I have shown above
Edited by Penelope Stopit on Thursday 14th June 07:37
Using bolt-able fuse links will always be better than anything plug in due to the lower contact resistance, and one per fan is the way to go. Due to the difficulty of wiring relays in situ on the back of the radiator its worth doing as much as you can on the bench first- ie make up a plate to mount the relays and fuses and do the wiring loom so you have one big current feed wire to the two fuses, the two otter feed wires to the relay coils, the two fan outputs and an earth wire for the relays. Personally id solder to the relays directly, and its a far lower resistance joint than any spade / crimp connection, as its unlikely you will need to change the relays if you do the job properly in the first place. Try and keep the number of wiring connections / joints to a minimum.
Then bolt the assembly to a mounting point near the fans to keep all the wiring short. Id wire the fan earth wires directly to your local ground point. A good high current take of point for the fan relays is the rear of the alternator battery take off.
Otherwise if you want to stick to the TVR wiring- do a voltage check on the loom- measure the voltage on the back of the alternator battery connection (engine off) and compare it to the voltage on the back of the fans with them running, and see the voltage drop. Every volt you drop at say 40 amps is 40 watts heat dissipated so something will be getting hot if its not up to the job.
Then bolt the assembly to a mounting point near the fans to keep all the wiring short. Id wire the fan earth wires directly to your local ground point. A good high current take of point for the fan relays is the rear of the alternator battery take off.
Otherwise if you want to stick to the TVR wiring- do a voltage check on the loom- measure the voltage on the back of the alternator battery connection (engine off) and compare it to the voltage on the back of the fans with them running, and see the voltage drop. Every volt you drop at say 40 amps is 40 watts heat dissipated so something will be getting hot if its not up to the job.
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