Cooling fan for relay/fuze bay

[gluaisrothaii]

Looking at the fuse box and relay panel overheat issues- I am thinking about adding an avionic style cooling fan, using a flange bonded to the fuse box cover and SCAT tubing to get the air into the fuse box. This Lonestar fan is fairly quiet and consumes about 1/2 Amp. Interested in your thoughts.

Ken

[DMC-81]

Looking at the fuse box and relay panel overheat issues- I am thinking about adding an avionic style cooling fan, using a flange bonded to the fuse box cover and SCAT tubing to get the air into the fuse box. This Lonestar fan is fairly quiet and consumes about 1/2 Amp. Interested in your thoughts.

Ken

Yes, good thinking! I had the same thought because of the reasons you mentioned and for me, Florida's summer heat only makes matters worse. So, in July, I created an extra relay cover that has 3 mini computer fans that force cool air directly over the 3 main areas that generate heat (the fan fail/fan relay area, the fuse box area, and the RPM relay area). It uses a screened grate that exhausts the warm area out of the compartment. I figured that this design forces the air conditioned cabin air over these areas and the compartment in general. This way, I don't have to leave the compartment completely uncovered and using this device would give me added peace of mind while using the car.

The computer fans run on 24 volts so I made a converter box with an adjustable voltage converter inside and integrated on / off switch. I calculated that the 3 fans only generate .08 amps in total.
I finished the relay compartment cooler midway through August and have been testing it ever since. The operation is nearly silent. Total cost was less than $30. So far so good. Here are a couple pictures:

Relay Compartment cooler finished:


Fitted:


I'm interested in seeing your approach.

[CFI]

I created an extra relay cover that has 3 mini computer fans that force cool air directly over the 3 main areas that generate heat (the fan fail/fan relay area, the fuse box area, and the RPM relay area).

Two of those three areas you mentioned can be made cooler by using solid state relays. They’re pricey, but the temperature difference is dramatic. Changing the spade type connectors on the circuit breakers to o-ring type connectors made a difference too. The fuse box is a bigger challenge, but worth it. My fuse box was rebuilt 10 years ago and even after 11 hours of driving produces very little heat.

[DMC-81]

Two of those three areas you mentioned can be made cooler by using solid state relays. They’re pricey, but the temperature difference is dramatic. Changing the spade type connectors on the circuit breakers to o-ring type connectors made a difference too. The fuse box is a bigger challenge, but worth it. My fuse box was rebuilt 10 years ago and even after 11 hours of driving produces very little heat.

Thanks, and agreed. I have Dave McKeen's Solid State RPM relay, Fused Fan Fail unit (blue in the picture below), Solid State Fan Relay (brown), and Lambda Relay (yellow) as part of my compartment refresh. I highly recommend his parts. I replaced the fuse block and connectors and the Bosch relay update with DMC's kits. I also rebuilt and modded my Door Lock Module. So, this relay cooler is intended to keep my electrical investment as cool as possible.



RPM relay, oem design versus new McKeen design:


Modded and rebuilt DLM:


New Fuse block:



The relay compartment cooler is definitely an optional temperature management device, and shouldn't be used in place of a proper electrical rejuvenation.

[David T]

You can also leave the cover off of the fuseblock. It does get hot there, especially if you have bad connections (not just in the fuseblock) and electrical components failing and drawing more current then they are supposed to. The electrical system is not very robust with little extra margin for additional capacity so any overload will generate a lot of heat what with the wiring being undersized, the relays undersized and getting old, etc. Few people do anything proactive or any preventive maintenance when it comes to electrical systems. It only seems to get any attention when something goes wrong. Kudos to those that do take proactive action.

[gluaisrothaii]

Thanks, and agreed. I have Dave McKeen's Solid State RPM relay, Fused Fan Fail unit (blue in the picture below), Solid State Fan Relay (brown), and Lambda Relay (yellow) as part of my compartment refresh. I highly recommend his parts. I replaced the fuse block and connectors and the Bosch relay update with DMC's kits. I also rebuilt and modded my Door Lock Module. So, this relay cooler is intended to keep my electrical investment as cool as possible.



RPM relay, oem design versus new McKeen design:


Modded and rebuilt DLM:


New Fuse block:



The relay compartment cooler is definitely an optional temperature management device, and shouldn't be used in place of a proper electrical rejuvenation.

Great input. After I make some assessments of the state of my electrical equipment I'll start planning an overhaul in there. Fuse panel rebuild looks fairly straightforward if awkward from an access perspective.