NB cooling fans

ianoz · Postby **ianoz** » Sun Dec 31, 2017 2:39 am

basic question - but on an NB which radiator fan is the engine fan and which the AC fan? In the midst of stripping out unwanted bits, so can't start the car to check...

From what I've found it appears that the fan on the passenger side is the normal engine fan - even though that's adjacent to the AC fan relay - and the fan furthest from the AC fan relay is actually the AC fan... :roll:

sigh... I think I've cut the wrong wires... :oops:

Lokiel · Postby **Lokiel** » Sun Dec 31, 2017 12:17 pm

You are correct.

See https://drive.google.com/drive/folders/0B3YbfB30DxW0bEdwS0xSNGVXMzA Cooling Fans.pdf Page 15

These are MSM/SE documents but are mostly relevent to all NBs - it's worth looking at them before you do any electrical work.

ianoz · Postby **ianoz** » Sun Dec 31, 2017 5:10 pm

thanks Lokiel. That’s a good site to have

My own fault for assuming and not checking - but can’t imagine what was in the engineers mind when he designed that layout.. put the AC fan and clutch relays as far forward as possible on the opposite side so the power lines all need to run from fuse box, across behind the dash, all the way to the front, u-turn, back across behind the dash, and then all the way forward again and across the engine... 4 m of wire instead of 0.4... :roll:

manga_blue · Postby **manga_blue** » Sun Dec 31, 2017 6:43 pm

The car was originally designed the USA as a LHD. Mazda in Japan did the conversion to RHD, presumably on a shoestring budget. There are lots of el cheapo conversion shortcuts on NAs. Have a look at the clutch hydraulic line for a good example. You've probably just stumbled across another one.

Lokiel · Postby **Lokiel** » Mon Jan 01, 2018 11:13 am

I should also have mentioned that MSM/SEs have different fans to other NBs, MSM/SEs have 2-stage fans, a low and high speed, regular NBs only have a single-speed fans so for specifics on the regular NB fan electrics, see https://www.miataforumz.com/how-40/mazda-miata-wiring-diagrams-1990-2002-a-497/ too.

ianoz · Postby **ianoz** » Mon Jan 01, 2018 4:42 pm

The car was originally designed the USA as a LHD. Mazda in Japan did the conversion to RHD, presumably on a shoestring budget.

that actually explains a lot.. always assumed being Japanese it was designed RHD!

Thanks again Lokiel for the links. Tucked away for reference

You wouldn't know a doc showing which wiring will cause the standard ECU to bring up an error light if chopped? I'm expecting to put resistors across the wiring when removing airbags, seatbelt pretensioners, egr valve, charcoal canister valve, & standard seats - are there any others to watch for? (stripping out for track only but standard engine/ecu)

SKYHI · Postby **SKYHI** » Tue Apr 02, 2019 2:17 pm

So just to clarify, the fan on the drivers side of our NB/SEs is the AC fan, and the fan on the passengers side is the cooling fan?

Now that I've removed the AC equipment in the engine bay of my SE, I'm considering either removing the AC fan as well, or wiring it up to a switch on the dash, so that I can run it for a few minutes in the pits after each time attack session.

Lokiel · Postby **Lokiel** » Tue Apr 02, 2019 8:29 pm

SKYHI wrote:So just to clarify, the fan on the drivers side of our NB/SEs is the AC fan, and the fan on the passengers side is the cooling fan?

Now that I've removed the AC equipment in the engine bay of my SE, I'm considering either removing the AC fan as well, or wiring it up to a switch on the dash, so that I can run it for a few minutes in the pits after each time attack session.

Yep and yep (ie. good idea to keep as an extra fan for the pits).

SKYHI · Postby **SKYHI** » Wed Apr 03, 2019 11:58 am

Lokiel wrote:
SKYHI wrote:So just to clarify, the fan on the drivers side of our NB/SEs is the AC fan, and the fan on the passengers side is the cooling fan?

Now that I've removed the AC equipment in the engine bay of my SE, I'm considering either removing the AC fan as well, or wiring it up to a switch on the dash, so that I can run it for a few minutes in the pits after each time attack session.

Yep and yep (ie. good idea to keep as an extra fan for the pits).

Awesome, thanks. Now to just work out the wiring. I usually don't play well with electrics