Nissan Forum banner

Radiator/Cooling fans - power, motor, or relay issue?

22535 Views 9 Replies 5 Participants Last post by  bigboost
Greetings all -

Just polling the masses to see if anyone has come across this issue before. My 93 SE (188k mi) was having some cooling issues recently. On highway speeds the temps were in the middle, but as soon as I hit traffic the temps would slowly rise. The other day the needle got near the "H" and boiled coolant over into the overfill tank because it was idling in the driveway. After some research I narrowed the issue down to either the thermostat or a radiator issue. Of course, no leaks were going on anywhere so I thought it might be the thermostat. The waterpump is about 2 years new. I changed the thermostat out yesterday (real PITA) - still the same issue. Of course, this time while hovering over the engine bay I noticed the fans never kicked on and a lightbulb instantly went off in my head. Oddly, if I shook the radiator around the driver's side fan would rotate - notice I didn't say "run", but rotate. Once I quit shaking it or tapping on the fan guard, the fan would simply quit rotating. It's almost as if either the fan motor is dying/dead or there is not enough voltage being supplied. The passenger side fan never turned at all. I checked and reseated both the relays and fan connectors. If I were to check voltages, would I simply touch the nodes of a voltmeter on the fan connector ends? Would the Haynes suggest a point to check voltages?

Given the above scenario, what would be your thoughts on what's causing the issue? A: bad fan motors, B: bad relays, C: bad connection or low voltage, D: OTHER

Thank you in advance for any suggestions you might have.
1 - 1 of 10 Posts
I just wanted to post a quick follow up for anyone experiencing this same issue.

To finalize troubleshooting, I swapped the A/C compressor and fan relays (they are the same). The A/C continued to work so I knew the relay was good. I checked the fuse box between the fender and battery and the fuse was good. The only component remaining was a faulty cable between the relax/fuse box and the actual fan connector itself. At that point I had decided replacing a 188k mi fan wouldn't be a terrible idea regardless. As soon as I replaced the fan assembly (no choice with an auto parts store - all they sell is a generic), the fan started up nicely. I'm only running with one fan right now, but no more overheat issues and my A/C all of a sudden feels much colder than ever. It makes me wonder how long I had a weak fan in the engine bay.

If anyone as a spare fan motor laying around, I'll need one for the passenger side fan. Thanks all for your help.
I have exactly the same problem with my 93 sentra. The deal is, though, that the cooling system was working just fine until i lost an engine seal and fried the crank on the old motor. I replaced the motor with another (used) one and used every single sensor, plug wiring harness, etc. and the engine started right up with the exception of the overheating problem. I removed the thermostat - it still runs in the half way point and now the fans have stopped working unless you turn on the air conditioner! I am looking for a way to wire around the auto function of the fans and just leave them on every time the key is turned on. The only pause I have with that is that maybe the fuel will continue to flow at "cool" settings. I simply cannot believe that both fans decided to go out at the same time due to age - and they DO run when the a/c is on. What the heck is going on with this system?
1 - 1 of 10 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.