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So I’ve been searching and scouring these forums for help but haven’t found what I’m looking for.
The issue: 1998 rx7 is overheating. And has something to do with the fans.
what I’ve done:
1) installed fluidyne radiator
2) installed pettit metal AST
3) replaced AST cap
3) installed cooler mishimoto thermostat
4) jumped TFA and GND to verify relays 2&4 are working along with fan motors and the fuse.
5) I have used a lisle funnel and burped the system multiple times to try and get the air out. I’m using 70/30 distilled water/coolant + a bottle of water wetter.
Here’s what’s happening:
when I drive the car on the freeway temps are stable. It’ll over heat idling or driving through town. Initially I figured this has something to do with the fans, and I was able to remedy the issue a bit by turning on the A/C.
I noticed on a few test drives that when I’d check the fans they weren’t running. My A/C switch is turning on the fans sometimes but not all the time. I thought this was due to a faulty alternator causing voltage issues, (I was having strange electrical symptoms like my DEFI gauges going dim) I replaced the alternator and started testing my fans. The first night, the fans would come on sometimes but not everytime, at one point the fans started acting strange and the speeds would vary up and down. I chalked this up to a dying battery and put the car on a tender over night and my battery is reading good voltage now.
I can hear my fan relays clicking. And when I jump TFA to GND the fan comes on. So I ruled out relays 2 and 4 the fuse and the fan motors. (The fans came on on every test I did this way)
I need to test the thermoswitch, but that still shouldn’t have anything to do with the fans not coming on from the A/C switch. The fans also do not come at the right temp, the car has seen up to 110c before turning it off and the fans didn’t come on.
I read my headlights can act as an extra fan input but the lights don’t turn on the fan or affect fan speed if they are on from my A/C switch.
im including pics of my grounds, and as you can see the bolts are pretty rusty and I’m pulling the bumper tomorrow to test continuity on them.
this issue has me pulling my hair out trying to figure out what to do.
does anyone have any ideas of what to check next or what this could potentially be?
Are you running a power FC? If so you could at least check if the fan operational temps have been modified. You could always run a switch to manually to on and off the fans while you continue to troubleshoot if this is your only means of transportation.
Are you running a power FC? If so you could at least check if the fan operational temps have been modified. You could always run a switch to manually to on and off the fans while you continue to troubleshoot if this is your only means of transportation.
im not. I purchased one but have yet to install it.
the car is pretty much stock aside from a cat back exhaust and high flow cat midpipe.
and I’ve got 4 other cars including a daily, the rx7 is just my garage queen lol so I’m okay taking time to find and fix the issue.
Before you get too deep into the electrical troubleshooting, one suggestion is to have a look under the front fender wells to see if your tires chewed thru the plastic fender liner and damaged any of the front wiring harness that lies beneath the liner. If your FD was ever lowered or is running on tire/wheel sizes other than stock spec, that kind of damage is a possibility and could result in a bunch of electrical gremlins. Since the fan wiring runs thru that harness, a quick visual inspection wouldn't hurt.
Before you get too deep into the electrical troubleshooting, one suggestion is to have a look under the front fender wells to see if your tires chewed thru the plastic fender liner and damaged any of the front wiring harness that lies beneath the liner. If your FD was ever lowered or is running on tire/wheel sizes other than stock spec, that kind of damage is a possibility and could result in a bunch of electrical gremlins. Since the fan wiring runs thru that harness, a quick visual inspection wouldn't hurt.
the car came with stock wheels and tires but that’s a good suggestion. I’ll check that today. Thank you!
Stock cars run REALLY hot. Read my fan thread, 110c on a stock car is not out of the ordinary.
But hopefully you can get those temps down.
Do you have the belly pan on the car?
Does the AC actually work on the car? If the AC doesn't work turning the AC on may not bump a fan speed.
Your car doesn't have the fan thermoswitch if it's a 98. 2 speeds are all controlled by the ECU. I don't know what temps the stock ECU kicks them on at on the later cars.
If you have a PFC and can get or borrow a Datalogit, spend the 30 minutes and install it. Since it's a JDM car you don't have to remove the 4 wires, it's full plug and play. Then you can drop fan speed 1 and 2 down to 85 deg. C or whatever you like.
Stock cars run REALLY hot. Read my fan thread, 110c on a stock car is not out of the ordinary.
But hopefully you can get those temps down.
Do you have the belly pan on the car?
Does the AC actually work on the car? If the AC doesn't work turning the AC on may not bump a fan speed.
Your car doesn't have the fan thermoswitch if it's a 98. 2 speeds are all controlled by the ECU. I don't know what temps the stock ECU kicks them on at on the later cars.
If you have a PFC and can get or borrow a Datalogit, spend the 30 minutes and install it. Since it's a JDM car you don't have to remove the 4 wires, it's full plug and play. Then you can drop fan speed 1 and 2 down to 85 deg. C or whatever you like.
Dale
yeah I read a bunch of your threads haha, super helpful.
belly pan is on the car and tightened up appropriately.
a/c works amazing.
I just learned about the thermoswitch after ordering the 85c one from Pettit lol. (Now I need to return it)
I have a PFC I got from crooober but I haven’t installed it yet and I don’t have access to datalogit, my hopes were the combo of the new rad+cooler thermostat would help keep it cooler.
I also checked the fan grounds in the picture.
1 is completely bad, the other only reads continuity on one part of the metal bracket, the rest is dead.
so right now my focus is fixing these grounds first and seeing if that makes the situation better.
08-11-23, 12:24 AM
