Cooling Fan Issue
#12
All my relays and fuses are in working order. I went ahead and checked every single one of them while I was in that box, as well as the ones in the side of the dash, LOL.
I can't get a read on the ECT without removing it, because the TB and the front of the intake manifold are in the way. The Haynes manual recommends testing it in a pot of hot water for the 3.8L engine, since it's so hard to get to while it's in the car. I figure that if I have to take it out, I'll replace it anyway since they're relatively cheap. It would take less time to replace it than to test it, LOL.
Before I do that, though, I'm going to look at all the wiring between the ECT and the PCM. I've had other wiring issues in this car before, so I'm crossing my fingers that this is the case here as well (really cheap fix). If there aren't any wiring anomalies, I'll replace the ECT and see what happens...
I can't get a read on the ECT without removing it, because the TB and the front of the intake manifold are in the way. The Haynes manual recommends testing it in a pot of hot water for the 3.8L engine, since it's so hard to get to while it's in the car. I figure that if I have to take it out, I'll replace it anyway since they're relatively cheap. It would take less time to replace it than to test it, LOL.
Before I do that, though, I'm going to look at all the wiring between the ECT and the PCM. I've had other wiring issues in this car before, so I'm crossing my fingers that this is the case here as well (really cheap fix). If there aren't any wiring anomalies, I'll replace the ECT and see what happens...
#13
So... I changed the ECT last night and that had no effect. The fans work normally with the A/C (low speed, or high if I set the A/C to max and run it for a while). The fans do not come on at all if the A/C is off (not even if the temp guage gets right up next to the redline). However, if I unplug the connector from the ECT, the fans stay on high speed at all times (I'm pretty sure they're supposed to do that when they don't get a signal from the ECT).
All the relays and fuses are still good, all the wiring seems to be working... Is it possible that my PCM needs to be reprogrammed or replaced? I can't think of anything else in that system...
All the relays and fuses are still good, all the wiring seems to be working... Is it possible that my PCM needs to be reprogrammed or replaced? I can't think of anything else in that system...
#14
I found this schematic online for fans:
http://shbox.com/1/fan_schematic_1995.jpg
I've got a '96, so it's the bottom diagram with three relays. This shows a fuse and a fusible link. Anybody know where that fusible link is located? I'm wondering if that fusible link is damaged...
http://shbox.com/1/fan_schematic_1995.jpg
I've got a '96, so it's the bottom diagram with three relays. This shows a fuse and a fusible link. Anybody know where that fusible link is located? I'm wondering if that fusible link is damaged...
#17
shows the fusable link on the red wire that goes from the relay to the battery. follow it and u should find the link. test the red wire at the relay and if theres power u have a good link.
#18
Hate to bring back a dead thread, but I'm STILL having this problem... Updates:
If I unplug the ECT, fans come on high. This leads me to believe that all wiring and fan motors are in working order.
If I turn on the A/C, fans come on low. If the A/C runs max for a long time, fans come on high. This again leads me to believe all wiring and fans are intact.
If A/C is off and ECT is connected, the fans NEVER come on, even when the temp is way too high.
I have replaced the ECT, the PCM, and all related relays and fuses, and still have the problem. For a long time now, I just turned on the A/C in order to get the fans on, but now my A/C clutch is bad so that's no longer an option. Help?
If I unplug the ECT, fans come on high. This leads me to believe that all wiring and fan motors are in working order.
If I turn on the A/C, fans come on low. If the A/C runs max for a long time, fans come on high. This again leads me to believe all wiring and fans are intact.
If A/C is off and ECT is connected, the fans NEVER come on, even when the temp is way too high.
I have replaced the ECT, the PCM, and all related relays and fuses, and still have the problem. For a long time now, I just turned on the A/C in order to get the fans on, but now my A/C clutch is bad so that's no longer an option. Help?
#19
Resolved
WOW... So, I was at AutoZone getting some A/C parts anyway, and on a whim I asked them if their OBD2 scanner could check engine temp. They took a look with me and found that the engine temp was WAY lower than the gauge reading (by about 40 degrees). When the gauge hit redline, the engine was still only at 205 F, so we let her run a little more and sure enough, the fans came on at the right temp based on the scanner. Time to replace that gauge, LOL!
#20
yah but which reading was right, ecm or gage. lol. may want to do some checking, maybe a mechanical gage or one of them temp guns, pretty kool things you can check for cylinder fire by testing exhaust manifold outlets, dont have to burn your hands lol.