mcm95403

Of course, only on a day that it's almost 100 degrees out do my cooling fans decide to quit running. The car got so hot in the couple of miles from the freeway to my carport that it was stalling. It was almost at 260 when I pulled in. I hosed down the radiator, got it started to circulate water and kept hosing it down to get the temps under control.

If anyone can point me to the correct location for the fan relays, the switch in the head (can't remember which side is the temp sender and which is the fan switch/coolant temp sensor), the part number for the lower-temp fan switch (the generic one, not the $40 Hypertech one), and any other helpful info, I'd really appreciate it.

rodj

Stock there is no mech switch in the head ;
both fans are controlled by the computer which gets it's engine temp signal from the CTS at front of engine
Temp sender on '91 is between # 6 and 8 plugs
IIRC ; fan relays on '90+ cars are on drv side of radiator shroud ( by headlight)


One I use
http://www.racerpartswholesale.com/p...n_Accessories2

mcm95403

Thanks Rod! I replaced the CTS when I did the intake a couple of months ago. I'll check the relays & fuses in the morning.

mcm95403

Well, chock this one up to another funky intermittent problem. I disconnected the battery, reconnected it and tried it - fans both came on with the A/C on.

mcm95403

I spoke too soon. Looks like the fans only run if the A/C is on.

cuengineer

Well, at least you know the motors and relays work as they should with A/C on. Now the question is whether there is a broken wire or switch or other control issue. Good luck in tracking down the gremlin.

mcm95403

OK, so now I'm even more confused. The connector on my radiator fan switch is "oval" with two prongs, yet all the fan switches I find are single pin with a round connector. The Hypertech fan switch comes with a pigtail that looks like it has the wrong connector too.

What gives?

I also looked at the MAM fan switch info and their instructions don't say much of anything about 91's but do have some detail on the earlier cars.

mcm95403

I've found that the passenger side fan doesn't come on at all, but if I swap the plugs on the relays it does. Looks like one of the two relays is bad. Off to Autozone to pick one up. At least it's only $13.

mcm95403

I was wrong. I thought the passenger side fan came on but it didn't. Tomorrow I'm going to run 12v directly to it and see if it spins. If not, it's time for a fan motor. Only $43 for that, so still not bad.