I have owned this 88 IROC for 18 years. The coolant fans all of a sudden BOTH stopped working. I replaced the thermostat, coolant temp switch. When I went to examine the fan switch by the cylinder head on the passenger side the connector had broken off. I replaced it with a new pigtail. Still NO fans, either one. I know that one of them is operated by the coolant switch, and the other by the fan switch/ecm. The fusible link coming right off the positive battery cable is corroded some, but would this render BOTH fans inoperable? SHould I replace the fusible link or just repair the corroded wire? Also, I replaced the relay on teh firewall near the master cylinder. ANy help would be appreciated as she is a gorgeous car and I need her back on the road. Any help is SUPER appreciated.. Thanks ARA

 

i had a fusible link go bad on mine. had it replaced fans started workin again. i say replace that link

 

Thanks for the post. The fusible link goes right to the positive battery cable. Do you know if they sell just the link? Is there an actual fuse in it? Also, from memory I think that the relay on passenger side fender right at the battery was a fan relay as well. I think i had replaced it years and years ago. You know if that realy works the fans as well? I may replace it as well just for good measure. Thanks again for your post and help. ARA

 

ya try replacing that relay. it is a necessity for the fans to work. in addition, tug on the wires that plug into the relay connector, to make sure they are not loose, which can cause intermittent or no contact.

i had the main power wire plug for the relay pull completely out of the connector once. ordered new connector from www.tpiparts.net. great site, wonderful shipping, all wires match the stock colors for easy crimping and no mismatching. i also replaced the relay connectors on the firewall by the master cylinder with parts from that site.

id check all of them, see if any other connectors need to be replaced and order all at once.

as for the fusible link it was done at a shop but i believe you can just buy a new link

 

Also test the wire that goes to the fan switch - just ground the connector with the key on and the fan will work if that wire is good. Then you'll know if the switch wire and maybe switch is bad or not as well.

 

turn the airconditioning on. if the fans work your relay is fine. what coolant sensor did you replace? theres three, one by the 6th and 8th cylinders above the knock sensor. another in front of the block, and third on the driver side bank. what you run, TPI, TBI, CARB all american muscle

 

I am going to replace the fusible link that is located right next to the battery on the engine side of the battery as it has corroded quite badly as I stated. Noone carries it, as they don't know what size fuse it takes. ANyone know what size fuse it takes for me to get a new fusible link. Also, and importantly, does anyone know if that fusible link, if bad, would cause BOTH fans to not operate? ANy help is ALWAYS appreciated. THanks again. ARA

 

There is only one coolant sensor.

That is the fan switch, not a sensor. It controls the secondary fan. The A/C (granted the system is charged), will cause it to run as well.

That is the coolant sensor, for the ECM. It's located in the front of the TPI manifold base. All others are located on or around the thermostat housing. None are in the block.

That is the sending unit for the temperature gauge, not a sensor either.


@NJ2, I would start with a multimeter or, test light (meter is better) and check for voltage at the fan relays. It should be a heavy gauge (14) orange wire. This is is constant voltage from the battery (starter terminal where the battery connects).

If the voltage is good, your fuse link is alright. I would check the 'FAN' fuse (20A) under the dash as well. This supplies ignition controlled +12 to the coil side of the relay. If this fuse is blown, both the relays will not work.

The Helm manual doesn't give the amperage of the fuse link but, IIRC, I've seen 60A being it's rating.

I do remember seeing fuse links in the HELP section at Pep Boys. DorMan makes the HELP products. Most chain stores carry a Dorman catalog

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