What is gone on is the the car will heat up and the fan will come on, after it cools the fan shuts off. GREAT Car will heat up again and fan will never come back on at all. ANY IDEAS also could you tell me were things are at in the fan circuit?

 

Engine (lg4, TPI,..) and temperatures would help.

Single fan, dual. Title says 'fan' (singular') and 'relays' (suggesting dual fans). Though, I'm fairly positive dual fans weren't until '87.

Single fan realy is on the firewall over the bulkhead, next to the brake booster.

TPI is ECM controlled (220°F). Carb'd, fan switch (238°).

 

It is a single fan 305 TPI. The temp comes up to 220 fan kicks on temp goes down fan kicks off temp will then come back up and will keep going all the way to red line and the fan will not ever come back on. Figured it is a sensor or relay but I did not know were to start looking.

 

check your fan switch (passenger side on lower side of motor), CTS sensor (front of manifold below throttle body...theres two sensors there, its the one on the left)...Fan relay (driver side firewall)

 

Thanks for the info I will check this out when I get time and let you all know what I found.