COOLANT FAN RELAY FAILURES BURNED OR STICKING CONTACTS

"Please discard previous bulletin 85-1-1 with above title due to incorrect section number. "

We have heard of some repeated coolant fan relay failures. When a coolant fan relay has failed due to burned or sticking contacts, the circuit should be checked for poor connections, excessive fan motor currents, or a chattering engine coolant temperature switch.

Fan motor continuous operating currents should not exceed 20 amps on low speed or 35 amps on high speed.

The coolant fan engine temperature switch can be checked with a test light. The light should turn on solid when the switch closes. If the light flickers, the switch must be replaced. Both the high speed and low speed portions of the temperature switch should be checked.

A chattering engine temperature switch causes poor relay operation and eventual failure of the relay contacts due to excessive arcing.

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.