WI PER RELAY
DESCRIPTION
A wiper relay is st andar d equipm ent on a ll models.
The wiper relay (or intermittent wipe relay) is
locat ed in a dedicated recept acle on the bot tom left of
the fuse block on the un derside of the st eering col-
umn (Fig. 33). The wiper relay is a conventional
In tern ational Stan da rds Organizat ion (ISO) micro
rela y. Relays conforming to the ISO specifications
have comm on physical dim ensions, cu rren t capaci-
ties, ter minal patt erns, and term inal functions. The
rela y is contain ed within a sm all, rect angula r,
molded pla st ic hou sing. The r elay is conn ected to all
of the requir ed inputs and ou tputs th rough the
instr umen t panel wir e harness conn ector by five
male spade-t ype t erminals th at extend from th e bot-
tom of th e relay ba se. The ISO designa tion for each
term inal is molded into the base a djacen t to the t er-
minal. The ISO terminal designa tions are as follows:
• 30 (Co mm on Fe e d) - This term inal is con-
nected to th e movable conta ct point of the relay.
• 85 (Coil Grou n d) - This ter minal is connected
to th e ground feed side of the rela y cont rol coil.
• 86 (Coil B atte ry) - This ter min al is connected
to th e bat tery feed side of the relay con trol coil.
• 87 (Norm ally Ope n) - Th is term ina l is con-
nected to the nor mally open fixed con tact point of the
relay.
• 87A (No rmally Close d) - This terminal is con-
nected to the n ormally closed fixed contact point of
the relay.
The wiper relay ca nnot be adjusted or repa ired. If
the r elay is dam aged or fa ulty, it mu st be repla ced.
OPERATION
The wiper relay (or inter mittent wipe relay) is an
electromechanica l switch th at uses a low cur rent
input from the inter mittent wipe logic cir cuitry
with in th e fu se block under neat h the steerin g colum n
to cont rol a high current out pu t t o the low speed
brush of the wiper motor. The movable common feed
contact point is held again st the fixed n ormally
closed contact point by spring pressu re. When the
rela y coil is energized, an electr omagnetic field is
pr odu ced by the coil windings. This electrom agn etic
field draws the movable relay con tact point a way
from the fixed norm ally closed cont act point, and
holds it against t he fixed nor mally open conta ct
point. Wh en the relay coil is de-energized, spring
pr essu re returns th e movable con tact point back
aga inst the fixed norm ally closed con tact point . A
resistor or diode is conn ected in para llel wit h the
rela y coil in the relay, a nd helps to dissipate volt age
spikes an d electromagn etic inter ference t hat can be
generat ed as the electromagn etic field of th e relay
coil colla pses.
The wiper relay ter minals a re connected to the
vehicle electrical syst em through a conn ector recept a-
cle in th e fu se block. The input s and ou tputs of th e
wiper relay in clude:
• Th e comm on feed ter min al (30) pr ovides an out-
pu t to the wiper motor low speed brush through the
wiper con trol circuitry of the multi-function swit ch on
the steering column . When the wiper relay is de-en-
ergized, th e com mon feed termina l is conn ected to
the input of the relay norm ally closed term ina l (87).
When th e wiper relay is ener gized, the com mon feed
term inal is connected to t he input of the rela y nor-
mally open term ina l (87A).
• Th e coil gr ound term inal (85) is connect ed t o
batt ery current thr ough a fused ignition switch out-
pu t circuit whenever th e ign ition switch is in t he On
position .
• Th e coil ba tter y terminal (86) is connected to th e
rela y con trol output of th e wiper, turn signals and
engine st art cont rol module within the fuse block
through th e wiper r elay control circuit. This elec-
tronic circuitry controls the grou nd pat h for th is cir-
cuit internally to ener gize or de-en ergize the wiper
rela y control coil based upon its program ming and
input s from th e wiper and washer contr ol cir cuit ry of
the multi-fu nction switch , th e wiper motor pa rk
switch , and the ignition switch.
• Th e n orma lly open ter min al (87) is connected to
the output of the wiper m otor par k switch th rough
the wiper mot or pa rk switch sen se circu it. This cir-
cuit can carry either battery cur rent (wipers are not
in park position ) or groun d (wipers ar e in park posi-
tion), depen ding upon the stat us of th e wiper par k
switch .
Fig. 33 Wiper Relay
1 - HOUSING
2 - TERMINAL (5)
3 - BASE
8R - 34 WIPERS/WASHERS VA
To Next Page
Loading...
