HotQuat4k

I am having a problem with all of the seat heaters in my 87 5000CS TQ. I have a list of possible problems, but which is most likely to go first:

-switch
-relay
-fuse
-heating element in seat

This is a great site! thanks for all the help lately!

MiB@100-2.3NF-91

Both seats or just one?
If both, could be anything, fuse, relay, switch.
If driver's seat heater doesn't work,
I think IMHO, you should start from checking heating element.

5000CDQturbo

hope this helps ya .... it took a while to write up, thank god I save a
copy.
cheers
David

Basic Information
Test procedure below

Plug connector A female
---X(1) ** ---X(2) ---X (3)
---X(4) ** ---X(5) ---X (6)

this connector goes under the carpet and leads to the auxiliary relay
panel
X denotes a metal ( female type ) electrical connector
* denotes empty ( void ) space .... helps for orientation

wires coloured as follows

Driver side
1 brown
2 blk / white
3 blk/yell
4 brown/blue ( jumper to 5 )
5 brown/blue
6 brown/black

Passenger side
1 brown
2 green/blk
3 blk/red
4 brown/blue ( jumper to 5 )
5 brown/blue
6 brown/white


Plug connector B male
---X(1) ** ---X(2) ---X (3)
---X(4) ** ---X(5) ---X (6)
x= metal spade ( male type) electronic connector
** denotes empty ( void ) space .... helps for orientation

colours as follows
driver and passenger sides both the same

1 brown/blk ( back heater element) if you connect 1& 4 you should get
continuity if not
fix element
2 brown/blue ( *** heater element ) if you connect 2& 6 you should get
continuity if not fix
element
3 brown/blk
4 brown ( back heater element ) if you connect 1& 4 you should get
continuity if not fix
element
5 blk/white
6 blk/yellow ( *** heater element ) if you connect 2& 6 you should get
continuity if not fix
element

test procedure

1 turn on ignition
2 flip on seat heater switch ( leave this on for the entire test )
STEP 1
the plug need to be connected for step 1. If the plugs are not connected
this test procedure
will not work. after Step 1 is completed the connectors can be pulled
apart for all of the
remaining tests.

The first step is to be sure that there is power going to the seat. Find
a good known ground,
I use the cigarette lighter ( the top area ) Now you are grounded hook
the positive side of
your meter into Connection A (3) If you have power ( light ) then skip
to step Three .

Step 2
if you don't have power then remove the panel under the steering wheel
and locate the
auxiliary relay panel ( ratchet and socket need to undo the panel ) .
Locate the appropriate
relay ,#13 & 14 (pre 91) or 14 and 18 (91 + )
Remove the relays and look at the bottom of the relay, near the prongs
there will be a "H"
and on anther prong there will be a "15" by it ( along with markings for
all the other prongs
) Locate where the prongs of the H and 15 plug in the relay Panel. Test
the H slot ( in the
relay panel ) with a circuit tester to be sure there it has power. If
there is no power check
the fuse, if fuse okay locate break in the wiring between the fuse and
the relay panel.
If H slot has power then test the continuity of the wire between the
relay and the seat. To
do this put the multimeter in the lowest resistance ( ohms) rangepit one
end into the 15 slot
and place the other end in the connector A (3) . you should get a small
resistance between
the two, if you get no reaction from the multimeter, trace the wire back
and repair the
break. If you obtain a resistance test the function of the switch. To do
this, use the circuit
tester and connect it to ground and the 86 slot in the relay panel. Also
check the p slot for
power.... this should barley light in the first two positions and then
it shouldn't light. If
power is not attained at both slots then repair/replace the switch or
wiring between. If
power is attained at both slots then swap the relay with the other one
and return to step on
( or see if the seat gets hot with the new relay ) 4-5 mins

step 3
this step requires checking the continuity of the heating elements. To
do this use connector
B. Use a lowest res. setting on the multimeter an connect 2 & 6 Again
you should end up
with a very small res. If not then the Butt, *** heating element has a
break in it. see my
article on this. dm
if you obtain a small resistance then go to step 4

step 4 ( two options
connect the circuit tester to a known voltage source and connect to
connector a(1) If there
is no power ( light ) then trace the wiring and repair break. If you get
power you have me
a mistake somewhere, go back to step one and follow the procedure again
( or heated
seats work )

OR

set multimeter to the lowest res setting and check for continuity. To do
this place one lead
on a known ground and the other lead to connection A (1) Again you
should get a small
res. If no res is returned then trace wiring and repair the break. If
there is a little res then
you have made a mistake somewhere, go back to step one and follow the
procedure again
( or your heated seat works )

regards
David