Cadillac Owners Forum banner
  • Hey everyone! Enter your ride HERE to be a part of September's Ride of the Month Challenge!
1 - 5 of 5 Posts

·
Registered
1991 Sedan Deville 4.9l 80k miles
Joined
·
91 Posts
Discussion Starter · #1 ·
I have read post after post, video after video, and more article than you could imagine. My Devile went from running nEar perfect to a no start no nothing condition! Battery is an AMG thats less than a year old, headlights don't dim when you turn the key, doesn't mater what gear you've selected you get the same! Nothing! Tested my relays by the glove box and they test fine. Relay clicks like it should when you turn the key to run

After that I can tell you its between the relay and the neural safety switch. I have pose on the yellow wire near the column when the key is switched to run and off like its supposed to. I do not have power entering or leaving the neutral safety switch. Any idea other than follow my yellow wire to the relay then back to the neutral safety switch? Yes I've checked all guides resumed and maxi.

On maybe a unrelated note periodically I lose the display for the fuel center and get a code for loss comm. Please help. I'm going to loss my job
 

·
Registered
1991 Sedan Deville 4.9l 80k miles
Joined
·
91 Posts
Discussion Starter · #3 ·
========================
FIRST - check for codes -

so - what systems/components affect the starter -

the SECURITY system -
resistor chip in the key -
the chip reader in the lock cylinder -

lock cylinder itself -

ignition switch -

neutral safety switch -

starter relay -

starter solenoid -

starter

main POSITIVE cable at the starter -

GROUND -

all the wiring between these components -

---------------------------

my GUESS would be the ignition switch
With a trouble light I was able to test and positively confirm 12.3v when the key is turn to run if that's the last position. Or the one you expect it to turn over.

Update:
I installed a new starter but same result as I expected. But, I can give the purple wire that leaves the neutral safety switch and goes to the s terminal on the starter. With the key turned on it turns over and starts. Still no power going into the neutral safety switch. I hear the relay click while turning the key to run and have switched them around as well as bench tested them all to verify they work. I do NOT know if its sending voltage as I cant find the wire. I thought maybe it was disconnected there behind the panel of relays is there anything fuse or other between the relay and neutral safety switch?
 

·
Registered
1991 Sedan Deville 4.9l 80k miles
Joined
·
91 Posts
Discussion Starter · #5 ·
I can here the relay click over when I attempt to start. Do I need to still jump the relay to test? What ground or where is the ground I need to test?
 

·
Registered
1991 Sedan Deville 4.9l 80k miles
Joined
·
91 Posts
Discussion Starter · #7 ·
Have you tried to start when putting shifter to neutral ?
When you go to a forward gear, does the electric door lock work and when going to neutral or park unlock ?
Did you check for any error codes and if any what were they ?

I have a 1993 sedan Deville FWD 4.L engine and had a no start issue
In short, it was the start/neutral switch was out of alignment and the shifter on top of it was too gunked up
I cleaned that whole area up, lubed the shift area and did the alignment as I show below and that cured the no start issue
It is also common for this switch to go bad and have to be replaced.

Also, when problem of no start the electric lock/unlock would randomly work or not, but after switch was re-aliened
the auto lock/unlock works

View attachment 621646
View attachment 621645
It shows codes e52, e58, e91 then
, ee91, and f31
 

·
Registered
1991 Sedan Deville 4.9l 80k miles
Joined
·
91 Posts
Discussion Starter · #15 · (Edited)
I decided to go back to the relay. Passenger side behind the glove box. They are in rows of 2 I seemed to have 6. My research shows that the left row second from the bottom is supposed to be the starter relay. I measure 12.2v when I turn the key to on. BTW I have pulled the relay from its socket for these tests. I first notice I cannot visually see any metal connection of any kind which should be pin 87. I also don't read voltage on any other pin when I turn the key all the way to run. I should see the 12v on 85 or 86 to activate the circuit while the key is turned all the way correct? Has anyone removed this junction box to see behind if?

Further more discovery lead to me removing all fuses and relays in (what is the name of TBE fuse / relay block behind the glove box on the passenger side?) And removing the 2 torx screws. I was able to pop the back cover from it. Now I can see the wires going in and where there connected. There is NOT a wire connection in the above mentioned spot. Odd thing is I can't see an extra unconnected wire. There is next to no slack to get a descent view. There has to be something in the hole were the 87 pin on the relay goes right?

Is there a wiring diagram for this block?
 
1 - 5 of 5 Posts
Top