1986 vette not cranking
11-08-2010, 08:13 PM
#1
5th Gear
Thread Starter
Member Since: Nov 2010
Posts: 5
Likes: 0
Received 0 Likes
on
0 Posts
1986 vette not cranking
I have a 1986 vette with auto trans and new battery. The car will not crank and no sound from solenoid. Dash lights come on with ign. key at run. I did some troubleshooting from my shop manual and found the dark green wire from the starter enable relay to the vats decoder module. When I jumper this wire to ground then turn key to start, it starts with no problem. Does this mean that I have a bad relay or vats or starter solenoid?
11-08-2010, 08:31 PM
#2
Le Mans Master
Member Since: Aug 2000
Location: Sydney Australia
Posts: 8,837
Likes: 0
Received 30 Likes
on
29 Posts
May be bad connection at module / may be faulty module = $$$
Quick fix ; bypass the enable relay.( join the two heavy wires @ relay together )
You will still have security because VATS takes out the injectors as well
11-11-2010, 09:56 PM
#3
5th Gear
Thread Starter
Member Since: Nov 2010
Posts: 5
Likes: 0
Received 0 Likes
on
0 Posts
trying to understand fix.
If I put the 2 yellow wires together, how will it fix the problem? My manual shows signal from key ohms goes to vata decoder module first. Then if ohms from key is correct then a signal goes to relay to allow power to solenoid. If there is no power to relay then how will the signal go to the starter?
11-12-2010, 07:37 AM
#4
Race Director
Member Since: Jan 2003
Location: Summerland B.C. Canada
Posts: 19,667
Likes: 0
Received 36 Likes
on
32 Posts
The power is already at the relay when ignition is in crank position. The decoder module only supplies ground to primary side, to close the contacts and transfer power from ignition switch to starter solenoid.
11-12-2010, 04:15 PM
#5
5th Gear
Thread Starter
Member Since: Nov 2010
Posts: 5
Likes: 0
Received 0 Likes
on
0 Posts
correct me if i'm wrong , it's not the 2 yellow wires that go into the relay but the yellow wire that goes in the relay and the green and white wire that goes out. When I jumper these 2 wires it cranks and starts. so by doing this it does not matter that my vats module is not grounding?
11-12-2010, 08:45 PM
#6
Le Mans Master
Member Since: Aug 2000
Location: Sydney Australia
Posts: 8,837
Likes: 0
Received 30 Likes
on
29 Posts
There is no feedback to show the relay is working ( or even there )
The starter enable relay is only a cutout for security; not needed as part of the starting system.
The fact it starts with the relay bypassed shows the other part of VATS is functional.
If VATS module was totally faulty you would have no fire because VATS takes out the injectors as well
