No start

Tiny
JOHNRMASK
  • MEMBER
  • 1999 PONTIAC FIREBIRD
  • 3.8L
  • V6
  • 2WD
  • MANUAL
  • 206,000 MILES
I am getting power from my ignition switch to starter relay but no power from the relay to the starter. I have checked everything I could think of and it all comes down to no power going to the starter. When I check the wires with a tester light there is nothing going down the starter wire or from the relay itself. I need help please.
Sunday, November 25th, 2018 AT 3:42 PM

1 Reply

Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 108,179 POSTS
Hi and thanks for using 2CarPros.

When you say there is no power to the starter, I will assume you are referring to the smaller solenoid wire.

With that in mind, I need you to first check and confirm the 50A maxi fuse (ignition) and the 15 amp starter mini fuse in the under hood fuse box are both good. If the fuses are good, confirm that power is going through both.

Next, make sure the clutch pedal switch has power both in and out of the switch. It will be a purple wire with a white tracer power in to switch, and a dark green wire taking power to the starter relay.

At the relay, C4 should always be hot. Confirm that. Next, pin B4 should receive power when the key is in the start position, so you will need a helper for that.

If you have power to both C4 and B4 but nothing from B6, either the relay is bad or the body control module starter relay controller has failed.

At that point, I would try a different relay. If you have already done that and are certain all connections are good, I suspect a problem in the body control module. The body control module basically grounds one side of the relay coil.

The only other thing I can think of is if the vehicle has a factory anti theft system. If that system is activated, the BCM will not allow the starter to work.

I attached a schematic for you to look at. It is the entire starting system. I had to break it into two pics because of size.

Also, here is a link that shows how to check a relay, just in case you need it:

https://www.2carpros.com/articles/how-to-check-an-electrical-relay-and-wiring-control-circuit

I hope something here helps. Before doing anything, make sure the mini-fuse I mentioned is not blown and power is going through the clutch switch.

Take care and let me know what you find. I am interested in knowing.

Joe
Was this
answer
helpful?
Yes
No
+1
Sunday, November 25th, 2018 AT 7:33 PM

Please login or register to post a reply.

Sponsored links