No Sparks

[Clarida]

When testing the voltage from the ECM it shows only 11.2 Volts when cranking its drops to 8.7. The engine cranks but does not start. any Ideas. I did switch to a used model. still getting less then 12 volts just around 11.6 volts until I crank the engine then it drops to 8.7 volts on the red/ white wire to the Distributor. any idea

 

[76SeaRay]

What is the voltage going into the ECM before and during starting, that is, what is its power supply level?

 

[achris]

When testing the voltage from the ECM it shows only 11.2 Volts when cranking its drops to 8.7. The engine cranks but does not start. any Ideas. I did switch to a used model. still getting less then 12 volts just around 11.6 volts until I crank the engine then it drops to 8.7 volts on the red/ white wire to the Distributor. any idea

And we are working on....... ?????
Model, year, serial number.

Thank you...

 

[Clarida]

What is the voltage going into the ECM before and during starting, that is, what is its power supply level?

4.3 Mercruiser V6 Alpha Serial Number 0L371963 Before is 11.6 V and when starting 8.6

 

[Clarida]

It has been a Head scratcher. I did change the module same results. I was wondering where I am losing Voltage

 

[chevymaher]

Are you testing at the battery?

 

[achris]

... ECM ...

4.3 Mercruiser V6 Alpha Serial Number 0L371963 Before is 11.6 V and when starting 8.6

That model (1998 4.3L) doesn't have an ECM, it has a 'Thunderbolt V, ignition module'.

Here's a link to an 'explainer' on those ignition systems.
Follow the faultfinding tree at the end of the document?

How Mercruiser Thunderbolt ignition systems work.

Mercruiser Thunderbolt ignition systems. Mercruiser introduced the Thunderbolt IV onto their engines in 1982, alongside the introduction of the 1-R drives. The TB-IV system was used until the introduction of TB-V mid-way through 1996. Thunderbolt V was an improvement on an already exceptionally...

forums.iboats.com

 

[Bondo]

4.3 Mercruiser V6 Alpha Serial Number 0L371963 Before is 11.6 V and when starting 8.6

Ayuh,...... Yer battery is dead,.....

 

[Scott Danforth]

a full battery is about 12.7 volts
your battery is below 12, which means its dead

electronics need over 9 volts to operate, your at 8.6

test your battery, charge as needed, replace as needed clean your battery cable connections as needed.

 

[Scott Danforth]

I am testing at the red/white wire from the ICM

how about charging the battery

 

[nola mike]

You literally now have 3 threads going (with a conflict on what problem you're having) where you are either ignoring or not reporting the results of all of the troubleshooting steps being given to you

 

[Scott Danforth]

and you have two forum member names

 

[Clarida]

I am not sure how to use this forum

 

[Clarida]

I do have a good battery and the engine is on block as I have install all new parts to a new block. I am checking the harness to see if there is any damage. I will report after I check it.