Thunderbolt IV woes

[Biggyniner]

Got to love boats!

Fixed a cracked head only to have a no spark (no power at coil) issue, after putting her back together.

Triple checked all wiring connectors in the engine compartment. Cranking but no fire.,

Tested kill switch - ok, tested ignition switch ok. No 12V at the red/white wire coming from ignition module. All of this was of course with ignition on and the bloody 'engine out' alarm blaring.... I'm assuming this means I got a bad ignition module? Any tips or confirmation??

Thanks!

 

[achris]

No 12v at the coil + is a feed problem... Find out why you have no power on the purple wires...

And the alarm is 'low engine oil pressure', not engine out...

 

[Biggyniner]

Ok... Any links to a Thunderbolt 4 ignition wiring schematic?

 

[achris]

Ok... Any links to a Thunderbolt 4 ignition wiring schematic?

http://forums.iboats.com/forum/engi...-mercruiser-thunderbolt-ignition-systems-work

 

[Biggyniner]

http://forums.iboats.com/forum/engi...-mercruiser-thunderbolt-ignition-systems-work

THIS IS AMAZING AND SO SIMPLY LAID OUT

Thanks Chris, you are an incredible asset to this forum

 

[Biggyniner]

Double checking my ignition switch. If my gauges work, and the starter works, likely the switch is ok, correct?

 

[achris]

Yes, but make sure the key keeps power on the ON terminal while cranking. I've seen keys switches fail like that...

 

[Biggyniner]

I yanked the **** out of the harness and now its running....

But now its overheating, pretty sure the impeller is toast. I accidentally ran it once up until it almost overheated because I thought the water was on but it wasn't, I think it bit the dust, time to order the impeller kit and watch your video on how to do it again...

 

[Biggyniner]

One more question, how important is it to use the slinger seal install tool when doing the impeller. I've read a lot of people saying they don't bother using it??

 

[achris]

People who don't bother with it are asking for an overheat... Tool comes with an impeller kit. Click on 'My Vidoes' at the bottom of my signature for a video of a gen ii pump service...

 

[nola mike]

I don't recall using or seeing this tool.. . Is this for gen 1's as well?

 

[achris]

I don't recall using or seeing this tool.. . Is this for gen 1's as well?

No. Completely different water pump.... I also have a video on Alpha one pump service too

Chris....

 

[nola mike]

No. Completely different water pump.... I also have a video on Alpha one pump service too

Chris....

Good, done it at least half dozen times, hate to think I've been doing it wrong. I didn't see whether the op had a gen 1 or 2...

 

[Biggyniner]

Right, the reason I was asking was because I found this kit for an amazing price:

However it apparently does not come with the slinger install tool.

 

[Biggyniner]

Disregard I found a Sierra kit that was a bit more but still way cheaper than the Quicksilver kit. It appears to have the tool