ignition Amplifier help!!!

[achris]

Re: ignition Amplifier help!!!

Should be able to...

 

[riverman223]

Re: ignition Amplifier help!!!

http://forums.iboats.com/newreply.p...iboats.com/newreply.php?do=postreply&t=625090

 

[riverman223]

Re: ignition Amplifier help!!!





here is some pics of what i got.
i have my shift interruptor wired as you would in a TB IV
can ya tell if it came from a 350 alpha or brovo by the wire coming out of icm

 

[achris]

Re: ignition Amplifier help!!!

That looks like a later model TB-V box. Any chance you could take the box off it's bracket and have a look on the back. It may have some number on it that will identify it....

 

[riverman223]

Re: ignition Amplifier help!!!

i went out and took it off the bracket the only numbers on it looked like quality control label

says 5.u/
25b

 

[achris]

Re: ignition Amplifier help!!!

Bummer!!!

Looks like we/you might have to do some timing graphs of your own. Put the module in base timing mode (ground the Pur/Wht wire), fire up the engine and record the advance every 100 revs (starting from about 600)... Then plot it on a piece of paper... See what it looks like. You have to do it in Base mode so the TB5 features are disabled and you get ONLY the primary timing curve....

Chris......

 

[riverman223]

thunderbolt troubles

thunderbolt troubles

If you replace your 2nd gen. TD IV with newer style TD modual (icm)do you normally have to change anything besides some wiring to make it run the same?

 

[riverman223]

Re: ignition Amplifier help!!!

Yeah whatever it came off from it was built into the harness. What I am saying is that the plugs that go into the ICM were part of the motor harness I had to cut them off the harness should have spent the $400 and ordered the one per my ser.#
I'm about to just throw in a delco system. I'm going to have to get a timing light and a tach.
Just frustrated not much time left here in Michigan for boating need to get her going!

 

[achris]

Re: ignition Amplifier help!!!

As good as the Delco system is (and significantly cheaper), it's not even remotely as good as the TB-IV...

There's been a few threads lately from people who've done the conversion, and had some pretty serious problems as a result. There's quite a bit of wiring changes to be made too. The promotion of the Delco is that it is a 'drop-in replacement' for the Merc TB-IV system... It's not, not even close. All the existing Merc wiring for the ignition and distributor has to come out, the shift interrupt switch has to be completely rewired.... Yeah, 'drop-in replacement', NOT!

I'd look for a replacement TB-IV module on ebay....

(have a look at this one... Mercruiser Ingnition Module | eBay) But doing a search actually came up with quite a few...

Chris.........

 

[Fun Times]

Re: ignition Amplifier help!!!

i went out and took it off the bracket the only numbers on it looked like quality control label View attachment 209862View attachment 209863

says 5.u/
25b

Sure that u is not an 0 ? As in 5.0?:fish2:

It might be difficult now but it may have been worth taking a chance with just getting an used original ICU.
There are a few online to be had,

390-7804A3
Mercruiser Ignition Amplifier Assembly 7804A 3 15248T02 | eBay

Mercruiser Ignition Amplifier Assembly 7804A 3, 15248T02

The white with black wire should be to tied into the shift interrupt switch following the service manual. Do you have it connected up that way?

 

[achris]

Re: thunderbolt troubles

Re: thunderbolt troubles

What engine? Year, serial number....

Also, define what you mean by 'newer style TD modual (icm)'... There is no newer style for the TB-IV beyond the second generation.

Chris......

 

[Fun Times]

Re: thunderbolt troubles

Re: thunderbolt troubles

What engine? Year, serial number....

Also, define what you mean by 'newer style TD modual (icm)'... There is no newer style for the TB-IV beyond the second generation.

Chris......

Chris, This thread looks to be just a continuance of "ignition-amplifier-help" thread. I think Riverman is just trying to get some additional ideas from some of the other forum members that have switched from TB 4 to 5 with success or failure stories is all. The other thread is pretty long to read through now.

http://forums.iboats.com/mercruiser...outdrives/ignition-amplifier-help-625090.html

Good luck Riverman.

 

[achris]

Re: thunderbolt troubles

Re: thunderbolt troubles

Chris, This thread looks to be just a continuance of "ignition-amplifier-help" thread....

:thumb: Noticed the username AFTER I posted.. :facepalm:

Hope it works out...

 

[riverman223]

Re: ignition Amplifier help!!!

No I do not but I am going to try that today thanks!

 

[riverman223]

Re: ignition Amplifier help!!!

Just so expensive for something so old that could brake tommarow,

 

[achris]

Re: ignition Amplifier help!!!

Just so expensive for something so old that could break tomorrow.

It's not just Mercury. Most manufacturers don't want you to repair old equipment (some manufacturers consider anything out of the warranty period as 'old')... They want you to scrap the old stuff and buy new. They 'encourage' us to do this by pricing the spare parts for that 'old' equipment so high as to make it unfeasible to repair. The other thing they will do is not make spares available....

Good example. Philips, TV makers. A few years ago (many be about 15 by now :facepalm announced in Australia that they no longer carried ANY spares for the TVs... If the TV failed within the warranty period, a new TV was GIVEN to the client. If the TV failed after warranty, SELL the client a new TV.... As result, I do not have ANY Philips products in my house (I like to be able to fix things)....

Ok... Back on topic, a bit... As a result of your problem, and having seen a few like it, I am in the process of designing and fabricating a replacement for the TB-IV module. The circuitry isn't that complex, but it will take me a little time to do all the testing. Not soon enough for you, I'm sorry, but hopefully they will be able to help a few people in the future...

Chris.....

BTW. I'm with you... much rather repair than replace... total waste of good resources....