Chrysler 105HP 1978 Pre-Amp (trigger)

[Moon Rock]

I have chrysler 105hp 1978 on my boat and there is not spark. Checked the coil and CD and its okay. While testing the pre-amp, it fluctuates between 7V to 12V while turning the flywheel or inserting paper between the LED and receiver. Does this pre-amp bad? Should it be fluctuating between 0-12V instead?
If so does any one has a used pre-amp for sale?
Thanks,
Mike

 

[Frank Acampora]

Re: Chrysler 105HP 1978 Pre-Amp (trigger)

According to the manual, there is no way to actually test the pre-amp on these electronic systems. You simply must replace it with a known good one. However, it is possible to replace it with points but that requires a rotor with a four lobe cam.

I have been lucky and have not needed to replace one so I have never tested the open and blanked voltages.

 

[Moon Rock]

Re: Chrysler 105HP 1978 Pre-Amp (trigger)

Thanks Frank!
Yeah I remember the Seloc book says that. I just ordered the pre-amp. Lets see when it arrives here in Calgary. Will put it in and see how it goes.