Volt drop with Dyna fitted

[sprint]

Have an A4 on which I have fitted a Dyna electronic ignition.

Has started OK but at low speeds and coming off a closed throttle it has always snatched and spluttered, but it did this with the points fitted and was hoping that fitting the Dyna would cure it, but has not.

However, over the last couple of days it has become more or less impossible to ride as under any load it would snatch, misfire and judder. Removed the tank and was checking the wiring and voltages and found that the voltage to the std coils was only about 8.5V, engine not running. Went to fuse and found one side very hot, enough to melt part of the plastic holder. Cleaned the contacts and it was now about 11V at the fuse and 10.0V at the coils. However, when I disconnect the feed from the Dyna it jumps up to 12.5V.

Clearly the 8.5V was a problem caused by a high resistance joint on the fuse holder and bike starts OK, have not had time to ride it since sorting out the fuse but am assuming that the latest problem is/was due to low voltage, but is a volt drop of around 2/2.5V normal with the Dyna fitted without the engine running? Do you get a similar drop with points?

[wilsonsjw11]

Sprint,
I would go for the Wired George mod and also fit Dyna coils if you have not done already to guarantee 12volts plus to the Dyna S and coils.
Also a good look round all the connectors etc.
Regards
Steve

[HowieD]

Sprint,
I was having the same sort of trouble when i was building my Mk7 wiring loom the other week. I found the Dyna-S is pulling 5A with the ignition turned on and it was also pulling my battery voltage right down too. Turned out my not used much Lithium Battery was shot !

I found on the www a very good guide to testing the Dyna-S and also how to check for voltage drop across connections which help lots with troubleshooting.

PM me an e-mail address and I'll send them to you.

How can i post a PDF into Technical help ?? so everyone can have a copy ??

regards
Howie

[KeithZ1R]

email it to me Howie I will upload it

[sprint]

Sprint,
I was having the same sort of trouble when i was building my Mk7 wiring loom the other week. I found the Dyna-S is pulling 5A with the ignition turned on and it was also pulling my battery voltage right down too. Turned out my not used much Lithium Battery was shot !

I found on the www a very good guide to testing the Dyna-S and also how to check for voltage drop across connections which help lots with troubleshooting.

PM me an e-mail address and I'll send them to you.

How can i post a PDF into Technical help ?? so everyone can have a copy ??

regards
Howie

Thanks HowieD

PM sent

[Al]

You need to test the voltage with the magnet pointing away from the pickup modules as well.
See below.






AL

[KeithZ1R]

The 2 files Howie has are now in the " downloads " section under "Technical Bulletins"