Possible side effect with Petronix ignition

[Deleted member 8987]

That's because it isn't there.
If it was, it would take out things like radios, GPS units....you know, the things you'd have to have Schottky diodes in place to shunt it to ground....and since ground isn't really ground, the transients would be floating around the car body.....just think as you shut it off and a valet attendant starts to open your door for you and you pitch him into the pool with transient spikes.....

It's okay.
None of us knows for sure until we get some empirical data back from the crime scene.

 

[Keoke]

That's because it isn't there

You are correct the Healey is far to simple to exhibit this kind of aproblem but a a Mustang or later more complicated vehicle certainly might.

OH!! you know why the vallet opens the car door for you?-So he gets the shock and not you--Keoke-- :laugh:

 

[Deleted member 8987]

I drove the Jag up to a birthday dinner at the Casino at Snoqualmie last year.....drove round the front door to let folks out, then park.
ALL the Valets started towards me until they saw it was RHD, and they all backed up.

When we go to diner in Seattle in thw 1950 Ford, the Valets come up, I explain 6V, manual choke, manual COLUMN shift transmission with NO synchomesh in low, and they tell me where to park it in their valet lot.

Just convert your car to RHD and you can stop the valets in their tracks!

 

[Keoke]

Just convert your car to RHD and you can stop the valets in their tracks! [/quote]

I don't have to do no convertin to RHD. What you think my Daimler 250 V8 Saloon straight out of England be!!!----Keoke :laugh:

 

[Deleted member 8987]

So, how do the varmints (err..valets) deal with that?

 

[Keoke]

So, how do the varmints (err..valets) deal with that?

I do not let them get any closer than 10'. Just tell me where you want me to park it.--Keoke-- :laugh:

 

[RAC68]

Hi Mike,

Without rehashing my previous post, I did some looking and verified that a sneak circuit is present within the Healey that will carry residual power from an alternator/generator to the Petronix. The combination of alternator residual power generation, sneak circuit, and low power requirements of your new Petronix ignition module could be the contributing factors to your engine run-on.

When the ignition is turned off, power is cut to multiple components including ignition and fuel pump. As the engine cycles down, residual power is still being created and can be carried through a “sneak circuit” to the coil and Petronix. If a reverse alternator current is present, it will pass through the charge indicator light circuit and on to the #2 terminal of the ignition switch. From the ignition switch, the current will flow back to the coil and on to the Pertronix. Since the Pertronix requires less power than points, it will fire and produce the engine’s ongoing operation. However, as the sneak circuit is a very inefficient path, it will fall below the requirements of the Petronix ignition in short order and the engine will stop.

By installing a diode in the charge indicator light circuit, you will cap the back-flow of alternator current and eliminate engine run-on. An MG owner suggested you use a Schottky Barrier Rectifier (40V A3) 1N5822 (from Active Components) that has a forward voltage drop of 0.2V rather than the 0.8V of a standard diode. This lower voltage drop will preserve the function of the alternator sense line.

All the best,

Ray (64BJ8P1)

 

[Keoke]

His generator must have permanent magnets if it produce residual power after the power is cut off.???---Keoke--- :frown:

 

[RAC68]

Hi Keoke,

I was under the impression Mike had an alternator in his Healey, but after reviewing the comments, I see no mention of the type of generator he is using.

Mike, what are you using, Alternator or original Generator?

If Mike is using an alternator then my previous comments stand correct.

Ray

 

[Deleted member 8987]

We're still waiting to get the report of what happens when he turns the fan kill switch off under the bonnet and tries it.
THAT eliminates the fan if it makes no difference.

 

[bighealeysource]

Hey y'all,
Thanks for all the comments about this weird problem. Took her out yesterday
and as several of you had commented, IT"S THE PUSHER FAN !!! I switch it off
and engine shuts down immediately. Switch the fan on, takes the two or so seconds
to shut off. I am using the original equipment generator BTW. As long
as it is not something that could cause any damage, not concerned with it. I
am going to call the Petronix folks and see what they might recommend and will
let everyone know. THANKS again for all the comments and help.
Regards,
Mike

 

[Deleted member 8987]

Well, electronics being what they are, you often don't want a brownout condition in your power, you want it on or off.

So, easy fix is to wire in a fan relay, so when you turn the ignition circuit OFF the relay drops NOW and no brownout.

 

[Randy Forbes]

Well, electronics being what they are, <span style="font-weight: bold">you</span> often <span style="font-weight: bold">don't want a brownout condition in your power, you want it on or off</span>.

So, easy fix is to <span style="text-decoration: underline">wire in a fan relay</span>, so when you turn the ignition circuit OFF the relay drops NOW and no brownout.

That would be my (and Kenlowe's) recommendation :wink:

 

[bighealeysource]

Hey Randy,
My on/off toggle switch is located on the frame bulkhead very close to the
turn signal flasher - kind of out of site on purpose. So I have the power
lead from the fan to the toggle and from the toggle to a 30 amp fuse and then
the fuse lead to a hot lead on the fuse block when ignition is on. Should
I install the relay in that circuit somewhere ?
Thanks,
Mike

 

[Deleted member 8987]

Power into the relay points, power to the fan off the other relay contact, coil of relay one side to ignition, the other side of the coil to earth.

Leave your switch and fuse, route battery power through fuse to switch, use the output of the switch as power to relay points.

Easy, and unobtrusive.
You can get small relays that will fit right next to the fan.

 

[Randy Forbes]

Power into the relay points, power to the fan off the other relay contact, coil of relay one side to ignition, the other side of the coil to earth.

Leave your switch and fuse, route battery power through fuse to switch, use the output of the switch as power to relay points.

Easy, and unobtrusive.
You can get small relays that will fit right next to the fan.

Yeah, what he said...

 

[Cottontop]

Should I install the relay in that circuit somewhere ?

Mike,

Use the schematic that I put into this thread on 9/7/10 (above). A 30 or 40 Amp relay will cost about $3 at Radio Shack, but I have 40 of them and will send you one if you need it. The SPDT switch will run about $3 at any auto parts store.

That circuit will not let you have run-on and will provide you with Always ON, Always OFF, and thermostat control of the fan.

I use it in my Healey and my 66 Mustang GT FB.

Tim

 

[Deleted member 8987]

But it's far easier than converting your car to an alternator, buying Schottky diodes, mounting them, and still having the problem, eh?

 

[RAC68]

Keoke/Tim,

Good call. Congratulations.

Ray (64BJ8P1)