TheSamba.com Forums
 
  View original topic: running after ignition turned off - possible relay problem? Page: 1, 2  Next
arizonabuckeye Sat Jun 11, 2016 1:11 pm

Fires up nice and runs fine. When I turn off ignition it keeps running like nothing happened. When I pull the power from a Bosch relay to my MSD 6AN box it kills it. I checked the relay and it works fine without the car running - ~12 volts to the MSD with key on none with it off.

Have you guys heard of these sticking on in different circumstances? Like it functions fine without the car running but sticks with it on?

And to save the bother... I have the relay (instead of running the MSD straight from the ignition) because it also powers an external oil cooler.

Chip Sat Jun 11, 2016 1:18 pm

You need a diode in the wire going to the alternator light. VERY common issue. So common in fact that MSD has instructions for it.

http://www.msdperformance.com/support/troubleshooting_techniques/

TinCanFab Sat Jun 11, 2016 1:20 pm

Your MSD should have come with a resister in the kit. Wire it inline with your warning light wire at the alternator. The CDI box is getting back feed through that wire and keeping the spark going to the plugs. The MSD instructions have a section that talks about it. I just did this job on my bus 2 months ago

Mikedrevguy Sat Jun 11, 2016 1:24 pm

Good information for those of us who may not have purchased their MSD knew in box.
Rev.

arizonabuckeye Sat Jun 11, 2016 1:31 pm

So glad I didn't just swap out the relay thinking it was toast. I'll have to check into it more. The MSD is from the PO so I will have to check and see if it was done.

tattooed_pariah Sat Jun 11, 2016 2:26 pm

In the meantime, I've found that tapping the brakes draws enough power to the brake lights to stop the flow and kill the engine with mine..

Nowadays about 95% of the time it shuts off with the key, the other 5%, a quick brake tap does the trick..

Dale M. Sat Jun 11, 2016 5:08 pm



Radio Shack diode 2 @$1.99 ...

https://www.radioshack.com/products/3-amp-400v-diodes?variant=5717579653


Dale

Dale M. Sat Jun 11, 2016 5:10 pm

tattooed_pariah wrote: In the meantime, I've found that tapping the brakes draws enough power to the brake lights to stop the flow and kill the engine with mine..

Nowadays about 95% of the time it shuts off with the key, the other 5%, a quick brake tap does the trick..

Add a diode and never have to tap brakes again...

Dale

arizonabuckeye Wed Jul 06, 2016 11:49 pm

Would swapping the distributor bulb for an LED do the trick?

Drewmon Thu Jul 07, 2016 4:56 am

HOLY CRAP....

I've been trying to fight this issue for 2 months. I too have this same issue with my 66 (with MSD). I've just got so use to pushing the brake to stop the motor. I'll have to look into this ASAP. I'm so glad this topic resurfaced.

Does anyone know the resistor values or diode part number?

Bashr52 Thu Jul 07, 2016 5:03 am

arizonabuckeye wrote: Would swapping the distributor bulb for an LED do the trick?

Nope, may even make it worse (eliminate the ability to stop with brake tap) since LED's need less current to illuminate than a comparable incandescent.

Dale M. Thu Jul 07, 2016 7:08 am

Bashr52 wrote: arizonabuckeye wrote: Would swapping the distributor bulb for an LED do the trick?

Nope, may even make it worse (eliminate the ability to stop with brake tap) since LED's need less current to illuminate than a comparable incandescent.

Its the amount of current flow through incandescent bulb which is causes run on problem which more than a actual led will allow, problem with trying to use LED is it needs more circuitry to work as a ALT/GEN lamp indicator, the additional resistor in LED circuit then causes the run on problem problem because if increased current flow though resistor... The actually LED only illuminates because of current/voltage change across resistor...

This circuitry needed to use LED as ALT/GEN idot lamp...



Dale

[email protected] Thu Jul 07, 2016 7:10 pm

Drewmon wrote: Does anyone know the resistor values or diode part number?

Radio Shack # 276-1103

Drewmon Fri Jul 08, 2016 5:07 am

Chip B. wrote: You need a diode in the wire going to the alternator light. VERY common issue. So common in fact that MSD has instructions for it.

http://www.msdperformance.com/support/troubleshooting_techniques/

I looked through the MSD box and found the diode. I made a pigtail to attach to the Alt light (Had to wire the diode backwards because of the -/+ being reversed in the light cluster) and hooked it up. Now the VW actually turns off when turning the key off.

Thank you everyone. I thought the switch in my column was bad.

arizonabuckeye Fri Jul 08, 2016 8:53 am

Drewmon wrote: Chip B. wrote: You need a diode in the wire going to the alternator light. VERY common issue. So common in fact that MSD has instructions for it.

http://www.msdperformance.com/support/troubleshooting_techniques/

I looked through the MSD box and found the diode. I made a pigtail to attach to the Alt light (Had to wire the diode backwards because of the -/+ being reversed in the light cluster) and hooked it up. Now the VW actually turns off when turning the key off.

Thank you everyone. I thought the switch in my column was bad.

This is my project for the weekend. Any pics?

Mikedrevguy Sun Jul 24, 2016 2:12 pm

Have 74 super with external regulator:
Any reason the diode could not be inserted at the regulator side of the D+?

For those of use without any radio shack, any place carrying a 3v 50 will do?
Any suggestions?

Dale M. Sun Jul 24, 2016 3:08 pm

If you have run on with external regulator diode may fix, but wont hurt anything...

No Radio Shack?... Try local auto alarm/stereo store, ask for "blocking diode"....

Dale

Mikedrevguy Sun Jul 24, 2016 3:23 pm

So shouldn't need a diode with an external regulator?


Radio shack went out of business here.

Dale M. Sun Jul 24, 2016 7:22 pm

Have not heard of using diode on external regulator, but there is always a first.....

Stat it up, shut it off with key, if you have run on, pull wire off terminal 61 of regulator, if it dies, add diode, if it continues to run, problem is else where..

Yep most RS stores are closing, guess mother company is not surviving bankruptcy...... Sears/Kmart is next in line to close many stores....

Dale

Mikedrevguy Sun Jul 24, 2016 8:41 pm

Thanks, Dale. Appreciate the help.
Rev.



Powered by phpBB © 2001, 2005 phpBB Group