diode isolate parking lights 89 vw jetta

Printed From: the12volt.com
Forum Name: Car Security and Convenience
Forum Discription: Car Alarms, Keyless Entries, Remote Starters, Immobilizer Bypasses, Sensors, Door Locks, Window Modules, Heated Mirrors, Heated Seats, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=66390
Printed Date: July 15, 2025 at 8:04 AM

Topic: diode isolate parking lights 89 vw jetta

Posted By: redshift
Subject: diode isolate parking lights 89 vw jetta
Date Posted: November 16, 2005 at 4:17 PM

I'm intalling an alarm in my 89 Jetta GLI and I'm wondering which would be the proper way to isolate the parking light switch with a diode. I have one output which sends +12v to the parking lights when the switch is in the right position. I need to tap the parking light flash output into that wire. Which is the proper way?

Figure 1 - diode inline with parking light wire
posted_image

Figure 2 - diode inline with alarm trigger wire
posted_image

I want to do it the proper way and not backfeed any voltage where it doesn't need to go.

Thanks!

Replies:

Posted By: infinkc
Date Posted: November 16, 2005 at 4:29 PM

figure 2

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There are 10 types of people in the world, ones that understand binary and ones that dont.

Posted By: redshift
Date Posted: November 16, 2005 at 4:30 PM

Perfect, thanks!

Posted By: infinkc
Date Posted: November 16, 2005 at 4:34 PM

redshift wrote:

Perfect, thanks!

actually both ways work, the first way will also isolate it from the switch, if the diagram wants the lights used to isolate from the swith use the first, if they want it to isolate from left and right use the second. hope that helps, i read your post wrong at first

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There are 10 types of people in the world, ones that understand binary and ones that dont.

Posted By: KarTuneMan
Date Posted: November 16, 2005 at 4:39 PM

https://www.directechs.com/techtips/pdfs/resources/security/directed_techtips/1040.pdf

Look at "isolating dual parking light circuits"

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Posted By: redshift
Date Posted: November 17, 2005 at 10:53 AM

Weird thing is, all the online resources and manuals say there are dual lighting circuits, and the car has two parking light fuses, so there *are* dual lighting circuits, but they split at the fusebox after they exit the light switch, so at the switch there is only one pin to worry about. Lights all six.

Got it hooked up last night and it seems to work great. It immediately goes off when I reconnect the battery, which is weird, but I'll sort that out later.

Thanks for the help!