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Electronic signal flasher
1999 Jeep Wrangler

Electronic signal flasher

(1999 Jeep Wrangler)
1999 Jeep Sarah 4.0 A/T ... I was planning to change out all lighting with LEDs. In preparation I changed the signal flasher out to an electronic version to prevent possible hyper-flash.
Every thing worked fine (turns and hazard) however the vehicle will not start with that flasher installed. Almost like the neutral safety switch had been disconnected. Go back to the original and the motor starts.

Why??

Thanks for your time
Tags: electronic flasher, signal, hazard, jeep, wrangler
1 answer & 10 comments
Popular Answer
on February 10, 2019
You mean the starter motor will not CRANK the engine with the LED flasher installed?

Should be able to remove the flasher altogether and still crank engine..

Unfortunately this requires *hands-on* evaluationn.
Sign in to reply
on February 10, 2019

You can always add resistance to signal lights circuit - then use OEM flasher.
on February 10, 2019

Never heard of any such problem - I’ve been in the business for a little while - 45 years!
on February 12, 2019
I did a bit more research ... some of this is speculation because the wiring diagrams are very hard to follow. It looks as if the signal flasher is tied to the neutral safety switch circuit. Power needs to pass through the normally closed contacts in the flasher to make up the circuit to the starter relay (shiftier in park) which in a mechanical relay would be the case. In the electronic flasher the NC contact is dead until the flasher is activated via the blinker switch or the hazards switch, hence no voltage passing through to NC contact. Been tinkering with hot rods and racing engines for 50+ years and this one had me stumped until I stepped back and rethought for a day. Thanks.
PS ... (from previous post) In my mind adding resistance to the circuit seems to defeat one of the main purposes of having LED lights, but that is just me.
Again ... Thank You very much.
on February 12, 2019
Resistance is commonly used with LED retro - it has no affect on lumens of LED’s which unlike incandescent bulbs will operate optimally with varying voltage / current.

Resistance is simply to trigger the OEM flasher.

As for the flasher being related in any way to the PN safety switch - that is a new one on me.. Keep on it - you’ll figure it out.

All I can offer at this point is GOOD LUCK!
on February 12, 2019

It’d be highly unlikely for a failed signal flash to leave the operator stranded - that’s just me.
on February 12, 2019

Let us know the final outcome..
Again - GOOD LUCK!
on February 12, 2019
on February 15, 2019
As an update: Yes ... If I remove the signal flasher the engine will not start. Did some more digging and finally found the problem. The people who had the Jeep before me had a Viper car alarm installed. The installer wired the relay so the car could not be started if the flasher is removed. This also defeats the starting circuit if the alarm is sounding.
So the only thing left to do is defeat the alarm shut off (rewire back to stock) or resistors in the lighting.

Thanks for all the help,
Dave
on February 15, 2019

Well I’m be dipped in s - - t ... Very poor install procedure for the aftermarket alarm! .. Which is junk to start with as far as I’m concerned..

No way to diagnose according to protocol with an altered system.

Glad you figured it out - probably easier to add resistance..

I have no idea why people have those aftermarket alarms installed - they more trouble than worth - done been there with many customers over the years.
on February 15, 2019

Sometimes it’s not that difficult to just remove the alarm system - however I don’t know the situation here.

Thanks for the response.

Good luck!
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on February 10, 2019
You mean the starter motor will not CRANK the engine with the LED flasher installed?

Should be able to remove the flasher altogether and still crank engine..

Unfortunately this requires *hands-on* evaluationn.
Sign in to reply
on February 10, 2019

You can always add resistance to signal lights circuit - then use OEM flasher.
on February 10, 2019

Never heard of any such problem - I’ve been in the business for a little while - 45 years!
on February 12, 2019
I did a bit more research ... some of this is speculation because the wiring diagrams are very hard to follow. It looks as if the signal flasher is tied to the neutral safety switch circuit. Power needs to pass through the normally closed contacts in the flasher to make up the circuit to the starter relay (shiftier in park) which in a mechanical relay would be the case. In the electronic flasher the NC contact is dead until the flasher is activated via the blinker switch or the hazards switch, hence no voltage passing through to NC contact. Been tinkering with hot rods and racing engines for 50+ years and this one had me stumped until I stepped back and rethought for a day. Thanks.
PS ... (from previous post) In my mind adding resistance to the circuit seems to defeat one of the main purposes of having LED lights, but that is just me.
Again ... Thank You very much.
on February 12, 2019
Resistance is commonly used with LED retro - it has no affect on lumens of LED’s which unlike incandescent bulbs will operate optimally with varying voltage / current.

Resistance is simply to trigger the OEM flasher.

As for the flasher being related in any way to the PN safety switch - that is a new one on me.. Keep on it - you’ll figure it out.

All I can offer at this point is GOOD LUCK!
on February 12, 2019

It’d be highly unlikely for a failed signal flash to leave the operator stranded - that’s just me.
on February 12, 2019

Let us know the final outcome..
Again - GOOD LUCK!
on February 12, 2019
on February 15, 2019
As an update: Yes ... If I remove the signal flasher the engine will not start. Did some more digging and finally found the problem. The people who had the Jeep before me had a Viper car alarm installed. The installer wired the relay so the car could not be started if the flasher is removed. This also defeats the starting circuit if the alarm is sounding.
So the only thing left to do is defeat the alarm shut off (rewire back to stock) or resistors in the lighting.

Thanks for all the help,
Dave
on February 15, 2019

Well I’m be dipped in s - - t ... Very poor install procedure for the aftermarket alarm! .. Which is junk to start with as far as I’m concerned..

No way to diagnose according to protocol with an altered system.

Glad you figured it out - probably easier to add resistance..

I have no idea why people have those aftermarket alarms installed - they more trouble than worth - done been there with many customers over the years.
on February 15, 2019

Sometimes it’s not that difficult to just remove the alarm system - however I don’t know the situation here.

Thanks for the response.

Good luck!

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