I’ve a 1973 Pantera.  New to me.  I’ve got a fast turn signal (both directions) but only when using turn signals, not using hazard when it blinks normally.

All bulbs (1157 front and single element bulbs in back) are working (including the jewel Indicator in the tach) and I know the same flasher works the hazard and the stalk controlled indicators.  The flasher itself is a stock three-prong in the driver’s footwell.

what can it be?  I even put a 5ohm resister across the tach jewel to increase load when blinking with no effect.  What am I doing wrong?

usually a fried bulb causes fast blink, all working. 

any ideas?

Original Post

Maybe a bad ground somewhere, have you checked voltage? The stud under the dash with multiple ground wires is quite notorious for being the culprit of bad grounding.


I am using regular incandescent 1157 in front and single filament incandescent bulbs in back. In the speedo it is the stock 2w incandescent.

I will check the ground under the dash and at the fixtures too.  I've already used dielectric grease on the nylon connectors at the hazard switch and at each of the fixtures.

are you for sure you mount the bulbs in front on the right way ?


from what time you have a fast turn signal ?


It is normal speed when hazard switch is used and fast when the turn signal indicator is used.

That is the great puzzle!

from what I know the hazard has always a normal speed, even when one of the  bulbs is removed.

thinkin the front the parking light 5-10 w is blinking by using the turn signal.

and the 21w burns when the parking lights are on

@CPM posted:

that is a 21w bulb on the taillight indicators

That is OK , and  when into the front the wiring and bulbs are mounted as must be , try an other blinker relay .

But this  isseu happens me also once , and I notice that the wiring on the front parking /turnsignal are  switched .

to be sure check the front bulbs again , and check  the wiring if they are on the right way connected and if like Julian say there is bad ground .

Also try this, parking lights on, ignition switch on and push the brake pedal (brake light), turn indicator on .

and look if all lamps are flashing  


I had the same issue with my front driver's side turn signal.  I replaced the bulbs, it would be normal for a moment or two and then as soon as I got back into the car it would go to double speed.  The contact aparently was not very good, we cleaned and bent it forward a bit and seems to be working.  Now, I have no rear brake lights which we think we've isolated to a new brake switch which is going on this week.

When the brake lights are on and either blinker is on (still fast flash), there is a slight flickering of the brake light, which really seems like a ground problem.  I cleaned the grounds at both tail lights to no avail.   Might still be somewhere else.

Someone mentioned a nylon multiplex plug in somewhere near the coolant tanks might be worth checking.  I'm not seeing that plug.  Is it visible from under the car?

I'm running out of ground ideas.  Again, this is NOT happening with the hazard, which operates at normal click speed.

The plug is a big red square plug, on the passenger side, IIRC  It joins the smaller harness to the rear of the car to the main engine bay harness.

My pen is pointing at it in the two attached pictures.


IIRC - isn't there some terminal "eyes" on each of the taillight buckets?  I am sure you have checked those as well?

It still sounds crazy that the Turn Signal and Hazard Flasher behave differently...  maybe the circuits ground differently.

Hope this is helpful.IMG_9345 [Large)IMG_9346 [Large)





Images (2)

Here's the circuit, if you don't have it. 

The only difference I see in Emergency vs. Turn Signal is the fact that the Emergency Flasher Light grounds to chassis at "31".

Does the light in the Tach blink?





Images (1)
@CPM posted:

When the brake lights are on and either blinker is on (still fast flash), there is a slight flickering of the brake light, which really seems like a ground problem.  I cleaned the grounds at both tail lights to no avail.   Might still be somewhere else.

very slightly flickering is OK into this situation.

Rocky - thank you much.  Yes, I did have the circuit from that other website (great website).  My car also has the Pantera Elec ATO fusepanel replacement which is really nice and was well installed (I think!) by others before me.  Thank you too for the illustration and location of the multiplug. - I'll look for it from the topside and hoping that squeezing connectors and dialectric grease may help, which it has already on some other plugs behind the dash.

Yes, I did ensure I have good grounds now for the rings on both tails - no impact yet.

Simon - thank you as well.

Again, the puzzler for me is how the Haz can work fine while the blinker is fast on both sides.  the flasher itself is the same for both (its the pink wire output).

I haven't yet gotten to the below dash ground.  That and the plug on the pass side in the engine compartment are my next.

@rocky posted:

It still sounds crazy that the Turn Signal and Hazard Flasher behave differently...  maybe the circuits ground differently.

from what I remember the hazard flasher Always works slow , even when one or all the bulbs are out of the lighthousings .

still thinking the problem is into the front parking/turn lights.

other wise try to replace the black flasherbox

One thing I don’t understand is how the light in the tachometer works. It looks like it has to ground through the “other” tail light/front marker light, which should make those lights blink as well.

I am wondering if that part of the circuit is correct?



Last edited by rocky

The difference between the emergency flashers and turn signals is the number of bulbs. I would replace the flasher unit with an electronic one that does not depend on the current load to set flasher rate.

Rocky, yes the dash indicator light grounds through the opposite side front lamp.


The bulb in the tach will affect turn signal speed, but not emergency flasher speed. If there is an LED in the tach, one direction will flash faster than the other (and the tach LED won't work). 

If the relay is current dependent, then it should flash faster in Emergency mode--since all bulbs are heating the relay faster. 

 At first I saw the 120 ohm resistor and the dimmer circuit and thought they'd be relevant, but as I see the switch drawn it simply shares the dimmer current to the lamp in the emergency switch until the switch is pressed...then the emergency lamp switches in unison with the external lamps--Lee

Last edited by leea

The bulb in the tach is not LED - its standard 2w incandescent.  I'll do some checking on the left front ground and then plan to change out the flasher.

Doesn't the hazard run the same lights as the turn signal?  There would be more bulbs in circuit (less resistance) on hazard in than when signaling, where there's just the front, rear, and 2w indicator in the tach.  (I think I just restated what leea said).

Incidentally, I don't think my dash dimmer is doing anything at all.

..This has confused me about the discussion, because my experience was that a poor ground or open bulb created a slow blinker---since for thermostatic types of blinkers, the current draw heats the relay internally, causing the bimetallic to switch off...And this is just the opposite of what you are seeing, but no matter---if the blinker is looking for current, he's going to find more of it in Hazard mode. In my world, the hazard would be "On" for half the time as in turn-indicator, but the cool down-time of the bimetallic not change. 

  In my world of thermostatic blinkers, though, there is no ground at the blinker: bright bulbs everywhere are all that is needed, the only ground that matters is the ground at the bulbs (as these cause the current needed for the heater in the relay). This is the Mangusta and maybe early Pantera. But the new-fangled Pantera blinker shows a ground. So if its measuring current, well, could be that it is working just fine. If it is instead a simple timer (as I'd expect all modern blinker relays), only then is this a mystery !  

At least from the schematic, the dimmer is irrelevant to the circuit when the hazard button is pressed; unpressed, the bulb in the dimmer switch is just following the other gauge bulbs, which won't have any power at all if the lights are off. When pushed, the bulb at the switch just becomes another load that affects the timing...and then only somewhat (its only the ant on the ant hill...)

My suggestion---don't press the hazard switch, and everything will be OK Lee




Solved - replaced driver footwell flasher with O'Reily's off the shelf EP35 flasher.  Chased grounds, etc to no avail.  The replacement package says "LED Compatible" - my bulbs are incandescent.  The Tridon piece it replaced said "failure indicator".  So I'm kind of cheating since the Tridon product sensed a failure somewhere (all bulbs working).  The off the shelf version is evidently electronic and is not amperage dependent.  So there may be a gremlin somewhere, but the fast blink is solved.

Last edited by CPM

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