Muf

Is there somebody who understands the principles of how the blinkers and the relay work? Maybe you could help me track the following problem.

I have a 79 targa (Euro car, maybe american cars have different blinkers - they surely have some extra side markers...)
Some time ago the blinkers stopped working. I have replaced the relay. OK, the blinkers worked fine since but the green dash indicators did not work anymore the way they used to. When turning to either side, BOTH green lights blink with a weaker intensity (like if connected serially).
I was living with this till recently when I bought a different relay, a used one but from a reputable shop. The "new" one does not work at all. It blinks once or twice and then nothing. Both blinkers and dash are off. The relay might be faulty, as it was not new, but it seems like too many coincidencies in the relay problem.

My questions are:
Are the Porsche relays identical like in other cars, for example VW (I tried the VW relay and it showed the weak dash indicator symptom)?

Could there be some error in the circuit resulting in the above indicator issue?

I tried more relays from different cars. Some relays had only three pins. But they work the same as those with four pins. What is the fourth pin for?

Thanks for any help...

srf506

I guess the description of the remedies already tried have me confused. Have you used the right relay in the car? I'm confused about all of these VW and "used" and the original replacement relays. Were they the proper Bosch relay and part number for the car? Have you used a meter and made sure you've go the right current to the relay? Have you checked all of your grounds? Are we referring to a real relay on the fuze block or are we talking the blinker itself? Another thing to check might be the turn signal switch.

It can be a lot of different things, but until you verify you've used the OEM relay in the system it will be hard to isolate. In addition, if you put a nonstandard relay in the car if its electrical characteristics are different than the OEM one you might have damaged something up or down the line.

Can you give us some more info on exactly what you've done to this point? Maybe then we can give you some more help.

Muf

Sorry if my description was confusing.
Currently I am using a generic relay. It is not OEM. This relay works fine for the lights outside, only on the dashboard, the green arrows blink both together.
The relay we are talking about is located inside the firewall, actually behind the left gauge but one can reach it from the trunk.

VA911

i have the same problem. no idea why it does this though

theiceman

I don't have a schematic in front of me but a couple of things come to mind. The circuits do work independantly with the flasher relay but the frequency of flashing is ependant on load current, this is affected by total resistance ie correct light bulbs in place including those in the dash.
In addition the circuit is designed to work as one unit when activated by the hazard switch, perhaps your problemm could be there ? ..not likely but something to keep in mind.

As mentioned the first thing to do is get the correct relay, perhaps someone around has a similar car ? if they are willing try your relay in their car , as if it is a bad relay it will not work in their car , if the car is frying the relay you don't want to put their relay in your car.

Once you eliminate the relay move on from their. I understnd you have tried other relays , but I am not convinced .. yet ..

srf506

I concur with theiceman. These cars were still pretty much analog, they used current and resistance to make things function versus 0s and 1s. I was always taught to eliminate the obvious. What made you suspect the relay to begin with? Since its not an OEM relay just because it fits doesn't mean it has the same electrical properties. Get the right one and install it. If that doesn't solve your problem keep making sure you always have the right power and a good ground. All circuits must be complete with a path back to where the power came from. The hazard flashers is a good place to start since the dash indicators are acting like that. Might be a current leak from that generic relay. Good luck, I always hate electrical gremlins. Its usually two days of checking and isolating the fault and then a ten minute repair once you've got the parts in hand.

Droops83

Pull your hazard switch out of the dash and take a look at it. They can corrode pretty badly. If yours looks bad, then it could be your culprit. The entire turn signal/flasher circuit is powered through this switch. Try a different hazard switch. I had customer car that had similar symptoms if i recall correctly, and the hazard switch was the culprit. Also put the correct relay back in.

---Chris A.

onlycafe

i think it could be a bad bulb, or a bad ground.

jester911

Check the grounds.The ground wires for the light housings themselves are connected to a bolt that holds the rear bumper shock. You may have to completely remove the housing to get to it. I recently installed new rear housings and forgot to tighten those bolts. When I put the brake pedal on both green arrows would light up faintly. After tightening the bolts with the grounds it went away.