Turn signals

Have fun finding the flasher. The flasher on the fuse panel is for the hazard lights. The real turn signal flasher has several different possible locations depending on the year model and the tilt of the moon. Some are on the back side of the fuse panel, some are by the radio and some are over near the glove box. It is an easter egg hunt...

As mentioned above, the flasher for the turn signals is burried somewhere in the dash. I found it easiest to find by opening the glove box, squeezing both sides of it so it opens all the way (just hangs on it's hinge) and the flasher was right there. That's where it usually is, behind a/c, heater controls. I actually changed it once while driving down the highway when my blinkes just stopped working I pulled the hazard flasher out and made my turn signals work, they were more important at the time. Here is a picture.

Check the wiring to your multifunction switch. The turn signal relay has a wire that runs right to the switch (check a wiring diagram for proper color.) .. I accidentally pulled the wire out of the MF switch on my '88 during a heater core swap, and it took me forever to trace it to that wire.

Hey guys i have an 89 mustang and i have the a turn signals problem too. The fuse is good, multi switch is brand new, new flasher, new bulbs, but turn signals dont work. The arrow on the cluster lights up and my bulbs get brighter but thats it. No blink/flash. The other bulb light up but my turn signals dont work and my flasher doesnt work either. Any ideas??

Armando Carrera said:

Hey guys i have an 89 mustang and i have the a turn signals problem too. The fuse is good, multi switch is brand new, new flasher, new bulbs, but turn signals dont work. The arrow on the cluster lights up and my bulbs get brighter but thats it. No blink/flash. The other bulb light up but my turn signals dont work and my flasher doesnt work either. Any ideas??

Click to expand...

In the fuse panel under the dash there is a silver cylinder. Replace it. Its the turn signal flasher.

Read my post on turn signal flasher location along with mustangphil's post & picture. The turn signal flasher can be elusive to find...

Ah yes thats right. Ford liked to hide them. Behind the glovebox and other ridiculous locations. Good luck!

@Armando Carrera
If the flasher does not work, I have a question and some other ideas to check. Do both both front and rear signal lights light up steadily? My Mudtang's battery is out right now, but it used to be the front and rear lights alternated when blinking. And in our van, a bad bulb made the system not work. In my classic GM, a bad ground in a tail light made the system stop too. So after replacing the flasher and making sure the switch wiring is plugged in (which will probably do it) I would start checking bulbs, power flow and grounds. After that, there is just the switch and. An exorcism.

Sorry about the typos. I need coffee.

Frankly, the moment i move the turn signal switch my cluster dims. Whether its for left or right, both front and rear bulbs just light up. Ive noticed that while its idling and i give it gas my cluster gets slightly brighter and my headlights get brighter. When driving, the gauge for my battery or voltage centers(headlights on). While on idle the needle stays centered but the moment i turn on my headlights it drops down close to the red area. Now my first assumption was a bad alternator but i did a charging/starting test and the alternator tested good. Could this also be affecting my turn signals?

Armando Carrera said:

Frankly, the moment i move the turn signal switch my cluster dims. Whether its for left or right, both front and rear bulbs just light up. Ive noticed that while its idling and i give it gas my cluster gets slightly brighter and my headlights get brighter. When driving, the gauge for my battery or voltage centers(headlights on). While on idle the needle stays centered but the moment i turn on my headlights it drops down close to the red area. Now my first assumption was a bad alternator but i did a charging/starting test and the alternator tested good. Could this also be affecting my turn signals?

Click to expand...

Yes, a low voltage would cause the flasher not to work.

You need to beg, borrow or buy a voltmeter or DVM. Places like Harbor Freight have cheap ones that will work for simple tests like you'll do to find your problem.

Check the voltage across the battery terminals with all the electrical turned on and the engine running about 1200 RPM. You should see 13.8-14.2 volts

If the voltage check is good, then the problem is likely a bad ground. Here's some help in that area...

Grounds

Revised 28-Oct-2012 to add signal ground description & possible problems if it is bad

Grounds are important to any electrical system, and especially to computer controlled engines. In an automobile, the ground is the return path for power to get back to the alternator and battery.

Make sure that all the ground places are clean and shiny bare metal: no paint, no corrosion.

1.) The main power ground is from engine block to battery: it is the power ground for the starter & alternator.


2.) The secondary power ground is between the back of the intake manifold and the driver's side firewall. It is often missing or loose. It supplies ground for the alternator, A/C compressor clutch and other electrical accessories such as the gauges. The clue to a bad ground here is that the temp gauge goes up as you add electrical load such as heater, lights and A/C.

Any car that has a 3G or high output current alternator needs a 4 gauge ground wire running from the block to the chassis ground where the battery pigtail ground connects. The 3G has a 130 amp capacity, so you wire the power side with 4 gauge wire. It stands to reason that the ground side handles just as much current, so it needs to be 4 gauge too.

The picture shows the common ground point for the battery , computer, & extra 3G alternator ground wire as described above in paragraph 2. A screwdriver points to the bolt that is the common ground point.

The battery common ground is a 10 gauge pigtail with the computer ground attached to it.
Picture courtesy timewarped1972


Correct negative battery ground cable.



See http://assets.fluke.com/appnotes/automotive/beatbook.pdf for help for help troubleshooting voltage drops across connections and components. Be sure to have the maximum load on a circuit when testing voltage drops across connections. As current across a defective or weak connection, increases so does the voltage drop. A circuit or connection may check out good with no load or minimal load, but show up bad under maximum load conditions. .

Voltage drops should not exceed the following:
200 mV Wire or cable
300 mV Switch
100 mV Ground
0 mV to <50 mV Sensor Connections
0.0V bolt together connections