I continue to blow the fuse from the turn signal switch. I have both lights and brake light at the rear but no turn signals either side. The tail lights have been rebuilt and all the bulbs are good. I’ checked the wiring and can see no wiring problems. I have all the relays out. Is there a way to test them while there out and can a shorted relay cause a dead short. The emergency flasher will not work either.
Thanks
How does the turn signal switch itself look? Sometimes they melt under the load of all the taillight bulbs.
Which year of Cougar? The Emergency Flashers draw power from a different source, which is protected by a circuit breaker. However, that source also powers the brake lights, so if they are ON, the power to the Emergency Switch should be good. Definitely pointing to the steering column area as a possible short point.
Best thing to do at this point is check for ground shorts on both sides of the Turn Signal Switch connector. Disconnect the battery, then you want to connect the ground lead to the frame, and connect the red lead to each connector post or plug, one at a time. If you find a 0 ohms reading (or close to it), note the wire color and we can reference the circuit in trouble.
Relays can be checked for shorts by metering from each connector lead to ground (the can), however they usually fail in the OPEN state, not shorted to ground.
Checking light system motors and relays in the ‘hot’ state requires a 12v supply, which can be cobbled together from a 12v car charger plug and an 115v ac to 12v’Lighter Socket’ adapter, or some jumpers and your battery.
However, you problem does not appear to need this testing. (as above)
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Some reference on the connections INTERNAL to the TS Switch can be found here:
http://www.thuntek.net/cougars_unlimited/1967-68_TS_Connectors.PDF
I have one quick question for you guy. I think I have isolated the problem after checking all the relay. Once I ground the base I can energize the terminal and hear the relay open and close, but the turn signal relay will not open and close the same as the others. When grounding the base and energizing the terminals, it will not open and close. So I check energizing the middle terminal and have 12 volt to both outer terminal. Check each of the outer terminals and get 12 volt on all the terminals. I may be wrong but I thought energizing the terminal would either open or close on side or the other. What do you think?
Thanks
Some times the names are switched in the diagrams from the Ford Manual to the Osborne book, so lets be sure which relay you are talking about. The Osborne book is incorrect here I think. It labels the Turn Signal relay as the Indicator relay, which has 4 pins and is for directional control.
The Turn Signal relay has only 3 terminals and creates the ‘flash’ for the indicators. Now it is a bit different from 67 to 68 internally. For a 1967, it SHOULD NOT have 0 ohms to the can from ANY terminal, that would be a short.
This relay has normally closed contacts.
The '68 relay has the coil in between terminals 1 and 5. It can be recognized by a ground tab soldered to the can, which is not on the '67 relay.
Terminal 3 is connected to ground, except when energized it is open. This connection in a '67 would create a dead short. I am not sure why it is wired this way for the '68, I’ll have to check that out again.
The readings for the turn signal relay are normal. It is different than the rest. The coil is inline rather than going to ground (the can) as the others. It has 12v in, 12v out (to feed the Sequential Motor and contacts), and a 12v ON/OFF flasher signal out for the INDICATORS.
It opens and closes based on a certain current level, and is very tricky to get a reading on, it works or doesn’t.
This coil has a very low resistance, so it would appear that all terminals are connected based on a resistance measurement ('67), and dead short from Term 1 to 5 and 3 connected to ground('68).
If that is the case, it appears to be a good relay it appears that every circuit for turn signal goes through this relay. Once disconnecting the turn signal relay ( by the way, it is the 3 pin relay) all the other relay energized even in the trunk. Checked the sequ motor and it does work the cam. I am getting .1 ( one ) omh across the terminals. put it back in and still blowing the fuse. I will go back and ground the chassis tomorrow and make sure I do not have a ground somewhere. Where ever the ground is, it is a good one. Doesn’t take much for it to blow.
That is a good sign. Be sure the relay is NOT from a 1968. That relay supplies the Sequential Motor and indicators. The motor could be shorted, it has the most potential for trouble IMO.
No I have own this car almost thirty years and this is the second rebuild. Only could only do the minimum then with small kid to pay for. Finally got the chance to do it right this time. It all 67.
Nice! Well, you could unplug the Sequential Motor, and leave the relay plugged in. The only lamps that would light up would be the dash indicators, but they should work in L/R mode, but no flash probably. That isolates the dash.
The Sequential Relay should click L/R as well, but has not voltage to pass when energized. Brake lights should still work, but go dark on the side the Turn Signal switch is on.
You can put voltage on the motor when removed (Orange/Green wire to ground on can), but be careful if it is shorting, you could get a jolt!