55 T-Bird power seat
 

I converted my 55 T-Bird over to 12 volt. Everything works but now the 4 way power seat that did work is not working at all.The car has 2 relays..This is my first question. Should I replace the two of them?

Also second question .Do you think I just burned out the 6 volt relay and not the actual motors? If so should I order two new 12 volt relays and start there before replacing the expensive motor?

Re: 55 T-Bird power seat
 

I don't think that the motors would be bad because you have 2 circuit breakers ahead of the relays and the motors. I would first check to make sure that you have power to the control switch,( the 4 way toggle switch) and than go from there. If there is no power at the switch,than follow the b-w wire from the switch back to the acc.terminal of the ignition switch. In that line that comes off the ignition switch,you will find a circuit breaker.
There are 2 circuit breakers in the seat electrical system and if I am not mistaken,they are both under the instrument panel. I would not replace any parts until you know where the problem is.just my opinion. Good luck.

Re: 55 T-Bird power seat
 

"The ... seat motors ... will work on 12V, but they will run very fast. The seat motor running too fast should be no problem." (from this link...)
https://www.ctci.org/battery-for-6v-to-12v-conversion/

The 6v seat motors in my 12v converted '55 Bird work fine if I ever use them, instead of just leaving the seat all the way back & down.

Times 2, that's always a good opinion.

The '55 Bird wiring diagram I have shows two main power wires to the seat motor controls with a circuit breaker in each.
One wire is from the Accessory terminal of the Ign switch and the other comes from the Battery terminal of the starter solenoid.
You can start at the power source(s) with a volt meter or test light and work toward the motors until you come across a connection without available power.
Since the car wiring was likely bumped around a bit while being worked on the problem may be a lack of power or ground, often somewhere simple. (like the broken circuit breaker I found under the dash)
.

Re: 55 T-Bird power seat
 

One of the two motors (up and down) works fine. It is the other (back and forth) mode that is not working.....So with the key on ACC. and using the back and forth seat switch I got power to the relay but nothing past that. Looks like my relay is shot. Should I purchase a 6 volt or 12volt new relay?

Re: 55 T-Bird power seat
 

Do you have a '55 T-Bird wiring diagram that shows the seat motor circuits? You should have one.

The wiring diagram I have shows a large yellow power wire (with a 40A circuit breaker) coming directly to the front/rear seat motor relay from the Battery terminal of the starter solenoid, along with wires from the 4-way seat switch.
If there's no power on that yellow wire terminal on the seat relay it would prevent the seat from moving horizontally.
I'd assume this separate front/rear power wire was done done to allow the seat to move back for easier entry before the Ign key was in place.
The up/down seat motor gets its power from the Acc terminal of the Ign switch.
Disclaimer: I've not compared the actual seat motor wiring in my '55 to the wiring diagram, unless it quits working at some point in the future.

The relay may indeed be bad but having the wiring diagram to work from for better testing is a good thing too. If you buy a new relay I'll suggest the 12v version. Its coil may handle 12v power better than a 'replacement' 6v version made who-knows-where. But the voltage and current sort of offset each other so it's a tossup.

Re: 55 T-Bird power seat
 

if you take the cover off the relay you may try cleaning the points with emory cloth not sand paper.if you have a points file that will do the job

Re: 55 T-Bird power seat
 

Got it working Thanks...What happened is when the seat was lowered and the run forward or backward at one time.... it pulled a wire off the back and forth motor. Hooked it up and works great. Thanks for all that replied.

Re: 55 T-Bird power seat
 

Love happy endings!