1955 Ford convertible top relay. Can I use the original 6 volt relay with a 12 volt system? I can find no replacements available, 6 or 12 volt.
Are you using the original top motor,the 55/56 top relay is different then any other top relay I have seen as the top switch does not have any power going through it and it grounds the relay to make the top motor work. All the other systems I worked on the top switch delivers power to activate the relay but not the 55 Ford system,when I converted my 55 sunliner to 12 volts I used a 90s Chrysler Le Barron top motor and had the guys at work wire me up relays that were activated by ground to work that top motor. The 55 relay is actually 2 relays in one,one side for up and the other for down and most newer vehicles use two relays,if you want to keep it close to original find a 56 motor and relay but good luck in finding one as it might get expensive and the 57 and up system had power going through the switch.
There is a good chance that the relay will end up sticking if you run 12v through it. The top runs for a fair amount of time unlike a horn relay that is just a quick Blast (and I have even seen those stick on!).
The more I think about it try to find a heavy duty 6 volt resistor before the top motor and do not change a thing.
I have no desire to keep it original. I have a new 12 volt motor. If a 56 relay was available then I would not have a problem. So Jeff are you saying that using a 57 switch might be an answer?
If you use a modern pump and relay a 57 and up switch would be the way to go,you will have to run a power lead to the switch then since there is none going to the 55 switch. You can find relays that will work off ground instead of power and keep the original switch but you will have to find someone who installs electronics to make it work for you,I have the 90s Chrysler top motor and relays with two more relays that use ground to activate to activate the Chrysler relays which is complicated but works. I work at a place that sells car audio so the guys who install that stuff know relays and had them wire up the relays for me.
don't know if this would work for you, but i used a starter relay from a mid-'60s mopar on my shoebox's overdrive.
I think I paid 15 dollars for the top motor and relays,it fit like it was made for it and the original hoses screwed in and just had to figure out the wiring. Could not see paying big money for a top motor when these were plentiful in the junkyards at the time.
Rich [Texas 57] posted this diagram from the 57 Ford manual for me over on the 57fordsforever forum. I was surprised to see no relays were used. Guess that is why the universal top switches are 50 amp. Thought I would post it here in case anyone else has been watching this thread.
I do not think relays were used until the 80s and it would be wise to wire them up to keep so much power going through the switch.
I have already set it with with relays. Just was surprised Ford did it that way in 57. If you read the manual it says that maximum amps under stall of the top is 47 amps so I guess Ford felt the switch would be ok. I will bet that the majority of 57's on the road are still set up that way.
GM used no relays until 71 and presume the first Chrysler with a relay was the Lebarron in the mid 80s.
70-72 Olds Cutl*** did not have relays. People would hold the switch down when the motor had faulted to ground and melt the switch. For several years I was rebuilding the switches because there were no reproduction switches available. It was a good side line while it lasted.
The full size GM scissor frame convertibles had a relay but I still had to replace many switches over the years,that is the worst design of a convertible I have seen so far
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