Convertible Top Relay Pin Out

[Ken Stevens]

Didn't know if I should post it here or in the convertibles forum. apologies if I am mistaken.

In the process of lowering my top after the header has unlocked, the relay is supposed to fire up the top pump and open the top solenoids. Mine does the former and not the latter. so I pulled the relay to test it but there are discrepancies with the shop manual when it comes to wire color. (I recently moved and cannot locate the top repair manual I ordered from Cashman, so I'm limited to the shop manual.)

Here is the relay removed from the car. It is the upper right relay as described in the manual. C1VF-15672-B with the 5 terminals numbered consecutively with #5 being a soldered connection to the outer case. There is a bar from connection point 3 that is screwed to a bus bar.

Relay Connections

The molded 3-wire connector contains a heavy yellow wire, a thinner yellow/white wire and an all white wire. The thick wire goes to pin 1, white to pin 2 and the thin yellow/white to pin 4. Pin 3 is unused.

Molded connectors

The manual identifies a blue wire feeding 12V, the yellow/white wire activating the relay, the all white wire triggering the solenoids, and a yellow wire activating the top/deck motor.

Note the wire colors

With no blue wire, am I to assume the exposed bus bar is the 12V feed? I just want to test the relay but with all the wires disconnected I would rather not reattach the battery lest I have a spark fest. So I could use some confirmation of my assumptions.

[Dan Szwarc]

That particular relay is supposed to be a dual-pole relay: Two sets of contacts. It dives the top/deck motor and the top solenoid (which diverts the fluid to the top).

The THICK wires drive the loads. I can see they are WHITE and YELLOW. There is a small yellow wire in the connector. That is the coil that activates the relay.

The bus-bar is the main 12V feed. It is considered the BLUE wire because that is the color of the wire that feeds the bus. Look for it. There actually should be two of them in parallel at the other end of the relay bank.

If you jumper 12V to the THICK WHITE wire, the top solenoid should click. THICK YELLOW will activate the PUMP when jumped to 12V.

I'm going to move this to the convertible sub-forum because it is very specifically for the convertible only.

[Ken Stevens]

Thanks for the help in clearing that up. I bench-tested the relay and unfortunately it works as it's supposed to. I say unfortunately because now it requires a deeper dive into the system.

1. Reinstalled the relay and connected the battery.
2. The top/deck pump works both ways as it raises and lowers the deck just fine.
3. There is wiring continuity from the relay to the solenoids and deck pump. To be sure, 12v applied to the solenoids makes them trigger just fine.
4. Tested for voltage on the yellow/white wire when the top switch is activated. all good, so limit switches upstream are OK.

Now while the reversible pump raises and lowers the deck OK, is it possible it's too weak to retract the top cylinders? 12V applied to the pump wires triggers the pump, but the sound is louder and more mechanical when feeding the yellow wire (cylinder retraction.) than the smoother sound I hear when feeding red wire (cylinder extension.) is that significant?

Man I wish Cashman would come to Michigan...

[Dan Szwarc]

Call John.

However, if the pump works, maybe the top solenoids aren't actually engaging?

[JAB]

Here are a couple of extra things to look at.

I notice that the relay plug shown in the photo has not been trimmed. John recommends trimming the rubber away so that the head of the connector is slightly exposed. This allows you to visually
confirm that the relay is properly plugged in.

Is your top system filled with brake fluid or Type F transmission fluid. The brake fluid systems are prone to internal failures due to the corrosive nature of the brake fluid. You may have developed blockage in a line, blockage at the cylinder inlet, or the cylinders may have seized up. Brake fluid will be clear to dark brown, while transmission fluid will be pink/red. John recommends replacement of lines, cylinders and motor (if the system is still charged with brake fluid) The upgraded system will be filled with Type F transmission fluid.

Regarding the relay, if the internal contacts are dirty, it may not provide enough power to activate the solenoids. Check that it is passing a full 12 volts.

Also, check the switches up stream to make sure they are actually passing sufficient power to click the relay.

Call me if you would like to go over all this.

John Brewer
303 562-8368

[Ken Stevens]

Thank you John for your reply. I will go out and make sure the relay is activating in situ, and that solenoids and pump are receiving their full 12v. As far as the system fluid, I am still operating on brake fluid and not type F. Top has worked flawlessly, albeit slowly, as long as I've owned the car. and when such time comes where I need to replace the whole system, I will indeed go to the Type F trans fluid.

The blockage of a top line is possible, but with two lines and two solenoids, my first reaction was the odds of both solenoids puking or lines clogging up was remote. There isn't even an attempt to raise the top, so I first sought an electrical fault. The deck rises and falls quickly as it always has but the top is totally inactive. Hence the search for a problem common to both cylinders.

If Cashman were coming to Michigan (I'm thinking Mid America Meet at the Gilmore in Kalamazoo this August) I would gladly hand over the cash to replace all the hydraulics and be done with it. But opportunity being what it is, I simply want to get the top down for the nice weather.

[Dan Szwarc]

Brake fluid is bad because it absorbs moisture and is corrosive. You should definitely look into converting to ATF.

Cashman hasn't been this far north in years. He gets too much business down south to bother coming up here.

[Ken Stevens]

Found a local hydraulic repair facility that sees no issue in replacing the pump, solenoids, cylinders and hoses. Electrics, not so much. Bringing it up to them today to discuss costs and part sourcing. I will keep everyone posted.

OK so here's another question: why does the top utilize two solenoids while the deck only one? Just curious.

[Dan Szwarc]

If you map It out, and because the solenoids block flow when off, you only need three. The fourth would be redundant.

[Ken Stevens]

But why doesn't the deck require two like the top does?

[Dan Szwarc]

It just doesn't. I'll draw it up. Remember, each solenoid is a valve, open or closed.

The logic is like a switch. A single pole switch can switch two circuits. And another switch off that and you can now switch three lines with two switches. Add another switch off another leg and you can switch four lines with three switches.

Hard to picture' which is why I gotta draw it. Once you see it, it will make sense.

[Dan Szwarc]

Here's how it works with only three solenoids. First, an ultra-simplified schematic of the top and deck hydraulics (no electric wiring shown).

In this scenario, the direction of the pump is irrelevant. The first case is to use the pump to operate the top. Red is fluid leaving the pump, green is fluid returning (or vice-versa for the opposite direction).

Deck: 1 & 2 ON, 3 OFF.

Top cylinders on the left. Deck on the right. Pump at the bottom. To run the top, solenoids 1 and 2 activate allowing fluid THROUGH the solenoids while 3 is off. All fluid goes into the top cylinders driving them up or down. Fluid transfer into the deck is blocked by solenoid 3, which is off. It cannot pass through the blue Xs.

Top with 1 and 2 OFF, 3 on

Now activate the deck solenoid 3 and keep 1and 2 OFF. Fluid passes into the deck cylinders and returns, but 1 and 2 block anything going to the top cylinders. Again, fluid cannot pass through the blue Xs.

There is no need for a fourth solenoid because the system only needs one (#3) to block flow to the deck when 1 and 2 are active. 1 and 2 block top fluid when the deck is active (#3 ON).

A fourth solenoid would be redundant because of the returning nature of the fluid. It's just not needed.

Make sense?

[Ken Stevens]

This is marvelous. No where have I ever read that explained. So I wonder if one of my top solenoids is indeed bad. I hear the clicking, but perhps one isn't functioning. The way I read your diagram, if either of the top solenoids remains shut, the top goes nowhere - up or down. Other than purchasing two new solenoids, is there a reliable way to test these things?

Thanks again for sharing this info! The cumulative knowledge here is amazing!

[dcm5652]

You need to connect a volt-meter to the output side of the relay and read the voltage when it is energized, if you have 12 volts or close then it is working if you do not then it is not working or you have a big current draw that is dropping the voltage to much, then you need to go the part that is triggered by that voltage and check what is wrong with it.

[JAB]

Regarding checking for a bad solenoid...
When you activate the solenoid, it should click, which is the sound made when the valve opens. If it does not click, then it has gotten gummy on the inside and is stuck shut. In many cases, tapping on the body of the solenoid lightly with a tool will free it up. The sound should be a solid click. If it makes a very light click, it may not be opening fully.

In the case of "no click" or "light click", remove the solenoid and run some brake klean though it. Activate it manually, tap it on a hard surface several times, and it will usually free up. Keep applying the brake klean until you get a nice solid "click" upon activation. Allow to soak overnight if necessary. If you can;t get it to click after all that, you probably need a new one.

John Brewer