Solid State Relay Board Options

[GregAmy]

I'm gonna sound redundant but...that's some damned impressive work. Well done. Wish I had five Benjamins laying around just so I could display that in my engine compartment.

[Cairo94507]

(IMG:style_emoticons/default/w00t.gif) (IMG:style_emoticons/default/smilie_pokal.gif) That is some very nice work there.

[02loftsmoor]

Well, it’s been about a year since I finished my 914 restoration, you can read all about it

HERE.

Everything works perfect except for the electrical problems I’ve been having with the relay board. I spent lots of hours trouble shooting electrical issues with the fuel pump. It turs out that my relay board had some bad connections for the fuel pump relay. After searching this site I discovered that the relay board is truly the weakest link in the 914. I tried to remove the epoxy bedding underneath the board and resolder the connections. This worked for a while but the fuel pump would sometimes stop and kill the engine. I finally figured out that the contacts for the fuel pump relay to the board were causing the problem. This seems like a never ending problem. I could buy another 40 year old used board and have the same problems.
So, to make a long story short, I decided to design a new relay board from scratch. I replaced the original electromechanical relays with industrial solid state relays. They have the same connection labels as the stock relays: 85 & 86 for the coil and 30 & 87 for the switch. The relays are available at most electrical parts dealers like Mouser or Digi-Key if one ever needs to be replace. They also use a lot less power than the original 914 relays. Also, since they are solid state and don’t have any moving parts they will last a lot longer and are more reliable. I also replaced the old ceramic fuse with a modern ATC style fuse and added an LED that illuminates when the fuel pump has power. This is great for trouble shooting fuel pump issues. It comes on for a few seconds after the key is turned on and stays on when the engine is running. Also, I removed the connections and plug for the rear window defroster. I used wires soldered to the connectors eliminating all of the riveted connections. All connections are soldered. To make the board I CNC machined the board out of high density polyethylene plastic.
I built a few extra boards to offset some of the development costs. They are quite labor extensive to build so I don’t plan to mass produce them. PM me if you want one. I would like to get $500.00 each. That includes the board with the solid stare relays. It does not include the voltage regulator. I used a solid state one from Pelican Parts. Both the stock and solid state voltage regulators will work.

Question for you Looks like they are. Are the Solid State Relays are serviceable ?? And is there a warranty?

[jfort]

Very cool. Nice work. I assume it won't work on a six?

[Mueller]

r


Question for you Looks like they are. Are the Solid State Relays are serviceable ?? And is there a warranty?

No affiliation with OP and hope not to step on ones toes....

SSRs are not serviceable, there are 0 moving parts inside, the plus to this is no mechanical wear or pitting. The downside is no way "activate" the relay without the power signal unless you use 12vdc jumpers which isn't difficult since you have a 12vdc power source (your battery)

Another downside is that while most of the time mechanical relays fail in the "off" position, SSRs have a tendency to fail in the "on" position when they fail which is not too often, we use and others use SSRs on million dollar equipment all the time so I really wouldn't worry about them failing (I wouldn't buy an SSR from some Chinese reseller like banggood for my car or equipment at home!) Stick with name brands and you should be fine, the SSRs should last as long as you own your vehicle.

[pete000]

Nice blend of modern technology !

[Steve_R]

Well, it’s been about a year since I finished my 914 restoration, you can read all about it

HERE.

Everything works perfect except for the electrical problems I’ve been having with the relay board. I spent lots of hours trouble shooting electrical issues with the fuel pump. It turs out that my relay board had some bad connections for the fuel pump relay. After searching this site I discovered that the relay board is truly the weakest link in the 914. I tried to remove the epoxy bedding underneath the board and resolder the connections. This worked for a while but the fuel pump would sometimes stop and kill the engine. I finally figured out that the contacts for the fuel pump relay to the board were causing the problem. This seems like a never ending problem. I could buy another 40 year old used board and have the same problems.
So, to make a long story short, I decided to design a new relay board from scratch. I replaced the original electromechanical relays with industrial solid state relays. They have the same connection labels as the stock relays: 85 & 86 for the coil and 30 & 87 for the switch. The relays are available at most electrical parts dealers like Mouser or Digi-Key if one ever needs to be replace. They also use a lot less power than the original 914 relays. Also, since they are solid state and don’t have any moving parts they will last a lot longer and are more reliable. I also replaced the old ceramic fuse with a modern ATC style fuse and added an LED that illuminates when the fuel pump has power. This is great for trouble shooting fuel pump issues. It comes on for a few seconds after the key is turned on and stays on when the engine is running. Also, I removed the connections and plug for the rear window defroster. I used wires soldered to the connectors eliminating all of the riveted connections. All connections are soldered. To make the board I CNC machined the board out of high density polyethylene plastic.
I built a few extra boards to offset some of the development costs. They are quite labor extensive to build so I don’t plan to mass produce them. PM me if you want one. I would like to get $500.00 each. That includes the board with the solid stare relays. It does not include the voltage regulator. I used a solid state one from Pelican Parts. Both the stock and solid state voltage regulators will work.

Question for you Looks like they are. Are the Solid State Relays are serviceable ?? And is there a warranty?

Mueller is correct, these are not serviceable. Not many digital electrical components are. I'm not sure if the stock 914 ones are. However they are, on this board, easily replaceable. Also, these are not Chinese.

[dangerranger01]

I like this a lot. Did you do your own pcb, or how did you connect all the components together on the backside of the board?

[mr914]

(IMG:style_emoticons/default/agree.gif)
Impressive, got to be in the hundreds of hours in development.

In 10 years of industrial experience, we had hundred of SSR in our industrial ovens and had less than 1/2% fail after 3-5 years of 80% duty cycle at 70% load rating.


In my opinion, those relays will last a very long time

As long as you don't dead short them....

[Geezer914]

That is a work of art worthy of being framed and hung on a wall!!! (IMG:style_emoticons/default/smilie_pokal.gif)

[SirAndy]

What is the diameter of the stock round units? There are mini-ISO relays that are ≈25mm square, maybe remove round covers and put these over? There are smaller ones but then you get into thru hole mount or surface mount assembly and your costs are really going to go up.

(IMG:style_emoticons/default/idea.gif) That would be awesome ..

[Steve_R]

I like this a lot. Did you do your own pcb, or how did you connect all the components together on the backside of the board?

I used wires to make all of the connections. After it was all soldered and tested I filled the back with electrical epoxy potting compound like the original board.

[Mueller]

Mueller is correct, these are not serviceable. Not many digital electrical components are. I'm not sure if the stock 914 ones are. However they are, on this board, easily replaceable. Also, these are not Chinese.

Hi Steve, my apologies if I made it sound like you are using Chinese components!

And thanks for not getting too upset with me replying to your thread!

[Steve_R]

Mueller is correct, these are not serviceable. Not many digital electrical components are. I'm not sure if the stock 914 ones are. However they are, on this board, easily replaceable. Also, these are not Chinese.

Hi Steve, my apologies if I made it sound like you are using Chinese components!

And thanks for not getting too upset with me replying to your thread!

No problem. I never thought you were implying they are Chinese and you brought up a good point.

[jwc914]

This will go very well with my 160 amp alt kit. It is a single wire so no need for regulator. Does it come complete with all relays and does it have a cover? Can u give me a price shipped to san jose, ca 95124

[Steve_R]

This will go very well with my 160 amp alt kit. It is a single wire so no need for regulator. Does it come complete with all relays and does it have a cover? Can u give me a price shipped to san jose, ca 95124

It comes with all of the relays and no cover. I'll pay for the shipping.

Steve

[02loftsmoor]

I would like to get with on the relay board. Wes

[Cairo94507]

I wish you made one of those boards for the Sixes. I definitely would buy one. (IMG:style_emoticons/default/smilie_pokal.gif)

[Kalani]

Well, it’s been about a year since I finished my 914 restoration, you can read all about it

HERE.

Everything works perfect except for the electrical problems I’ve been having with the relay board. I spent lots of hours trouble shooting electrical issues with the fuel pump. It turs out that my relay board had some bad connections for the fuel pump relay. After searching this site I discovered that the relay board is truly the weakest link in the 914. I tried to remove the epoxy bedding underneath the board and resolder the connections. This worked for a while but the fuel pump would sometimes stop and kill the engine. I finally figured out that the contacts for the fuel pump relay to the board were causing the problem. This seems like a never ending problem. I could buy another 40 year old used board and have the same problems.
So, to make a long story short, I decided to design a new relay board from scratch. I replaced the original electromechanical relays with industrial solid state relays. They have the same connection labels as the stock relays: 85 & 86 for the coil and 30 & 87 for the switch. The relays are available at most electrical parts dealers like Mouser or Digi-Key if one ever needs to be replace. They also use a lot less power than the original 914 relays. Also, since they are solid state and don’t have any moving parts they will last a lot longer and are more reliable. I also replaced the old ceramic fuse with a modern ATC style fuse and added an LED that illuminates when the fuel pump has power. This is great for trouble shooting fuel pump issues. It comes on for a few seconds after the key is turned on and stays on when the engine is running. Also, I removed the connections and plug for the rear window defroster. I used wires soldered to the connectors eliminating all of the riveted connections. All connections are soldered. To make the board I CNC machined the board out of high density polyethylene plastic.
I built a few extra boards to offset some of the development costs. They are quite labor extensive to build so I don’t plan to mass produce them. PM me if you want one. I would like to get $500.00 each. That includes the board with the solid stare relays. It does not include the voltage regulator. I used a solid state one from Pelican Parts. Both the stock and solid state voltage regulators will work.

[Kalani]

Hello Steve,

Do you have any left, and has the price point come down ?

I live in so cal so shipping should not be a big deal