Surprises when inspecting the wiring

[Miskatonic]

Well I finally got the old man to come help me with tracing wires to see what condition they all were in. I used the wiring diagram that I believe is linked from this site. I found it with a search but I believe it was hosted here.

Anyway, once we started tracing all the ignition wires we found out a few curious things. It looks like an aftermarket electronic fuel pump was installed, and it is located about 3/4 of the way towards the back. When I charged up the battery and turned the key over the starter did nothing. I scratched my head and tried it again, and then my dad told me to stop because gas was starting to come out of one of the hoses that runs to the carb (intake and carb aren't on there at the moment). So we both began to scratch our heads and wonder what the story is with the starter. Well it appears that whoever owned the car before me had set up either a switch or button to turn over the starter. The hot wire (both wires in this circuit are colored yellow) is connected to the starter where the battery cable is situated, and it runs to one part of the switch which was located just off to the side of the steering column. The other wire runs from the switch to the part of the starter at the bottom right beneath where the battery cable connects, with a small metal piece that slides onto a piece on the starter. So you have a completely separate loop with either a button or toggle switch that opens the circuit and the starter begins to crank like it would with a regular key. The funny thing to me is that the fuel pump is powered by the ignition coil. You have a black wire running off of the positive terminal on the coil, then down to the fuse block, and on the other side of that fuse a red wire runs back out over the firewall and down along the bottom to the fuel pump. So basically at the moment there is no wire running from the coil to the starter.

I'm not sure about the logic behind powering the fuel pump by the coil. Any reason for wiring it this way? Will it keep the fuel pump going as long as the engine is running?

We are in a position to either stick with what we have if the car will run alright, or trying to figure out if there is something wrong with the ignition at the key and if not then wiring it the right way. But then we still have the issue of how to wire the electric pump so that it won't start pumping gas with the key turned. Lol.

Just thought I'd share with you since it was an interesting afternoon.

[GTJIM]

Sounds like you have been 'got' by the dreaded Previous Owner!

Opel ignition switches on the steering column are notorious for getting fried and failing - they kept using the same brain-dead set-up right through into the 1990's ... My 1991 Senator had the same problem switch in it from the Opel factory ( ... and that was in a $US60,000 car!)

Have a search for "Otto Start" which is a relay device marketed by one of our members.

10 to 1 the switch on yours died on the previous owner and what you have is his work-around fix.

As for the electric fuel pump, it does need to be connected to a switched power source back at the fuse block .... and have an oil pressure cutout switch fitted (or some such) to turn it off in case of an accident.
More searching!

HTH

[Miskatonic]

Is there a site for the Otto Start or any pictures or literature on it?

[Lindsay]

http://www.opelgt.com/forums/vbclass...hp?do=ad&id=75

http://www.opelgt.com/forums/opel-ti...tructions.html

[Miskatonic]

Thanks!

Ok now for a quick question. Would someone be so kind as to explain what this device replaces in the ignition system? I'm not too familiar with electrical wiring. Does it replace the function the key has in opening the circuit for the starter when you turn it all the way to the right?

[namba209 (R.I.P.)]

What the "Otto Start" does is take the high amps to operate the starter solenoid away from the ignition switch and keeps the switch from getting fried. A real good idea, as the rest of the electrical system, except the headlights, runs through the ignition switch.

[Miskatonic]

So I could wire this into a separate toggle switch or button for the Starter? If my ignition switch from the key is shot can I still make use of the Otto Start?

I ask this because currently the switch on the steering column (the one you normally start the car with by turning the key) is not wired to the starter now. It's just a separate wire loop that isn't connected to the fuseblock.

[GTJIM]

The "Otto Start" is an enclosed switch or "Relay" which is designed to carry about 40 amps (The poor wee original switch gets somewhere up to 23 amps through it when starting - it is designed for about 5 amps!). The Relay in an Otto Start is activated by a much lower current - about 1 amp.
Basically using a low spec switch to turn on a heavy duty switch.
It the button the "P O" put in your car to start it is heavy duty enough to carry the heavy current, well and good. An Otto Start relay would protect it just like it protects the original key switch. So the answer is: "It depends"

[namba209 (R.I.P.)]

First off, if you do not have a DESTEC wiring schematic for your GT, get one. It is far easier to read than anything else available. With that you can rewire your GT back to close to original. If your ignition switch is trashed, OGTS can refurbish it for you. If you do that, then for sure get an "Otto Start" to be sure your "new" switch operational for years to come. It's all in preventative maintenance.

[SpringGT]

So I could wire this into a separate toggle switch or button for the Starter? If my ignition switch from the key is shot can I still make use of the Otto Start?

I ask this because currently the switch on the steering column (the one you normally start the car with by turning the key) is not wired to the starter now. It's just a separate wire loop that isn't connected to the fuseblock.

As built by Opel, the ignition switch on the column is asked to carry the full current required to engage the starter solenoid. Over time, the switch gets to where it will no longer carry the necessary current load and your starter will no longer work.

The Ottostart kit furnishes a new relay (switch) that handles the heavy current-carrying duties formerly performed by the column switch and the relay is wired so that it is controlled by the column switch.

Most of the time your existing stock switch is still able to carry the small amount of current required to operate the Ottostart relay, so when you get your Ottostart, hook up your column switch and see if it will work. I put my relay in over 15 years ago and it still works fine with my old column switch.

If your stock column switch will not work, for a reasonable fee,Opel GT Source can rebuild it so that it does.
HTH
Bob

[Miskatonic]

I appreciate the explanation.

[Lindsay]

First off, if you do not have a DESTEC wiring schematic for your GT, get one. It is far easier to read than anything else available. With that you can rewire your GT back to close to original. If your ignition switch is trashed, OGTS can refurbish it for you. If you do that, then for sure get an "Otto Start" to be sure your "new" switch operational for years to come. It's all in preventative maintenance.

Can't hurt to purchase Factory Service Manual (usually on eBay) for separate illustrations on wiring circuits, but I use DESTEC wiring diagram most of the time for quick reference. You can PM DESTEC (JJ Wheatley) from this site to inquire (less than $30.00).

Wiring diagrams for GT and Manta:
Opel Association of North America

Search "Ignition Relays" and "Otto Start" for more information:
http://www.opelgt.com/forums/1a-star...t-starter.html

[Miskatonic]

Here's the wiring diagrams I used. These ones are a bit different in that they break things into sections so you don't have a bunch of overlapping wires to deal with that might not be part of a certain section, say ignition for instance.

http://opelgt.com/tech/artman2/uploa...g_diagrams.pdf

[Lindsay]

Here's the wiring diagrams I used. These ones are a bit different in that they break things into sections so you don't have a bunch of overlapping wires to deal with that might not be part of a certain section, say ignition for instance.

I saved those wiring diagrams to my computer. Easier to print out, rather than grease-up the ones in the manual. THANKS!

[baronbors]

Speaking of OTTO Starts-- since I never had a starter switch in my car when I bought it (had to hot wire it ) I had been using the generic lawnmower switch purchased from Wallyworld for $9. I had to replace them about every 6 months or so due to burn out.. Since installing my OTTO Start a year and a half ago, have not replaced it once and still going strong. Thanks Otto.