Quick wiring question

E-Type
#1

I need a source of a wire that is “hot” only when the ignition in on, under the bonnet and as close to the front of the car as possible. I’m wiring in a temperature probe (hayden switch) for an electric fan setup that needs both a constant power wire (the terminal that the positive battery terminal connect to) and a source of ignition on only power.

Right now, I’m planning on having this relay located on or near the frame section between the drivers side shock absorber and the battery and would like to find the closest ignition on wire possible. Any suggestions?

#2

If you want a wire that is protected by a fuse you need a Green wire. If you want one that is not fused you need a White one. Both Green and White wires are only hot when the ignition is turned on.

#3

The relay itself has two 25 amp fuses on it for the main power (red wire) and for this ignition only wire, that seems sufficient as far as fuses are concerned. Now on to find a green or white wire…

#4

Coil feed?..

#5

No, you can’t use the coil feed because the coil impulse drives the tach. Using the feed for power will really produce some interesting results. The simple answer to your question is to use the power feed for the fans. Do I want to know how the constant power is wired?

I know I’ll regret this, but what are you doing now? The Hayden switch doesn’t do anything that you really need done.

#6

The plan was to wire this fused line directly to the terminal that gets positive power from the battery.

#7

Right. Then use the fan power wire for your switched connection.

So What exactly are you trying to accomplish?

#8

New electric fan that is controlled via the hayden switch with a temp probe, not the otter switch. It needs full time power (power terminal), ignition power (needed for temp settings for activating fan), ground, feed from AC unit to activate when AC turned on, feeds to fan power and ground.

I have it all routed and laid out, just needed ignition power. PO hacked the old system with three fans, his own relay, and mislabeled wiring. I’m trying to sort it all out with color appropriate wiring. I need to find the original fan power wiring because he did some unusual things. Using the correct wiring for the fans is a far better idea, once I locate them.

#9

Wasn’t this where your story started?
All you need to do is find the green wire that fed power to the original fan system, it’s there somewhere. That’s your switched 12V supply. It will only be used to drive the relays, your battery connection is what actually powers the fan. You had some decent hardware in there to begin with, was nothing salvageable?

#10

My fan setup has always been a nightmare. When the after market AC system was installed apparently the car overheated, so the PO zip tied an electric fan to the front nose of the car (the grating) and wired a toggle switch under the dash. One had to remember to turn it on when turning on the AC.

At first, I didn’t like the kludge of the toggle switch and swapped the wiring to the unused defroster switch on the panel. After further thought, I ripped it all out and started anew with tracing wires, removing the electric fan and ultimately the factory twin fans in favor of an electric fan activated by the hayden switch.

I will be probing for the original wiring tomorrow, you’re right it likely all still there, but many connections have been wrapped up in electrical tape and I get a surprise each time I unwrap something to figure out what it was originally used for. I’ve found wiring that has been spliced with different colored wires twice withing three feet of each other. White spliced to blue then a few feet later spliced to yellow…I’m fixing all that as I find it.

#11

I have a sneaking suspicion about the AC on this car. The battery splash panel has three original looking relays (horn, alternator, and AC) but the AC system is clearly aftermarket. I suspect somewhere in the last 51 years, the car may have been built with factory AC, then had it torn out for some reason, then replaced by an aftermarket system.

I suspect this because of the relays, and the spaghetti wiring that I am fixing as I find it. There does seem to be hints of factory air here and there, but the presence of the aftermarket system has masked it until now.

Another reason I suspect the car had factory air is that as I understand it, the ignition key switch was mounted on the AC control panel. In my car from day one, the key was held by a home made bracket that was loosely bolted to the steering column. From this forum, I found out that for Series 1.5 and early Series 2 cars without factory air. the switch was held on a figure 8 style bracket that was attached to the steering column.

Searching for that part was inconclusive @NaplesGuy showed me his and that it was a nightmare to find. Luckily after several months I found one in the UK but I wasn’t able to convince the seller in the UK to sell me the one part he had, but it turns out he’s a fabricator and after getting so many requests for the part in both the US and the UK, he decided to fabricate them himself. I managed to make a trade with him for a part he needed for measurements to send me his first one. The are due to be back from powdercoating this week and I hope to install it over the next couple of weeks, once I receive it.

#12

It’s best to cut away the mess. I’m sure there’s a live power feed in there somewhere.

#13

Bob
Peel back the banana on the drivers lower frame rail side
The original green , key hot wire from the original fan is there some where down low where the picture frame meets up
Good luck call me later
If you need more help
Gtjoey1314

#14

For those of you who couldn’t sleep last night due to the suspense of wondering if I was going to find a source of power tied to the ignition, please rest comfortably tonight, it has been found.

Under a layer of electrical tape, with the cloth wring cover/color stripped off, I found a bullet pressed into a rubber connector (female) that wasn’t connected to anything. Once I put my multi-meter on it and turned the key, voltage appeared! I am not set with all the original locations to wire the new hayden switch to for a new electric fan.

#15

Great job Bob!
As you peel back the harnesses and the butcher jobs , it will all come together.
IMHO As you also put that modern aluminum Rad and fans and leave ALL the old relays and otter switches behind it will be so much easier to maintain and follow in the future.
Most understand on this forum, The original components werent that bad back in the day, its when hacks think they reinvented the wheel is when it all goes to pieces.
Good luck.
GTJOEY1314

#16

Which brings us back to the Hayden switch. This is actually a repeat of the wiring scheme used with your aftermarket fan setup. What problem are you trying to solve?