Red Hot Ignition Switch

[JCoop]

Driving home 70 miles on the GT40 last night, I got home and almost burned my fingers turning off the ignition switch. I had the A/C on throughout the 1.2 hour drive, headlights on, both radiator fans on with the overide switch, and my cell phone on the hands-off device plugged in to the accy plug hooked up to the ign-on terminal on the switch.
Does anyone kn ow if The CAV headlights are on relays?

 

[Ron Earp]

Sounds like you've got a simple electrical system that isn't using a relay somewhere, or else you have a short. I imagine it is the former and for some reason your fans, AC compressor clutch, or headlights is sourcing from your ignition switch. Not something you want to be happening. Need to trace that out and find which one is pulling from the switch as the switch probably won't like that sort of heat/draw forever.

Ron

 

[40 Bud]

I think Ron is dead on. The old GTD's ran everything thru the ignition switch. The only relay on the car was on the A/C circuit. Add some relays and power all of your stuff from the relays and just use the ign. switch for power to the relays.

 

[Ron Earp]

I think Ron is dead on. The old GTD's ran everything thru the ignition switch. The only relay on the car was on the A/C circuit. Add some relays and power all of your stuff from the relays and just use the ign. switch for power to the relays.

You might be more accurate in your statement than you realize. I think that the early CAVs were GTDs built under license for all intensive purposes and might have the exact same harness and layout. I assume that changed with the mono cars and restructuring, but it'd be worth a check for anyone running a car, regardless of make.

R

 

[Pat]

All are correct, there is just too much amperage routed through the stock ignition switch on the older CAVs. There is a relay kit that should be added to your ignition switch to resolve the problems. I think the factory or your dealer should have it (Call Roy at VIP Classics (619) 232-6864). If you can't find it, PM me and I'll e-mail you the schematics for the fix.

 

[JCoop]

Thanks all...
Veek, I appreciate the offer. Bob Childress saw my post while travelling and has kindly e-mailed me his schematics and fixes for this particular problem.

I will report results...

 

[Bob Childress]

Ray, -- Veek was the original person to give me the schematics and advice almost 2 years ago. I really just passed the A/C schematics on to you.

Pat, -- I noticed in your post that you may have the schematics for the ignition switch relay upgrade. My car already had the relay added but I don’t have the wiring diagram for that fix. If you have the schematic for the ignition switch relay please email a copy to me if you will. Ray may also need a copy too. And thanks.

This just goes to prove that what goes around, comes around. This is a great example of why all CAV owners need to know each other so everyone can get whatever information and help they need from other owners over the next years. Any CAV owner who reads this should sign up on Cliff’s CAV registry which is a very good deal for all of us. I appreciate the time and effort he is putting in to do it.

Bob

 

[Howard Jones]

Please send me a email copy of the print in question. I would love to compare it to the GTD electrical drawing print. I will post my resulting impressions. This might be of some help to some GTD guys.

 

[dennis jones]

hot ignition

I just hooked my A/C unit up and found my switch also very hot. Lucky I stumbled upon this thread. could someone forward me the email in question so I can solve the problem. thanks in advance.

GTD 347 webers and having lots of fun now I have A/c!!!

 

[Howard Jones]

Now that's something! My name is Howard DENNIS Jones. I have a GTD and I live on the west coast. What is the probability of another Dennis Jones with a GTD on the east coast.

Off the top of my head I would use the 12+ going to the clutch coil from the key switch through the AC on switch to energise a relay instead. Then route a new power source wire from the main +12V buss at the fuse panel through a proper value fuse to the switched contacts (normally open) on the new relay. Then from the other side of the normally open relay contacts to the clutch coil.

This will limit current through the key switch to the small amount it takes to energize the relay. The much larger current to keep the AC clutch pulled in will be applied through the relay contacts.

In general the entire car should be laid out like this as far as things like lights, MSD box, radiator fans, oil pumps, or other high current loads.

I wish I had done my own wiring on my car when I built it. It was clear that the stock GTD electrical system was poorly designed but like most people I was in a hurry to build the car and just used the GTD supplied kit wire looms.

 

[Mike Christian]

doppleganger ?