Ignition Switch Wires hot to the touch

[BakersChoice]

Hello all, I'm having a small issue with the 81, but want to nip it in the butt before anything worse happens. The blue wire and the black wire on the back of my ignition switch are very hot to the touch. Like burn your finger hot. Some of the insulation around the blue connector was melted previously, so I'm thinking that's causing some resistance. But I don't think it would cause so much resistance as to make the wire itself get really warm like that.

Has anyone ran into this before and have any ideas? Thanks.

[azruss]

Sounds like you've had the problem before. Heat can be generated by over amps in the wire...either through a short or an accessory that is drawing too much current, or a bad or dirty connection. If you can get a hold of an induction ammeter, you can see if the lines are drawing too much amps. You can also feel downstream and see if each wire is hot along its entire length. If not, then you have a bad connection point that is creating heat. If you suspect a bad accessory, you can unplug them or pull fuses to see if that stops the heat.

[RRoller123]

Are these wires soldered to the back of the ignition switch, or installed with Faston type connectors?

If not soldered, check how loose the connections are on the back of the ignition switch. They should not just pull right off with minimal force (as mine did).

These connections can very easily become loose through age. The Jack side of the connector can be tightened up by slightly bending in the curved wings, making the connection much tighter.

[Tobi]

A headlight relay kit helped on my car and I have finally decent ligths.

[BakersChoice]

Thanks for all the replys. The wire is hot all the way through, past the c31 connector even so it's something with the circuitry.

It's been raining here a lot so I've been having to use the headlights, maybe that's what's pulling hard on that circuit. I do have access to a multi-meter so I will check the amperage and see

[BakersChoice]

The wire ran cool yesterday and I didn't have the headlights on, so I'm thinking that's what creating too much resistance.

On another note, my car was driving fine today, I pull in to my friends garage to set the ignition timing, set it just fine, then went to go start the car and it sparked once and that was it. I cleaned all of the connectors at the coil, tested the resistance on the coil and it's fine and still I only get 1 spark before it won't spark anymore. If I wait 5 min I can try to crank it again and I'll get another attempt at firing out of the car.

[BakersChoice]

Must've shorted out the Ignition Control Module when I was cleaning the contacts, I'm usually good about disconnecting the battery too...oh well, new Ignition Control Module installed. The tach was bouncing all over the place and it was misfiring, but that also had to do with the wiring on the coil touching each other when they shouldn't have been. Now that the ignition timing is set it runs great, a lot more power and throttle response!

[spider2081]

Do you know if you have a stock Fiat ignition switch??

Using the Fiat wire diagram for an original ignition switch.
The black wire should be on terminal 30/1 of the ignition switch and is a "hot all the time" feed to the switch. When the ignition switch is in the "run or start" positions it is connected to the Pink wire feeding fuse A and the coil.
The blue wire with a black trace should be soldered to terminal "INT" on the ignition switch. At C31 it connects to a light blue wire with red trace that then goes to the battery warning light. Also at C31 the same terminal connects a light blue wire to the headlight switch to power the headlights and running lights when the headlight switch is in the headlight on position. What my wire diagram shows is the black wire and the blue wire are in different circuits and if they are both getting hot when your headlights are turned on someone may have missed wired your car.

[BakersChoice]

Unfortunately I do not have a stock ignition switch, I believe it's one of the lada ones off of autoricambi. The blue wire is piggy-backed onto the pink on the back of the ignition switch

Someone mis-wiring the headlights wouldn't surprise me, the PO had the radiator fan hooked up like a Chevy (i.e the fan was always grounded and when the car reached 190 the positive would then make it to the fan)

[RRoller123]

I also have the Lada after market ignition switch, on my 80FI, wired thus:



here's what the manual says:



Pete

[spider2081]

I also have the Lada after market ignition switch, on my 80FI, wired thus:

I believe this is correct.

The Lada replacement switch is manufactured different internally than the original Sipea Switch. The original switch has 2 separate switches and voltage sources that are used in the "run" position of the switch. The Lada has only one so the wires have to be doubled up on the switch contacts.
For FI cars:
On the original switch terminal 30 (brown wire) and terminal 30/1 (black wire) are voltage into the separate internal switches. In the start position terminal 30 makes with terminal 50 (red wire) to power the starter solenoid. In the "run" position terminal 30 makes with the (int) terminal supplying power to the headlight switch and the battery warning light. Also in the "run" position terminal 30/1 (black wire)makes with terminal 15/54 (pink wire) supplying power to the ignition and Fuse 1

Being the Lada switch passes all the cars switched current through one set of contacts instead of 2 like the original switch I would not be surprised if the switch operates hotter than the original.

[djape1977]

lada has relays in ignition circuit unlike fiat, therefore it doesn't need double set of contacts to avoid overheating. install relays into circuit and it won't overheat and melt

[BakersChoice]

Yep this is the 3rd switch I've installed so I'm getting used to wiring it correctly . Just FYI I bought an ignition switch from Mr. Fiat on ebay and to keep it to the point the ignition switch was garbage. The channel on the back wasn't etched in enough to keep the metal ring and plastic circuit in place so it would just pop out when I turned the key.

I've since installed headlight relays and the wires stay a lot cooler. I'm sure if I had the stock switch it wouldn't be an issue but the lights are also much brighter so that's a plus.