Wiper motor using relays - another question

[Roycape]

Hi all, I've read the threads on upgrading the performance of the wiper motor ie. using the step up converter as well as using the relays. The one point I couldn't seem to find in using relays was which wires to use for the relays trigger pin #86.

I have an '81 Spider and I was wonderiing if I should use the "Slow" grey wire from the switch as the trigger to the one relay #86 pin and "Fast" blue wire from the switch to the #86 pin on the other relay. There are six wires to the wiper motor and I'm unsure which ones will cause power to go directly to the wiper motor from the new source.

Thanks for your help.

[dinghyguy]

Hi,

This is how i did it, not saying it is the only way, but it works for me. I did almost all the wiring in the engine compartment which is untidy, but was quick to do. I put relays under the cover where the wiper motor is, again, easy but not elegant.



hope it helps.
Dinghyguy in the tiny garage

[Roycape]

Thanks for the response Dinghyguy. That's exactly what I wanted to know. I won't go to a 6 pin connector but will just make a new circuit for the "slow" and "fast" wire connectors from the switch and to the wiper motor.

Did you use 14 gauge wire? Also, do the relays only provide power when in the "slow" or "fast" position as described. What about when the switch is in intermittent position? Does the power flow through the normal switches then? Either way, thanks for the input.

On a side note, I have another issue. I bench tested the motor and it worked. When I opened it up to grease the shaft, the contact arm inside fell out. I was rusted through. I'll have to solder it back up and hope it works properly. Either way I have a newer 6 wire working wiper motor that I can use.

Thanks again. Lots of snow in T.O. and major deep freeze. Enjoy the rainy weather in Vancouver.
Roy

[dinghyguy]

Hi Roy,

I used the same gauge wire as the existing, which is 14 i think.
On mine the intermittent is actually a fiat installed timer system that just turns the normal system on and off (located under the glovebox with the other fiat relays). Thus the system as i installed it does not care about the intermittent function and thus works fine.

grey and +7 C today but no snow yet this year in Vancouver, glad you are freezing in TO. Was out fiating in the sun last weekend.
cheers
dinghyguy

[Turbofiat124]

Are you talking about me?

https://www.youtube.com/watch?v=gRR5HO2H8_c&t=11s

I tried using relays on my 131 and it worked to some extent but I think the step up converter is the way to go. It's allot easier to wire up (just 2 wires). An electrician told me bumping the voltage up 1 to 2 volts was actually easier on the motor because it didn't pull as many amps.

I mounted mine under the cowl.



BTW, that's a Bosch wiper motor from a VW Rabbit. Which is one step above the Marelli motor.

1) Disconnect the wire going to the wiper switch (after the fuse) from the fuse box. I think this wire is yellow or yellow w/black tracer.
2) Connect a wire along with a 10 amp circuit breaker to the input wire on the step up converter and plug this into the fuse box .
3) Run a wire from the output of the converter and connect it to the wire that was disconnected from the fuse box.

The reason for the circuit breaker is if you accidentally leave the wipers on before shutting the engine off then you go back to restart the engine, due to the difference between battery voltage (12.6) and alternator voltage (~13.6 to 14.3) there is a huge current spike. This can blow the fuse. The other thing is if the heater is on which shares the same circuit can also blow the fuse if it's on. But particularly on cold mornings the wiper motor struggles a bit.

I can't remember the exact readings but with the engine running the current draw of the wiper motor was around 3 amps. Without the engine running was over 10 amps. That's a huge current spike! That somewhat breaks Ohm's law!

Since I did the "brown wire fix", I have not had any issues with tripping this circuit breaker. Either with the heater fan running with the wipers or running the wipers with the engine not running.

Here is the 10 amp circuit breaker. I could not find anything below 20 amps at any of the local auto part stores. You use an ATO type in-line fuse then plug the circuit breaker into the holder where the fuse would have went.

https://www.amazon.com/Auto-Reset-Blade ... B00NVJ0LEC

[DieselSpider]

Even if I went with a step up transformer I would still use a relay to get the load off the ignition switch. My current thinking is to eventually change to having a main power relay between the ignition switch and the fuse box so the only load on the ignition switch will be just the coil on the relay. There is just too much of a load being carried by the ignition switch on these cars especially now that the switches on many are 40+ years old.

[spider2081]

My current thinking is to eventually change to having a main power relay between the ignition switch and the fuse box

Most Fiat 124's have 2 wires supplying power to the ignition switch. The brown wire originates at the starter solenoid and connects to terminal 30 of the ignition switch. The black wire originates at the alternator output post and connects to terminal 30/1 of the ignition switch. I think one would need at least 2 relays to bypass the ignition switch contacts.
The steering column switches are another failure point in the 124 electrical systems. The headlight and the wiper relay kits sold by the vendors by pass the ignition switch and steering column switch contacts. Thus protecting both troublesome original switches.

[DieselSpider]

My current thinking is to eventually change to having a main power relay between the ignition switch and the fuse box

Most Fiat 124's have 2 wires supplying power to the ignition switch. The brown wire originates at the starter solenoid and connects to terminal 30 of the ignition switch. The black wire originates at the alternator output post and connects to terminal 30/1 of the ignition switch. I think one would need at least 2 relays to bypass the ignition switch contacts.
The steering column switches are another failure point in the 124 electrical systems. The headlight and the wiper relay kits sold by the vendors by pass the ignition switch and steering column switch contacts. Thus protecting both troublesome original switches.

It would be the output to the fuse box and unprotected circuits that would have the relay on them and not the feeds. I would put in a new 10 or 8 gauge feed line to provide the power to the relays input terminal and just use the ignition switches output to activate the relay. That way the only load on the ignition switches run circuit would be the coil on the relay. Most of the cars were delivered until about 1978/79 without the brown wire which many owners then added after they bought the cars.

This really came to a head when Fiat changed to spade connectors on the ignition switch around 1972/72 and the Famous Brown Wire Fix came to be.

See The Famous "Brown Wire" Fix written by Ken Dickson of MiraFiori:
https://www.mirafiori.com/faq/content/bwfix/bwfix.htm

[spider2081]

To the best of my knowledge the Fiat 850 and 124 ignition switches all have spade connectors. I also think they all have a black and a brown feed wire. The brown wire fix entails adding a new brown wire that parallels the original Brown wire. What it accomplishes is 1. increases current carrying capacity. 2. bypasses a factory connector installed between the starter solenoid's battery terminal and the ignition switch terminal 30. The ignition switch has 2 terminal 30's that feed the same internal contact inside the ignition switch. The brown wire fix is not using unused switch contacts inside the ignition switch as some people suggest.
There are 3 generations of Sipea ignition switches. The very early switches are very similar to the Lada switches currently sold by some vendors. The later switches have a pigtail and connector. The wires on these switches are soldered to the ignition switches spade connectors.
Each of the feed wires to the ignition switch feeds a separate set of contacts for the "hot in start and run" circuits in the car. These 2 outputs could be combined to a single output by using a single relay. However the safety in numbers provided by the redundancy of 2 circuits is lost. Yes twin engine airplanes have more engine failures than single engine airplanes. However when a twin engine airplane loses an engine it still has one left.

[Turbofiat124]

Adding relays for the headlights and fog lights are a good idea. These can pull up to 8 amps each or a total of 16 amps . And the older the car, the more resistance in the system which pulls even more current. I've measured current draw on the headlights and each bulb can be right at the brink (8 amps). I can see how these would cause a load on the ignition, headlight and dip switches.

If you go by ohms law by stepping up the voltage to a device like a motor reduces the current draw.

Bulbs are a different story. They are not as forgiving when it come to applying a higher voltage and can blow.

Remember current not voltage is what produces heat which is the enemy on switches and wiring .

I've just been very pleased with a result. I'm probably not actually sending 15 volts to the motor but probably closer to 14 volts when you take into the account of all the voltage drops across the switches and connectors.

I never bothered to measure voltage directly at the motor.