Circuit Breaker Auto lite 4101

[Tom Skinner]

Dear Forum,

A plea for electrical help - please - anyone - after 20 hours of playing with this. Its getting to be to much fun.

I ran into a vibrating problem after I replaced my Transmission Harness.

I'm working on a 1948 Chrysler Royal with Fluid Drive.

First I thought I had put the Throttle Spring on wrong hence a Springy vibrating noise upon excelleration between 14-20 mph. I then replaced the Transmission Relay Switch even though it passed all electrical tests in the Service Manual. Same noise.

I started to bump/thump around with my finger under the Transmission Relay Selenoid is another box this box is labeled Auto Lite 4101 It has a wire going to the ground on the Transmission Relay Seleniod Box. I assume its the circuit breaker there is where the vibrating points noise came from. I cleaned the points and re-installed - same vibrating points inside between 14-20mph.

Does anyone know if this is related to the Governor Points not opening soon enough at the Transmission?

The Governor passed electrical tests for upshift however I have not opened it to look inside. I am stumped. Has anyone had a problem like this before? If so please let me know how to fix it. The vibrating Points in that box only last for 5 mph mostly while its under a load not coasting down hill or level pulling. I am electrically challenged to that I admit.This is my second 1948 Chrysler and I have never had this problem before. Ammeter shows steady charging and car runs great otherwise. Shifting is smooth everything otherwise is normal.

Tom Skinner

Huntersville, NC

[Tom Skinner]

Fellows,

I forgot the preffix on that AutoLite Box it is HRM 4101

I believe it is a circuit breaker. If that is true some kind of electrical vibration is causing those points to dance loudly for a short period upon the upshift.

[alan32433]

Tom,

Are you sure it's a transmission electrical problem at all? If the transmission is shifting normally maybe the noise is something else. For the noise and conditions you are describing, the first thought that came to mind is the voltage regulator. Inside the regulator there are actually 3 components, a circuit breaker, a current regulator and a voltage regulator. The voltage regulator consists of a set of points that vibrate during operation. How the voltage regulator operates in the circuit is of course highly depended on engine RPM. Since the regulator unit is mounted very close to the transmission kick-down relay, it would be easy to mistake where the noise is coming from.

I've seen regulators that were really noisy at RPM when the regulator was having to limit the voltage from the generator. At lower RPM, idle for instance, the generators output is not high enough to force regulation hence no noise.

If indeed the noise is related to the transmission circuits, it seems to me like the kick-down relay might be at fault. The kick-down relay is controlled by the governor and should cause a shift at around 12-14 MPH. If the kick-down relay has bad points, has weak springs, or has a weak coil (closes the points), then that could cause the points to vibrate as they change condition from closed to open or visa-versa. Last but not least, the same kind of problem with the governor could cause the kick-down to vibrate. You can take the top off the governor and clean those points and check for a weak spring. Don't file the points because they are silver plated, filing will ruin them.

[Frank M.]

Hi Tom. My 46-48 Chryslers use the HRM 4102 Kickdown Relay I believe. I think the HRM 4101 is for the earlier Trans. Let me look in my Aoto-lite books for assurance Frank M.

[alan32433]

Fellows,

I forgot the preffix on that AutoLite Box it is HRM 4101

I believe it is a circuit breaker. If that is true some kind of electrical vibration is causing those points to dance loudly for a short period upon the upshift.

Tom, HRM 4101 is your kick down relay. It has a fuse but no internal circuit breaker.

[Tom Skinner]

Dear Alan32433, and Frank M,

Thank You very much for the information.

I was ignorant as to what it was now I know its a kickdown switch.

Frank Thank You for looking the part number up for me.

Alan, it might be the Governor Points I'll go there next. and use a soft silver cleaner on a cloth to clean them. I have another Voltage regulator but after thumping around with my fingers I'm sure that noise is coming out of that switch. On another thought wouldn't the Ammeter show problems if it was the Voltage Regulator? It shows a steady slight charging as it should with no jumping needle in shifting patterns.

On my last test drive I noticed downshifting was delayed - not consistent.

Tom

[alan32433]

Tom, another thing to check. Make sure your kick-down relay has at least 6 volts to the terminal labeled BAT. The governor actually supplies a ground to the circuit at the terminal labeled TH, but if the voltage is low to the BAT terminal, your coil will not firmly set the points. Voltage comes to the kick-down switch BAT terminal from the negative (hot) side of your ignition coil, which of course comes from your ignition switch.

Check the voltage with the engine running. In order to check for a true 6 volts, the circuit has to be under a load.

[Frank M.]

Tom 46-48 Chrysler M-5 Trans uses a HRM 4102 Kickdown Relay. That could be your problem. Chrysler No. is 1113 084. Without looking further--Im pretty sure the HRM 4101 goes on pre war cars. How that got on your car would be interesting to know. Was it there when you got it? Frank M.

[Tom Skinner]

I guess my last stupid question would be where in the world would I find a Auto Lite HRM 4101 Kick Down Switch? At a Salvage yard?

Tom

[Tom Skinner]

Frank,

Yes it was on my car when I got it in 2007 the car had 52,245 original miles on it.

[Tom Skinner]

Dear Alan,

when you say undera load do you mean reveing the motor or driving it with a voltmeter and long leads on it taking the reading?

[Frank M.]

Tom Since I have three 46-48 Chryslers--I picked up a few extra HRM 4102

Relays If you wany one , let me know. I havent sold any,but I think I have enough for my cars to let one loose. Frank M.

[alan32433]

You just need to have the engine running. If everything is off, the circuit is not pulling any amps. Under no load, it's easy to provide 6 volts. So under no load you may have 6V, under load, the volts could drop to 4 for instance.

After further thought, I would make sure my voltage was good before I pulled the top off the governor. Easiest stuff first, I always get that wrong.

Far as your regulator question, the regulator would still be doing its job, just making a lot of noise doing it. That would be indicative of worn out points, springs or even the mechanical pivot.

But for sure I think you are right, it's most likely your kick-down relay or wiring circuitry.

[alan32433]

Frank and Tom,

I looked at your profiles, NICE cars! Mine will look like that one day, I'm just really slow. Could be because I'm in here messing around on the computer and not working on it?

[Tom Skinner]

Dear Alan and Frank,

Thanks I will have lunch and check for the six volts at the kickdown first. I'll get back on in a little while.

Frank Thank You for your generous offer. I will get back with you on it a little later with more information.

Thanks again!!!!!!

Tom Skinner

Huntersville, NC

[Frank M.]

Alan and Tom Wouldnt it be best to check if he has the right relay first. If its a 46-46 Chrysler The Relay should be a HRM 4102. The HRM4101 will never be right. All 3 of my cars are using the 4102, and thats what the book calls for.

Frank M.

[alan32433]

Frank you are right, I would definately want to put the correct relay in it, even if he found a wiring problem. My 48 DeSoto has a HRM 4102 also.

Frank your car is really really nice!

[Gary Manes]

As noted above the HRM 4102 is the correct breaker number. I have a couple of HRM 4101's I bought without double checking my parts book because the price on E-bay was so good.

For reference, you may wish to copy the transmission manuals that are on the Imperial web site. I did that when we were originally working on my 1948 New Yorker. They are pretty good. Now, however, my tranny is doing something not mentioned in the books--it will shift into neutral while cruising around town in the 25mph to 35mph range--not down or up--neutral. When I tap the accelerator it shifts back into "hi."

All just part of the "fun" of owning an oldie. Which is why I do not plan to keep the fluid drive in my 1948 Desoto.

Good luck with your problem.

[Frank M.]

Gary--just a shot,but check your fluid level. Frank M.

[alan32433]

Good idea Frank. If the fluid level is correct, it would be a good idea to check the transmission pump pressure (if you have a gauge and a way to attach it). There's a test plug on the side of the transmission, it should read 50 lbs. If the pressure drops too low at any time while in gear, the direct speed piston will release and the shift arm will move the transmission out of gear into neutral.

[Tom Skinner]

Dear Frank and Alan,

The plot Thickens. I had lunch then...............

I tested the Kickdown at the BAT Terminal and it showed a steady 8 Volts.

I Ran all Tests at the Relay and it passed all the tests. The Engine even stalled when a test light was hooked between the SOL and Ground and I Grounded the INT terminal. It now is either the Voltage Regulator or the Governor Points are dirty. I have an extra Voltage regulator shall I put it on first and see what happens?

Tom

[Tom Skinner]

Frank,

I sent an email to you about the HRM 4102 Switch, I just don't understand how after tripple checking everything why it would start making a noise after I changed out the Transmission Harness???? I got the harness from RIWire and everything wired up right to the directions first time right. I ran tests all along and can only figure its a wrong Kickdown Switch bad Voltage Regulator or Dirty Points at the Governor. I'll change out the Voltage Regulator and get back on later.

Tom

[alan32433]

Tom, do you have an 8 volt battery installed, just curious. If your battery is a 6V, your regulator is overcharging.

It could still be your kick-down relay making noise. Frank is right, you should probably replace your relay with the correct 4102. It seems to me like this is the most likely culprit.

If you don't want to wait for a relay you can check the governor. If you do decide to check it, you need to unscrew if from the tranny and do the work on a bench. You might have to make a gasket, they usually get damaged when taking the top off. They are known to be extremely reliable.

Checking the voltage regulator would depend on how sure you are the noise is coming from the kick-down (or not). Regulator is pretty easy to change just to eliminate it.

[Tom Skinner]

Dear Alan,

My battery is a 6 Volt so as you say the Voltage regulator is probably over-charging as I know my VoltMeter is accurate its an old needle type. Set at DC and 10 Volt settings all my readings have been at 8 Volts when running and just over 6 Volts with the Engine turned off.

You my friend are a genius. Voltage Regulator here I come!

I'm still going to try to get a HRM4102 Kickdown though

Tom

[Frank M.]

Just got back guys. Been to Great Grandaughters 1st Birthday party. Yes-----Im

old enough for a G-Grankid. Gary--the pumps on these trannys are very good.In fact Ive never seen one go bad. I had a similar prob with a freinds car that would shift down on a downhill slant. The fluid would go forward and the pump coulnt pick it up. That was due to a low level. Maybe not the cure,but easy fix if thats it. Frank M.