1947 Starting Voltage Issue

[Decoda]

This problem started after the car was sitting for a few weeks. When I press the starter button nothing happens. When I connect the starter relay directly to the battery, the solenoid engages and the starter turns the engine over so I know they are good. After some troubleshooting I measure only 4.2 volts across the stater relay when I press the stater button. I am losing voltage somewhere but I can't  figure where the voltage drop is coming from. Any ideas?? 

[Bobby B]

Robert,
Hi. It's a pretty simple system. Assuming all you cables are good, tight, and grounded properly....When the ignition switch is in the "on" position, you should have Voltage coming from your ignition switch over to your Starter Pushbutton. From there it's in series with the Neutral Safety Switch located on your steering column (if you have a Hydra-Matic Transmission). From there it goes down to your starter solenoid. Just isolate and trace out all your wiring. It could be dirty/faulty contacts on one of these switches from sitting or loose screws on either the Starter Pushbutton or the Neutral Safety Switch, etc. Simple circuit to troubleshoot. Hope this helps...
                                                                                                       Bobby

[bcroe]

This a basic electrical troubleshooting problem.  Tie one meter lead to
battery ground, then start walking the other lead from the battery hot
terminal, down the path to the starter relay.  Somewhere you will note
a big loss of voltage.  You have just walked by the fault, get it fixed. 

Bruce Roe

[Decoda]

Thanks for the repies. I'll start troubleshooting and let you know what I find.

[Decoda]

After much troubleshooting, I found the wire leading to the neutral safety switch was shorting to the wire for the temperature sending unit. Both wires come out of the same harness along the firewall. On both wires the insulation had fallen off and they were shorting to each other.

Any recommendations on who can supply new wiring harness for the engine bay?

Bob

[bcroe]

Thanks for the report.  If all the wiring is marginal, guess replacing
the harness would be a good idea.  if you can't find a harness, it
might be practical to make your own.  Use wire of the proper gauge
(larger is OK), with insulation rated for this kind of service.  However
almost all wire today uses plastic, not cloth insulation. 

I have made a few using the original connectors and heat shrink. 
good luck, Bruce Roe

[C Gorgas]

I have used Rhode Island Wiring Services, Inc located in Kingston, Rhode Island. Their work is an exact match to what you have on the car...color codes and all and no problems installing because they are exact. Telephone 401-789-1955. I have used them for my '40 LaSalle and my '41 Cadillac. Chet25441

[DaveZ]

I got a harness form Rhode Island. Excellent work and service.

[bcroe]

RI sounds like a great resource, for cars before 1960.  With modern
equipment they could probably make up a harness and ship it in next
to no time.  Their inventory is so extensive, I would expect most of
it exists as electronic files.  Please report on the results.  Bruce Roe