Electrical Issue where to start

[kingkonger708]

Yesterday I started my 62 Scout 80 and while it was idling I turned on the lights. They didn't come on at first so I played with them a little untili they flicked on. I didn't wait for it to warm up and it stalled on me while I was backing up. When I turned the key in the ignition to restart I got nothing. No sound no nothing. With the key turned to on the lights still work as well as the guage lights.

Some history - it looks like the po rewired my 80 (has yellow, black, red wires not just the standard green wires that were on original 80's). The wiring looks to be in reasonable condition. More background - to get the radio to work I need to move the key in the ignition a fraction toward off for the rado to get juice, once it settled here it worked fine. Not sure whether it is wiring, ignition, or starter.

Question to IH gods: what is most likely the issue? What is my first step in troubleshooting?

 

[Michael Mayben]

On a Scout 80 with factory wiring that was sub-standard, and has a definite case of po virus, there is no telling what ya got going on.

The earliest s80 ('61 and some '62) had no bulkhead connectors, the harnesses from the engine bay simply threads through the bulkhead through a grommet.

Based upon your description regarding the radio in-op, I'd say the ignition switch needs to be replaced, the contacts internally are simply worn beyond use after nearly 50 years! That could definitely be the cause of the "no crank" issue also, but check the terminal connections on the starter solenoid for cleanliness and integrity. Same for the battery cables, remove and clean to bright metal both the battery posts and the clamps.

As you know, there are no fuses or circuit protection used on those vehicle from the factory! The only protection that was used is a self-reset circuit breaker mounted directly to the headlight switch. If equipped with the optional heater, then the heater switch does incorporate a single in-line fuse in it's package. That's it, no other fuses, fusible links, breakers, etc.

IH did use some color-coded wiring, your rig has many "black" wires, and any wiring pigtail that was part of an accessory items (such as the turn signals) were color-coded by their apparatus manufacturer. But...IH used standard truck industry wiring processes, that means numbered wire runs and circuits, not color-code! The numbers printed on each end of the oem wire runs correspond with the circuit number callouts in the applicable wiring schematics found in the service manuals, some of those schematics are being posted here as I have time:

http://www.forums.IHPartsAmerica.com/electrical-tech/5408-ihc-electrical-schematic-library.html

The most common thing I deal with regarding any IH vehicle that has intermittent headlamp issues is the dimmer switch! It's been sitting on the rotten floor, full of water/mud/corrosion forever! That is not anything "special" and a aftermarket replacement is available at any auto parts, same for the connector pigtail repair item.

 

[Drew Merrick]

if this sounds redundant it's because Mike beat me to the post and I was writing it up as he was writing his.. Sorry for that.

I offer this not as pure fact, but just what I would do first. Note... I am not a mechanic, I just play one on tv.

What I would do first is check battery terminals and clean them, then I would check the bat + and - cable for corrosion. Have the alternator tested and battery tested. Check the relay to the lights and wiring to the lights. You can also check the light switch and dimmer switch.

Look at your bulk head wire loom connectors if you have them. These have a high probability of corrosion and should be checked.

By your description your ignition switch sounds to be a bit faulty.

Look at your amp gauge (if you have one), does it read anything? What does it do throughout the process? It is another link in the start system.

It wouldn't hurt to pull the starter and have it tested, but in my opinion it's probably not the first place you should look. It stalled before you had it warmed up so there most likely isn't a hot start issue, but it is another component of the system to inspect. Though, the stalling could also be due to a bad electrical system resulting in a reduced or no charge at the spark plug under load.

When you say po rewire that changes everything. In your case I would also try to get a schematic or circuit list on how everything is wired, checking for proper crimps (or solder if done that way) and looking for any split, broken, brittle wire sheaths and any corrosion on wires and terminals. This would be an electrical audit and would give you a basis to trouble shoot and maintain your system.

Again, this is the course I would take when presented with a nutshell description of your problem. I am not a professional.