71 W200 will not crank - "brake" light on key turn

[idaho68d200]

Howdy,

Recently picked up my 71 W200 w/383 & NP435. It's been working quite nicely but I parked it one evening at home and went to start it later when I got the "brake" light to come on when I turn the key. I've had the 68 D200 with the 383 and 727 and have observed idenctical behavior on that truck if the transmission is not in park or neutral (or is close to either), but on this truck, the trans is in neutral and for the heck of it I put the t-case in neutral and had the clutch pedal depressed all the way and had my foot on the brake.

The ONLY thing I can even think of is the fact that I changed the front park/turn lightbulbs from clear to amber to go with the clear lenses on the truck, but it just doesn't make sense... My only guesses would be ignition switch or more likely in my mind, starter relay, or ballast resistor... Never had any of these go bad, so prior experience would be helpful.

Thanks,

[shearingmatt]

The 71 is is a different beast than the 66 that I have under the hood. But, do you get any clicking when you turn the key. With the truck in Neutral have you tried jumping electricity to the solinoid? If it turns over that way, its probably an issue with the wiring or the solinoid. Y'know that there is enough electricity in the battery to kick it over. Brake lights don't use nearly as much electricity as a starter so its possible you are getting a brake light but not having enough juice to power the starter.

Matta

[shearingmatt]

For that matter, if you are going to do this. make sure that you have the E brake on and the wheels chocked. It wouldn't be all that hard to make a mistake and have the truck drive off with you hanging out of the hood. :-)

Matt

[idaho68d200]

There are absolutely NO noises when I turn the key and by "brake" light I mean the one on the dash, not the brake lights in the rear. Everything is in neutral, battery is fully charged and has a good connection.

I'm thinking ballast resistor or starter relay... thoughts appreciated

Thanks

[digdoug]

I would do as Matt said,and try jumping across the posts on the starter relay.That is a good place to start.

Doug

[nfury8]

The dash Brake light coming on is typical, and a good indication that the truck is getting juice as it should.

I would do as the others mentioned and short across the starter relay. When you do this it puts current directly from the battery to the starter, a quick and easy way to eliminate a common problem. The starter has the solenoid built in. By jumping the relay you will be able to hear the starter better with your head under the hood. Listen close for any minute sounds. Sometimes a bad solenoid will make a noticable sound, sometimes it can be barely audible. Do the lights dim at all when you turn the key? This is an indication that the starter is atleast trying to pull some juice.

When a ballast resistor goes out the truck should start as normal, but die as soon as the key is released.

I don't know why, but all my older Mopars love to eat starters. Between the 4 of them, I have to diagnose this about once a year.

[cowboy]

if you loose the ground from body to engine , you'll get nothing, if the ballest resister goes south on you you have nothing , you can try the ing just pull one that you know is good , & try that

[cudajimmy]

I'm with Cowboy....Ground or ballast resistor.

[Russ]

A bad ballast resister will not cause this problem. If the ballast is bad the truck will crank as normal but die when the key returns to the run position like someone already mentioned. Also the brake light coming on when starting is correct. This is the lamp test, as you probably will never see that light otherwise.

[cowboy]

Russ is right , about the ballest resister, I forget it would crank then fall out when you let the key go to the run spot

[Ambulance62]

in cold weather the starter relay can get sticky ,,..seen this happen before. Try tapping on it with a screwdriver- might do the trick. then switch to the newer electronic type to eliminate the old one with contacts....

[Thomas]

The dash Brake light coming on is typical, and a good indication that the truck is getting juice as it should.

I would do as the others mentioned and short across the starter relay. When you do this it puts current directly from the battery to the starter, a quick and easy way to eliminate a common problem. The starter has the solenoid built in. By jumping the relay you will be able to hear the starter better with your head under the hood. Listen close for any minute sounds. Sometimes a bad solenoid will make a noticable sound, sometimes it can be barely audible. Do the lights dim at all when you turn the key? This is an indication that the starter is atleast trying to pull some juice.

When a ballast resistor goes out the truck should start as normal, but die as soon as the key is released.

I don't know why, but all my older Mopars love to eat starters. Between the 4 of them, I have to diagnose this about once a year.

I go through a lot of starters too....

[idaho68d200]

Thanks for all the suggestions and advice... I made it back into town and right away opened the hood and tapped on the relay. Cranked right over as normal after that.

It's probably something I should just replace since it's cheap, but my buddy with a Ramcharger says he's kept the same old one in his truck but has to tap on it once in a while to make it work...

Thanks...

[JJ]

Pull the wires off the relay and clean the terminals. That has fixed more then one