Bypass Neutral Park Switch

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JeepManDan

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Location
Colorado
Ram Year
1989
Engine
5.9 V8
1989 Dodge Ram w150 5.9 often doesn't start appears to be neutral/park switch. I replaced the switch but no change. Local mechanic says there's a arm inside the transmission which may be bent or broken. This is just a plow truck, anyone know how to bypass the wires on that switch so it will start?

I realize the value of the switch and the risk it could start in gear. It's not a daily driver and not driven often.
 

B250

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Location
Rhode Island
Ram Year
1991
Engine
5.2L V8 MFI
I have a B250 and looking at the wiring diagrams the 1989 years are basically the same as the 1991 years. I don't have 1989 wiring diagram scanned, but I have a 1991 and I've attached it to this post.

The BR/YL wire from the tranny switch is connected to the starter relay (PIN 2) and simply grounds when in neutral to engage the starter motor. On the 1991 models the BR/YL also connects to the ECU but on the 1989 models it connects directly to the ignition switch via the starter relay. Also, have you replaced the starter relay itself? They also wear out after 30+ years! (usually working intermittentently before failing completely)

I've highlighted the neutral safety circuit (BR/YL) in blue on the diagram. The yellow box on the bottom left is the 1991 circuit for the ECU
 

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threewheeler80

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Florida
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1985
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318ci
The middle wire grounds the starter relay circuit. The outer two are for the backup lights.


... I think!?
 
OP
OP
J

JeepManDan

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1989
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Thanks B250 and threewheeler80 this diagram is great. We replaced the switch with one from a parts supplier and so far it seems to be working. Per the shop who obtained it for me the one I got from an auto parts store was bad and the one they got costs more but is better quality. Don't you love installing a brand new part that works no better than the 32 year old one? Thanks all
 
OP
OP
J

JeepManDan

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1989
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Update, the one from Oreillys was bad. Got second new one from a parts supplier to a local auto shop and it works. Hate that
 

threewheeler80

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I doubt the replacement parts I have installed will last 37 years or even half that long.

For some reason I am keeping all the original parts.

Good luck
 

Dodge trucker

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1985
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225
I had that same issue with my 96 Dakota.
Sometimes it would start in park other times I had to put it in neutral. (But it always started one way or another) I put it on the lift and had someone inside moving the shifter while I was underneath watching it move. I replaced the shifter linkage bushings on the column and on the cross shaft. While I had the linkage apart I discovered that the lever that bolts to the trans was loose
I tightened that up and no issues since. For the few bucks I spent on shift linkage bushings I don't feel bad about that anyway since my truck has 237k on it and is 26 years old.
 

Dodge trucker

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225
I did have 1 Dakota that I bypassed that center wire to the neutral switch, on which I had also converted from an auto to a 5 speed. The original automatic took the same neutral switch as the OPs truck.
 
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