1993 Dodge Dakota LE, 5.2L, auto trans, RWD, 180,500 miles, original owner

EDIT NOTE: If you want to cut to the chase, pull up Post# 130 in this thread to get to the solution. Everything else is trial and error but could be useful to you if you want to read it all.

One thing about a 28 year old vehicle is they always remind you they are 28 years old. The latest is my volt gauge on the dash. All of a sudden I notice it has the heebie jeebies. It vacillates a couple volts back n forth. Only when idling in park or drive. Once you put a load on the engine she steadies herself. Put the multimeter on the battery at idle while the gauge shakes and it holds at 14.1 volts +/- a few hundredths.

History: My PCM took a crap about a year and a half ago. Long story short I put a rebuild on the truck. Works perfectly fine but the voltage regulator in the rebuilt PCM was crap. Rather than get another rebuild, I kept it and, on the advice of Hey You, I installed an external voltage regulator (adjustable). Installation was fine except I was using wimpy wiring and the dash gauge had a severe case of the shakes. I replaced the wimpy wire with fatter wire (think I went from 14 gauge to 12 gauge) and the problem totally cleared up and I've been thrilled ever since. So now the dash gauge shakes again (no where near as bad as when I had the wimpy wiring from the external regulator installation) but it shakes nonetheless. I could hear Ralph telling me to check all the connections. So I did and they were all cinched down. Made no difference in this case.

So my questions are: Should I ignore the cheesy dash gauge? Is this a possible sign my 1-1/2 year old adjustable external voltage regulator has a case of Parkinsons or similar malady?

Your thoughts and opinions, as always, are appreciated.

 

The digital volt meter may not see the pulses that make the analog voltmeter dance.

But yes; I'd check the connections. Again.

I'd remove and reconnect the ground connection.

But - that also means "check the connections for the METER".

Including the ground inside the dash.

RwP

 

Any idea where to look for the ground inside the dash without ripping half of it out?

 

I think I have an old Simpson analog meter somewhere. My dads from way back in the day. I have no reason to think it doesn’t work. Maybe I’ll dig it up.

 

That Factory Service Manual *grins*

Since you have the 1995, it says "The grounding point for circuit Z1 is instrument panel lower right reinforcement support." And that circuit Z1 is the ground for the instrument cluster (lists each one separate in the 8W section).

I've attached the page from the 1993 FSM that shows the panel ground.

RwP

 

Awesome! When it comes to electrical I cringe. But even that illustration makes it easy for electridiots like me to understand.

Thanks for chasing that down for me. Now I’ll have to study that electric section of the FSM while I’m riding a wave of confidence.

I’ll get on those connections tomorrow. You don’t have to twist my arm much on checking connections. I’ve seen bad ones rear their ugly heads enough to know it is always a good place to start. And usually not too hard to do.

I’ll post my results tomorrow. Thanks again!

Will it be a black wire?

 

Dunno offhand; but there's nothing BUT grounds there, so no matter what color it is ...

RwP

 

Ralph, is this the FSM I want? Just want to double check. And you said I should be able to copy it to my laptop and backup device?

https://www.ebay.com/itm/15279038504...3ABFBM4JXj6pxf

 

I bought it. I remembered you said it was Bishkos. Funny, it was listed at $30 when I linked you. I went back a little later and it was listed at $44. I’m like, what the heck? Went back a little later and it was listed at $29 so I pulled the trigger. Puzzling.

 

That'll do it.

Bishko's web site had it at bout $40 last I checked on sale.

And yes, it's an unprotected PDF.

RwP