No dash or a/c power, weak wipers

1998 2.4, 355k, trying to keep it running.

The a/c on dash has gone out, doesn't appear to be getting power. And the dash display has no power or light. Speedometer not working. Suspect fuel gauge not working. Windshield wipers moving slow.

So I suspect some single problem is causing all of this. If anyone has a wiring diagram or suggestions, thank you.

 

A low system voltage could cause all of those issues. Does the truck start and run?

 

Yes, starts and runs though seems to be missing, rough.

 

I'll check the voltage tonight, good idea.

 

If you have a multimeter, check the voltage at the battery while it is running. And also check it after it has been setting for an hour or two after turning off the engine (resting voltage).

 

Might be ground issue. Bad grounding can cause all sorts of problems.

 

i would firstly guess as others above....voltage/alternator issues

 

Voltage at battery is 12.25 when not running. 11.75 when running. 11.50 when running with lights turned on.

I cleaned the ground from battery to body. Are there other grounds i can check? Inside the cab? I notice that the side-to-side support beam behind the dash is rusted.

 

I had similar symptoms. Bad alternator...

 

Voltage at the battery when running should be 14 volts. Minimum 13 volts.

Poor grounds may be a factor overall but the alternator output is a red flag. 11.75 while running is very low. Either the alt is not producing enough (most likely) or the battery is not accepting the input from the alt.

My first step would be to disconnect the cables from the battery and clean them up and then reconnect to eliminate the possibility it is a battery issue.

 

just bc I just went through this ground thing last week
2rz has 3
One on firewall
One below diagnostic port(front on intake plenum)
One on L inner fender(apron) near battery

my issue was the one by battery

btw
mine shows 13.8v-14.2v when running with AC on

 

Took the alternator to the auto parts store, they said it was good, 14+V, tested it twice.
I notice the battery says 12/21. Seems a little early to be going bad, it was an expensive one. I have it hooked up to a charger now.

 

Where the power wire off the alternator connects inside the BJB, battery junction box, there is a large bolt on fuse, check that too.

 

Check the fuses located inside the cab.

 

Buy a new battery, maybe.

 

I'd want to see if we have any voltage drop from the alternator charge terminal to the battery + terminal.

 

It's pretty obvious there is. If the alt is in fact producing 14+ but at the battery it is 11.75 when the engine is running.

 

May be obvious to you and me. Not OP.
No one had mentioned it yet.

Maybe OP can check and update us.