Dash gauge spikes to 30V (1 Viewer)

Joined
Oct 10, 2020
Messages
22
Location
corvallis, or
1989 HJ61 285,000 km

I’ve owned this gem for about three months. About a month ago, I noticed the dash voltage meter bounce a little and the lights get a little brighter and the fan speed up...just a little. Every once in a while, when I first start the truck, the volt meter jumps right to about 30v and stays there. The battery light is on, and oddly the turbo lights in the tachometer also come on. I’ll turn off the engine and restart...volt meter reads normal, most of the time. Lately, I’ve had to turn it off and on a couple tomes before it stays normal.

somethings wonky with my electrical charging system. After reading about the voltage regulator and alternator, I think I’m headed down the road of replacing my alternator first. Any advice, or other ideas?

75C690CA-39E7-4C23-8FC0-6D3927C2D8D7.jpeg
 
Joined
Mar 31, 2016
Messages
132
Location
Los Angeles
So reading through the FSM for 2H,12-HT it seems the Voltage regulator is replaceable for both internal and external. Quoting the FSM regarding internal type
Screenshot_20210116-230539.png
 
Joined
Mar 31, 2016
Messages
132
Location
Los Angeles
One last suggestion is measure the actual Voltage with a multimeter at your batteries to rule out a false reading from your gauge.
 
Joined
Mar 31, 2016
Messages
132
Location
Los Angeles
Take it off and open up the housing ,visually inspect it for damage such as burnt coils or blown out capacitors. If everything looks good follow the procedures outlined here. I had charging issues on my BJ42, and was able to find the cause of my problem was my alternator not charging after verifying that my regulator was good.
Screenshot_20210117-003033.png
Screenshot_20210117-003108.png
 
Joined
Nov 11, 2007
Messages
900
Location
Vancouver, BC
Dollars to donuts it your regulator, my BJ60 (12v) has an IC internal regulator which gave out about 10 years ago, the meter would spike as the engine revs increased (I’ve never seen my windshield wipers work so fast!), no voltage regulation from a good alternator. Luckily it was a very easy replacement (a cheap stock item at the local auto electric shop) for me.
 
Joined
Oct 10, 2020
Messages
22
Location
corvallis, or
Take it off and open up the housing ,visually inspect it for damage such as burnt coils or blown out capacitors. If everything looks good follow the procedures outlined here. I had charging issues on my BJ42, and was able to find the cause of my problem was my alternator not charging after verifying that my regulator was good.
View attachment 2555747View attachment 2555748

Followed FSM instructions to diagnose voltage regulator. All of the readings are close, but some were 10% above or below the target.
And a little bit of rust inside!

is the external voltage regulator a part that’s easy to find, without being sent from EU?
 

bcsteel

SILVER Star
Joined
Oct 31, 2008
Messages
602
Location
Terrace, BC
Have you inspected your VR. Worth opening up and looking. Mine did same thing. Replaced one wire and charging/regulating fine now.
 
  • Like
Reactions: D0g
Joined
Nov 11, 2007
Messages
900
Location
Vancouver, BC
I believe the regulator output should be 27.5v +-.3v . As the external regs seem to be NLA from Toyota , it would be worth while to take it to an auto electric shop for proper testing to confirm condition. However, it sounds like it was/is intermittent, which could possibly be a poor connection or a failing wire.
Here’s an option with the same P/N for the 24v 40a regulator;
27700-57051
854C7F90-47C8-415A-B790-3A969CD6B1F6.jpeg
 
  • Like
Reactions: D0g
Joined
Mar 31, 2016
Messages
132
Location
Los Angeles
Followed FSM instructions to diagnose voltage regulator. All of the readings are close, but some were 10% above or below the target.
And a little bit of rust inside!

is the external voltage regulator a part that’s easy to find, without being sent from EU?
I was able to find mine from my local dealership. @roalco posted the part number try calling your local dealership or search for it on their website. A failing alternator usually doesn't charge, so I'm going to say it's most likely your regulator is bad.
 
Joined
Oct 10, 2020
Messages
22
Location
corvallis, or
Another note. My 60 with 12ht has electric issues as well. I inspected main ground off of battery and it was in horrible shape. Would recommend checking these as a start before you throw bags of money. Simple easy baseline to go on. Then throw money away.
I’m suspicious of this very thing.
And I’ve already thrown bags of money away. Searching through parts websites is way worse than cruising Amazon
 

BreckenridgeCruiser

I break things.
SILVER Star
Joined
Aug 14, 2006
Messages
3,816
Location
Oceanside and Encinitas, CA
I had similar issues and it was a bad ground to the starter... I replaced it with a better wire and cleaned up the rest of the grounds and all issues went away... That was after dropping $$$ on a new 24v starter, but now I have a very pretty paper weight ( and spare ) from the ordeal!
 

Users who are viewing this thread

Top Bottom