Jump to content
AHS

520H (late 80-early 90s)

Recommended Posts

cleat

I just went out and checked using my 520HC

 

This is between the grey wire on the tachometer and ground.

 

I get 16 Volts AC at idle and around 34 Volts AC at full throttle.

 

  • Like 2

Share this post


Link to post
Share on other sites
 
Handy Don
1 hour ago, cleat said:

I just went out and checked using my 520HC

 

This is between the grey wire on the tachometer and ground.

 

I get 16 Volts AC at idle and around 34 Volts AC at full throttle.

 

Yep, the tach is definitely getting input so you’re assessment that it’s toasted is likely correct!

When looking for a replacement, remember that this is NOT using the spark frequency but rather the stator AC output that is also charging the battery.

I wrote up a post you might find interesting on this...

 

  • Like 1

Share this post


Link to post
Share on other sites
 
cleat

I am not the one with the bad tach, just verifying what a good signal looks like for the OP.

 

  • Like 2
  • Thanks 1

Share this post


Link to post
Share on other sites
 
AHS
2 hours ago, cleat said:

I am not the one with the bad tach, just verifying what a good signal looks like for the OP.

 

Wow! Scratching my head! I guess ill need to do some more measuring with a volt meter!

  • Like 1

Share this post


Link to post
Share on other sites
 
AHS

Well, my fuse instantly blows once i power up the tach. Ive checked continuity between positive and ground. Ground and the steel bar that wraps around it.. continuity. I dunno.

  • Like 1

Share this post


Link to post
Share on other sites
 
cleat
Posted (edited)

The mounting bracket on the back of the tach passes over the positive and negative terminals but has little plastic insulators where the Threaded terminals pass through. 

 

Maybe the plastic insulator on the positive terminal is broken or missing. 

Screenshot_20240311_201302_eBay.jpg.833ca202d51c3d7586051a512b41c62a.jpg

You can just make them out in this picture.

Edited by cleat
  • Like 1

Share this post


Link to post
Share on other sites
 
AHS
10 hours ago, cleat said:

The mounting bracket on the back of the tach passes over the positive and negative terminals but has little plastic insulators where the Threaded terminals pass through. 

 

Maybe the plastic insulator on the positive terminal is broken or missing. 

Screenshot_20240311_201302_eBay.jpg.833ca202d51c3d7586051a512b41c62a.jpg

You can just make them out in this picture.

So, the ground on the left. The positive is on the right and the signals the lower right? I checked that plastic, and its there. There is continuity for the ground to the mounting strap. There is no continuity between the positive and the mounting strap. Tach junk? Expensive junk!!:)

  • Like 1

Share this post


Link to post
Share on other sites
 
cleat
Posted (edited)

Here is a crude hand drawn picture showing the wiring connections to all the gauges.

 

I= Ignition switched power

G= Ground

S= Signal

 

This is for the metal body SW gauges, the plastic Toro gauges may be different 

 

Wheel Horse gauge wiring rear view.pdf

Edited by cleat
  • Haha 2

Share this post


Link to post
Share on other sites
 
AHS

@cleat That’s the way i have it. Lemme dig into it some more! 

  • Like 1

Share this post


Link to post
Share on other sites
 

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×
×
  • Create New...