Mudski GU Build Thread

[mudnut]

Do not run the engine with the alternator disconnected. I destroyed one once, doing just that. With the multimeter connected in series with the negative to earth (do it on the 10 amp setting), there should be a quick spike in parasitic draw, for the clock and sound system, etc, then should drop to bugger all. If it is above the small milliamp range, then try pulling fuses and relays, before disconnecting the alternator.

[mudski]

Do not run the engine with the alternator disconnected. I destroyed one once, doing just that. With the multimeter connected in series with the negative to earth (do it on the 10 amp setting), there should be a quick spike in parasitic draw, for the clock and sound system, etc, then should drop to bugger all. If it is above the small milliamp range, then try pulling fuses and relays, before disconnecting the alternator.

Hmm, that just went over my head like a low flying duck. I'll YouTube it!

[Rossco]

Yeah I had a bad alternator that had parasitic draw was a PITA. . . When you say don't run motor with alternator discontented Muddy do you mean unplugged but still with belts attached or other way round, and why does this bugger them?? . . .

Sent from my SM-G781B using Tapatalk

[mudnut]

Yeah I had a bad alternator that had parasitic draw was a PITA. . . When you say don't run motor with alternator discontented Muddy do you mean unplugged but still with belts attached or other way round, and why does this bugger them?? . . .

Sent from my SM-G781B using Tapatalk

Unplugged but belt on. A very long time ago (decades) I think had the main output disconnected and started the engine. It blew the regulator by the time I got out of the cab and realised my mistake (maybe 30 seconds).

[mudski]

@mudnut ;
I think I’ve got it set up right.


And after a few minutes it dropped


I noticed even opening the door on the car, even without the interior light on the reading goes up from .08 to .10
From what I’ve read that is normal.


Sent from my iPhone using Tapatalk

[mudski]

Removed every fuse. The only fuse that mad the dmm move was the air bag fuse. From .10 to .09.
Opening the door read more.


Sent from my iPhone using Tapatalk

[Bidja]

Not a collapsed cell in battery?
Maybe put it on chg over night and then have battery joint do a load test.

[mudnut]

@mudnut ;
I think I’ve got it set up right.


And after a few minutes it dropped


I noticed even opening the door on the car, even without the interior light on the reading goes up from .08 to .10
From what I’ve read that is normal.


Sent from my iPhone using Tapatalk

The reading is a little on the high side, but a fully charged battery should handle it overnight.

[PeeBee]

Not a collapsed cell in battery?
Maybe put it on chg over night and then have battery joint do a load test.

I would expect a collapsed cell would be in the order of 2.2V drop not 11V.

[mudski]

So I have found the culprit, but not sure how to fix it.
This first pic looks of the dmm you can see the circuit breaker is off.



This breaker is fed from the main battery and goes to a fuse block, this fuse block feeds power to each relay, Oem and aftermarket in the original relay housing.


Probably 10 years ago I modified the relay box to house all the added relays that were strewn all through the engine bay. It has worked really well.

This is what happens when i activate the breaker.


I tracked it down to fuse number 4, which feeds the relay for the spot lights.


I remove the fuse, the reading drops. I put the fuse back in and remove the relay. Nothing. It stays the same!
Why?
This is about as far as my lecky knowledge goes with fault finding.

Any ideas for what to do next?

I removed every relay also with no change.


Sent from my iPhone using Tapatalk