24 volt system charging batteries at different rate (1 Viewer)

[Greg_B]

They are not showing what they should show that is I'm missing 24v.
Dimmer relay pooched? What does this relay do?

The relay switches connections inside the body of the relay and directs 12V and 24V to the correct wires in the low and high beam settings.

You're at the point that you either build your own system for 24V headlights, or you you really dig into your harness and try to make the stock setup work. Or at least find out where the issue is so you don't have a live wire deadheaded in the harness somewhere.

If you want to attempt to make the stock system work I would find the dimmer (headlamp) relay (try on the drivers side, around the steering column or footwell area, or in the left kickplate panel. Those would be my two guess's. Look for the number 85926 on it. Disconnect the relay. Check all the fuseable links on the 24V side at the battery for continuity. There should be a hot 24V and hot 12V lead coming into the relay. Check continuity of each wire from the connections to the headlight pin (will be the same color from the connection to the pins). If continuity is good on each wire, chances are it's in the relay.

If you go this path, please post your results (where the relay is, what color wires have the 24V and 12V inputs) etc so it is recorded for the next person who has to clean up their system.

I had a PO nightmare on my BJ42. Had to pull the headlight harness back to the firewall (thankfully not into the dash) to find where the PO cut and sliced. Repaired that, and the dimmer relay was ok, so it was relatively easy. Hopefully others will have some ideas that might lead right to where the problem is.

gb

 

[jetswim]

The relay switches connections inside the body of the relay and directs 12V and 24V to the correct wires in the low and high beam settings.

You're at the point that you either build your own system for 24V headlights, or you you really dig into your harness and try to make the stock setup work. Or at least find out where the issue is so you don't have a live wire deadheaded in the harness somewhere.

If you want to attempt to make the stock system work I would find the dimmer (headlamp) relay (try on the drivers side, around the steering column or footwell area, or in the left kickplate panel. Those would be my two guess's. Look for the number 85926 on it. Disconnect the relay. Check all the fuseable links on the 24V side at the battery for continuity. There should be a hot 24V and hot 12V lead coming into the relay. Check continuity of each wire from the connections to the headlight pin (will be the same color from the connection to the pins). If continuity is good on each wire, chances are it's in the relay.

If you go this path, please post your results (where the relay is, what color wires have the 24V and 12V inputs) etc so it is recorded for the next person who has to clean up their system.

I had a PO nightmare on my BJ42. Had to pull the headlight harness back to the firewall (thankfully not into the dash) to find where the PO cut and sliced. Repaired that, and the dimmer relay was ok, so it was relatively easy. Hopefully others will have some ideas that might lead right to where the problem is.

gb

Well, I'm going to first try to make stock system work as, for the most part, it does.
I have the body & chassis manual and have located the switch but of course I have my family up for the weekend so might not get to it right away.
Will definitely post results. Thanks to all who got me this far and I hope I get this baby charging like she should.

 

[kim]

The dimmer relay is in the drivers side footwell.

 

[jetswim]

The dimmer relay is in the drivers side footwell.

Dimmer relay. Numbers are not visible but it does say dimmer relay on it.

 

[jetswim]

Dimmer relay. Numbers are not visible but it does say dimmer relay on it.

With the engine running and headlights turned to on position i get +12v on the upper right corner and 2 down from it on the right side is +24v. The rest were all zeros.
Now how do I check continuity in the wires?

 

[Greg_B]

Did you get this sorted? Was up in Whitehorse and did not take any net time.

gb

 

[jetswim]

Did you get this sorted? Was up in Whitehorse and did not take any net time.

gb

Spending this afternoon on it. Will post results later. thanks bro

 

[jetswim]

+UPDATE-
There was a burnt red/green wire that went from right side headlight. It had long since melted and was replaced by a pink wire. The wire went to a patch with one end going to a R/G wire to the switch and the other to the dimmer relay. Which dimmer relay I'm not sure. The one pictured above with 8 connectors is called 'DIMMER RELAY' on the unit but the rest was corroded off so I can't read it. Maybe one of you stock CDN 1987 HJ60 owners can post a picture. It is on the driver side kick panel, left fender wall right near the floor.
The other dimmer relay was the one mentioned above with the number 85926. It's a square one located on the relay chain under the drivers side dash.
Either way after the soldering of some iffy connections, checking power to and from terminals, accidentally blowing a headlight, subsequently installing 2 used headlights with soldered connections, and charging the low side battery 2A for half a day as well as all the stuff in the previous posts, the batteries now charge equally at 13.7+ for about a week now. Both batteries test 12.7+ after overnight rest.
I think the R/G wire which had melted and was replaced was possibly put on the wrong terminal of the headlight either after replacement or when headlights were replaced by PO. Thanks to this post https://forum.ih8mud.com/diesel-tech-24-volts-systems/494633-what-f-headlight-wiring-help-hj60.html and kims info of the voltage of these wires and greg_B for his insights. The R/G wire provided 24v to the 12v headlight but there is also 12v coming from the R/B wire. With the connections messed up it was enough to light the headlight but somehow the charging rate was interrupted so that the battery on the screwed-up-connected-headlight side was cooking while the other barely charged at all and in fact with the headlights on it increased to 15+ charge on the high side and 12.4+ charge on low side. YIKES!
My FSM is from 1984 and doesn't 100% match up with the wiring in the 87 but it still helped. It didn't have the second 8 pin dimmer relay listed though. I'm wondering how this relay plays into this system.
Cheers...

 

[jetswim]

Well the problem seems to have returned. When headlights are on the high side battery gets cooked while the low side battery slowly gets undercharged. Time to open up the dash to get at the harness. Not good with a heat wave coming up. The r/g wire that was melted and replaced might still be attached somewhere or maybe a relay is causing problems. Will get to it soon I hope.

 

[kim]

Well the problem seems to have returned. When headlights are on the high side battery gets cooked while the low side battery slowly gets undercharged. Time to open up the dash to get at the harness. Not good with a heat wave coming up. The r/g wire that was melted and replaced might still be attached somewhere or maybe a relay is causing problems. Will get to it soon I hope.

Returned implies that the problem 'went away' for a while. Is this so?

 

[jetswim]

Returned implies that the problem 'went away' for a while. Is this so?

Yes. We got to a point where I was getting the proper voltage out of the head light wires and things seemed right. Now I'm not getting 24v from the high side headlight anymore so either something moved or ??
The headlights still work but batteries are affected somehow when lights are on. The replacement wire goes from the headlight to the steering column where it is patched to a r/g that goes to the switch. It also attaches to a r/g wire that disappears back into the harness so maybe it's touching something.

 

[Greg_B]

Sucks. Hope you get it sorted.

gb

 

[jetswim]

Sucks. Hope you get it sorted.

gb

Well, after removing the dash pad to gain access to the harness the burnt wire was traced to the fuse box where it was still connected but going nowhere and possibly causing problems. So essentially you could pull the headlight fuse and the RS headlight would stay on. The replacement wire, instead of going all the way to the fuse panel, went to the wire from the headlight switch to the relay(s) thereby bypassing the fuse. Crazy eh? Well it was a quick fix for the PO as the headlights did work but not a complete and proper one. Also found a spot where another wire was affected by the burning so it could have been causing problems as well.
After hooking the replacement wire directly to the fuse panel and severing it from the "patch" all seems good. Batteries are charging equally at almost the same voltage with the headlights on and I'm getting proper voltage at each headlight. Will monitor it the next little while to make sure.
FYI there are 2 dimmer relays in my HJ60. One by the driver side kick panel and one in the relay chain. The one by the kick panel says 12V on it so it makes me think it has something to do with supplying 12V to the headlights. It has eight connectors and heavier gauge wire going to it. Will post a photo of the part number as i got a replacement one with legible script.(Thanks Willyota!)

 

[jetswim]

8 pin dimmer relay, 1987 hj60, Driver side kick panel.

 

[jetswim]

Sketchy wiring! Notice the bare wire coming from the fuse panel and going nowhere!