AC issues

[CampYerr]

Hey Mates, I’ve had a couple of ac issues since purchasing my van last April.



First, I have been having issues with my AC Fuse Link. I replaced my AC link 4 times since last April and trying to figure out why it’s happening so often. Last year DelicaUSA worked on fixing this leak and said it was fixed and also replaced the ac link with an Inline fuse. After a hefty bill, I didn't see anything changed other than the inline fuse and a recharged. Same condenser and compressor, I also never received an itemized bill so there's that. After that, I replaced that with a new ac fuse link from sk66 and did a full cleaning of my battery bay, cleaned each connector, and applied dielectric grease. I do know that the fuse link gets really hot hence eventually burning out. Since this had happened again on my way down to Texas I’m curious to hear what you guys think is causing this. Really don’t want to drive back to NYC without AC and summer is approaching so just want to get everyone’s thoughts before I replace the ac fuse link again.



So I’ve noticed a newish 12 gauge wire coming from the compressor. One thing that has been common every time this has happened is that the ac fuse link has always separated from the wiring harness side. Also, both have burned/melted at the spade crimp. I will need to replace the female connector at the wiring harness side as I saw there was a good burn inside the female connector, and the connector as a whole looked burnt out as it felt like it was almost melting into the male connector.



Lastly, my ac has constantly had a small slow leak. DelicaUSA said there was no leak, yet I still have to recharge the AC pretty frequently. I have looked everywhere and can’t find anything with the leak detector. My mechanic also didn’t see a sign of a leak after having the van in his shop for a few days. He also said there was no pressure loss. Yet, my AC eventually goes out.



Please let me know your thoughts and ideas about both issues. Thank you.

 

[sk66]

Check the fuses behind the glove box to make sure they are the right ratings (one 10A for compressor clutch, two 15A for condenser fans). The fusible link provides the power to those consumers, through the fuses... I would think the fuses should pop before the link burns out. The diagram has the clutch wire as 0.85 sq mm, which is between 18 and 19 AWG; far smaller than 12AWG so that's a bit of a concern.

The condenser fan is the big draw item on that circuit... it has the 15A fuse protecting it, and a starting capacitor in parallel with its' power relay. The capacitor means the motor has a larger starting surge load... but that is only momentary i.e. IDT it is the surge load burning out the link. A bad capacitor could create a ground short (would be unusual), but I would think that would be a more rapid burnout situation and that should take out the 15A glass fuse (protecting the link). I think the most likely situation is a jammed condenser fan motor, of the two the main is the bigger load/draw, but I would think the one in front of the passenger side wheel is most likely to be messed up.

Do you have a clamp type amp meter to see what kind of current is being pulled through that link? It really shouldn't be that much. You could just use a short piece of 18 or 20 AWG to temporarily jumper it and get readings. What I would do is disconnect the condenser fans and see if that drops the load (amps)... if it doesn't then the issue is the clutch; if it does then reconnect the fans one at a time. Not having the fans working might cause the AC to cycle more (?), but IDT there would be any risk of damage to the system.

 

[CampYerr]

So I followed that 12 gauge cable that was going down to the front of the engine and saw that it was spliced. So I’m definitely going to un-splice it and put the proper size. I’m gonna try to get access to a clamp meter and check all that stuff out. Thanks @sk66. I’ll also PM you for the links and bits

 

[CampYerr]

Easy fix on this side. But yea this wire is definitely not 18awg I think it’s like between 12-14. What are your thoughts @sk66

 

[sk66]

The W wire is 5 mm sq (11 AWG), and after the 0.5 mm sq fusible link (20 AWG), the B wire is 3 mm sq (14.5 AWG). But then it steps down to 2 mm sq (15 AWG), 1.25 mm sq (16.5 AWG), and 0.85 mm sq (17.5 AWG) after the individual circuit fuses (behind glove box)... it should not be 12 AWG direct to the compressor clutch.



This is the most involved AC configuration with the heaviest gauge wires... but all of the AC diagrams/circuits have the same compressor clutch wiring (3 mm sq after the link and 0.85mm after a 10A fuse then through a power relay).

Of course almost none of the metric wire gauges translate into readily available american standard wire gauges; generally it is best to error heavy on wire gauge and low of fuse/fusible link ratings.

 

[CampYerr]

Oh yea, all glass fuses behind glove box are good, condenser fan is working when connected and stops when ac is off, and an audible click when ac is turned on, and did a clamp test.

 

[sk66]

Connected how? Are you using some kind of jumper wire attached to the end of the link?

At first I was thinking there's no way you should be having an issue w/ less than 1A burning out a 27A link... but unfortunately those numbers are useless. That is an AC clamp meter and the electrical system in your van is DC. DC clamp meters are much less common/harder to find; this is the one I have.

 

[CampYerr]

Oh lol. Sorry grabbed the wrong one. Also just little knowledge with electrical stuff. I have a strip of 14awg wire connected to the fuse line.

 

[sk66]

21A seems like a lot to me... the fusible link is only rated at 27A. It makes sense that it would be hot at 21A if it's supposed to burn out at/above 27A; but IDK what it "normally" carries.

We know there are three consumers on that circuit. I would connect them one at a time and see what difference each one makes... see if one item is pulling a lot. But at the same time they're not blowing the fuses behind the glove box so it shouldn't be too much... are those fuses the right ratings?

I've been running the same fusible link for many years w/o issue, and many others are using them as well w/o issue (AFAIK). But I do have an OEM green link on hand... when I get some time I'll do some digging/testing to see if I can find anything significantly different (test the links resistance/capacitance/inductance, see what load mine is carrying, etc).

 

[CampYerr]

I can do some unplugging later and see what happens. I went back and verified all fuses are not blown and matched with what was labeled. Oh yea, I did notice that the 2 middle 20 and 5 amp fuses were newer AGC fuses.

 

[sk66]

AGC fuses are correct...
I tried to find a wiring diagram showing 20A fuses with no luck; but that looks stock/correct to me.

FWIW, I did measure the OEM green link compared to a new gray one; and they are exactly the same in resistance (0.7ohm) and capacitance (0). I couldn't measure the inductances because my bench meter is throwing a fault; but that measure should be irrelevant anyway. If I get a chance today I will measure the amp load and see what fuses are behind my glovebox.

 

[sk66]

Pulled my glove box out; I only have the three AC related glass tubes there, and they are 15A/15A/10A like the diagram shows. My van's a '91 Exceed...

I tested the AC load on that fusible link with everything running at max, front and back. I saw as high as 22.6A when the condenser fans were running (a little surprised it was that high).

I also felt the link and it did seem to get a little warmer, so I pinched the meter's temp probe against it to get a measurement... the temp varied between 98˚ (body temp) up to 102˚ under max load. With the temp probe inside the connector next to the spade/crimp the temp varied between ~ 85-95˚. My condenser fans never ran that long so IDK if it would have gotten any hotter, but those kinds of temps are not a problem. I do know that I've used the AC non-stop for 6 hour drives w/o issue; so apparently 22.6A isn't a problem on that link.

 

[CampYerr]

My van's a '91 Exceede

I have P35W HSRGT2 Super Exceed (Crystal-LITE ROOF). I wonder what the other 3 wires are? I assume the AC ones are the 5/10/20 wires. Gonna start unplugging to see if the AC is affected. After I will spice in that 14awg cable, connect the new fuse link, then go drive around all day and see what readings I have. I also think I have a temp gun to see if I can get a reading on the wire.

 

[sk66]

I assume the AC ones are the 5/10/20 wires.

No, it's the other three... the wiring colors agree with the diagram; 10A White/red stripe- compressor clutch, 20A Red/white stripe- side condenser fan, 20A White- main condenser fan.
The connectors are made from nylon and have a melting temp around 500˚f... I would run 18 or 16 AWG; but heavier isn't going to hurt anything.

 

[CampYerr]

So I ended up running test with both 18 and 16 awful wire. I disconnected each wire and took a reading and also verified that part was not running.


16 AWG test


18AWG test

 

[sk66]

So I ended up running test with both 18 and 16 awful wire. I disconnected each wire and took a reading and also verified that part was not running.

Everything looks pretty much as I would expect... main fan pulls the most, clutch pulls the least, 16 vs 18 AWG makes no appreciable difference; and there's no way that link would burn up/fail at 110˚f.

It's confusing to me... it's possible you've fixed the issue by running a new wire; but no problem was actually found (?). It's also possible that the issue is actually an intermittent short that isn't occurring at the moment... something in the wiring bundle after the fusible link and before the glass fuses.
Unfortunately, I would be more inclined to suspect the latter...

---

I do have a little concern that the glass fuses are at 20A and maybe you actually need a slightly higher rated fusible link as well (different part# ?) ... I've never seen/heard of that, but I'm sure there's plenty I don't know about these vans.

 

[CampYerr]

I have some extra fuses. What are your thoughts of me placing the fuses as it's outlined in the wiring diagram and running it like that on my drive back to NYC from Texas and seeing what happens? It’s about a three-day trip, so I’ll definitely get a lot of use out of the AC.

 

[sk66]

Well, it wouldn't hurt anything... and it might give you an idea if it's one of the consumers occasionally overloading the circuit. But I kind of doubt it is.

What about keeping the temp probe inserted in one of the spade housings next to the link wire? If there's enough probe wire length that you could monitor temp and see if seems like it's overloading at any point. That would be the time to identify the issue; when it's occurring... of course, on the road is not very convenient.

 

[CampYerr]

Well, it wouldn't hurt anything... and it might give you an idea if it's one of the consumers occasionally overloading the circuit. But I kind of doubt it is.

What about keeping the temp probe inserted in one of the spade housings next to the link wire? If there's enough probe wire length that you could monitor temp and see if seems like it's overloading at any point. That would be the time to identify the issue; when it's occurring... of course, on the road is not very convenient.

Ok so swap to lower rated glass fuses and on day 2 AC fuse link blew. Glass fuses are all good.

Day 1 didn’t get much use. Rain and cold most of the day. Maybe about 6-9 hours of AC. Forgot to check wire temps too SMH.

 

[Growlerbearnz]

Apologies if you've done this (I skim read to here) but I would follow/inspect/clean the AC wiring loom from the battery all the way to the AC unit behind the dash. From memory it runs along the inside of the engine bay, past the radiator, and then comes up through the floor with the refrigerant pipes.
I'd be looking for signs of physical damage, something that's rubbed through and is shorting to the chassis.