mystery plug....can you help identify it?

[tshandonay]

Was eyeballing the underside of my newly obtained 99 LC and noticed this plug on the drivers side near the oxygen sensor plug that was not attached to anything.

Also....is that a coolant drain plug on the block?

Thanks folks....nice to be back after parting my 80 a couple years ago.

 

[Greenbean]

Well I can't help with the plug, but you have me planning to crawl under my newly acquired 100 to check that drain opening or seems to be.

I swear I smell coolant burning at times but never in the cab, only after I'm done driving and I'm around the vehicle. PO replaced the radiator, coolant, and all other kinds of things before I purchased it.

I can say I have found a pigtail of wiring near the right front firewall under the hood with three plugs just sitting there unused. Wonder what they are also.

I have some FSMs coming with the EDM so maybe I'll spend some free time reading and hunting.

 

[tshandonay]

Well I can't help with the plug, but you have me planning to crawl under my newly acquired 100 to check that drain opening or seems to be.

I swear I smell coolant burning at times but never in the cab, only after I'm done driving and I'm around the vehicle. PO replaced the radiator, coolant, and all other kinds of things before I purchased it.

I can say I have found a pigtail of wiring near the right front firewall under the hood with three plugs just sitting there unused. Wonder what they are also.

I have some FSMs coming with the EDM so maybe I'll spend some free time reading and hunting.

Let me know if you have the same open plug when you do take a look.

 

[Greenbean]

Let me know if you have the same open plug when you do take a look.

10-4, I'll be under there tomorrow morning.

 

[bjarnep]

You will find many "unused" plugs on the 100 – generally, all connectors are there for all kind of accessories – Headlight washers – headlight height adjustment – extra heaters – speed pilots and so on. Normally it is not something that are “missing”
On the other hand it is not always, if you buy the accessories, it will work – there might also be other wiring missing for the extra things to work. I did buy 2 height adjusters for the headlights and connected them to the appropriate connectors – but cannot make it work, some cables inside the vehicle are missing.

 

[jLB]

I can say I have found a pigtail of wiring near the right front firewall under the hood with three plugs just sitting there unused. Wonder what they are also.

I'm pretty sure that the (under hood passenger firewall) connectors that you are referring to, is where the fetzer valve goes:

What are these connectors?

What are these extra connectors for?

What are these connectors for

Mystery wiring harnesses

What are these connectors for

Is something missing?​

(it's the AHC harness)

 

[2001LC]

All 100 series have that open plug near the engine block coolant drain on DS. I've asked and nobody has come forth. You'll find many open plugs stash around your 100 series, even if you have every option available I'll bet you'll still find some.

While under shields off, it's a good time to check both forward & aft weep holes for signs of leaks.

Aft weep hole at front of bell housing where it bolts to engine. Notice wet lined stain, this is from cleaning top of engine. Soapy water gets into engine valley under intake manifold. There are two drain holes at back of engine valley on either side of starter. Here you look for coolant, oil or ATF weeping.

Forward weep hole (red arrow) just behind harmonic balance with drive belt in it's pulley (yellow arrow). Look for oil or coolant.

Check your steering rack bushing as well. They're almost always soft, allowing rack to move back and forth as you turn steering wheel with both wheels on the ground.

 

[tshandonay]

I'm pretty sure that the (under hood passenger firewall) connectors that you are referring to, is where the fetzer valve goes:

What are these connectors?

What are these extra connectors for?

What are these connectors for

Mystery wiring harnesses

What are these connectors for

Is something missing?​

(it's the AHC harness)

Wow....I honestly did search and didn't come up with much. I have some things to learn apparently.

I have noticed other plugs in the engine bay that are not used and figured they were for heavier optioned models or the LX, but I found this location unusual. AHC makes sense though.

Thanks!

 

[jLB]

Wow....I honestly did search and didn't come up with much. I have some things to learn apparently.

I have noticed other plugs in the engine bay that are not used and figured they were for heavier optioned models or the LX, but I found this location unusual. AHC makes sense though.

Thanks!

Your connector may be AHC too, but I was really responding to this portion of Greenbean's post:

I can say I have found a pigtail of wiring near the right front firewall under the hood with three plugs just sitting there unused. Wonder what they are also.

 

[flintknapper]

Wow....I honestly did search and didn't come up with much. I have some things to learn apparently.

I have noticed other plugs in the engine bay that are not used and figured they were for heavier optioned models or the LX, but I found this location unusual. AHC makes sense though.

Thanks!

delete

 

[aging fleet]

I swear I smell coolant burning at times but never in the cab, only after I'm done driving and I'm around the vehicle.

Be sure to check the plastic coolant tees at the back of the engine too.

 

[Greenbean]

Be sure to check the plastic coolant tees at the back of the engine too.

10-4, Thanks

Mine we replaced by the PO but I double checked them.