N14 stalls with A/C on

[Scott Mitchell]

I've got a 98 kenworth w900 with an N14 celect plus in it. Have had an issue with it since last summer. Driving down the road and at idle with the A/C on the truck will randomly die. It will fire right back up as well. Only happens with the a/c on which is why I'm lost on it. New compressor clutch and blower motor. New ecm and engine fan. Lost as to why it only happens with the a/c on...

 

[Injun]

Check your amperage draw against the alternator output with and without the A/C on. 1998s have an ECM and (without more information, I'm WAGing) can shut the whole system down on "engine protect" if it thinks there's something wrong.

 

[Scott Mitchell]

That's what I have been thinking of doing. I have had the truck for 3 years now and never replaced alternator. Beginning to think maybe alternator is too week with ac and blower motor on.

 

[Tazz]

That's what I have been thinking of doing. I have had the truck for 3 years now and never replaced alternator. Beginning to think maybe alternator is too week with ac and blower motor on.

Well it may be a power spike in the AC system as well.

Just as something I saw with later models do you have the two identical relays in your under hood box? One will say starter and one will say ignition or ecm. If you do replace them first.


Should be in the middle of the box.

 

[Scott Mitchell]

I have fused and relays out there however no box they are in. I'll check to see what they are when I fire up in the morning.

 

[Blood]

I have fused and relays out there however no box they are in.

 

[Scott Mitchell]

Lmfao yup not paying attention to what I'm writing. That's bad. Lol

 

[Tazz]

On later model Cummins they were on the firewall passenger side. But we had numerous electrical gremlins fixed by replacing the ignition (sometimes engine, or ecm labeled) relay. A sudden volt spike or drop would cause it to open killing the trucks computer.