Ali112

Hi guys what is the problem that make the red thick cable on the alternator always hot,can bad alternator rectifier make this heat

5-90

The "thick red" cable is the output cable to the rest of the vehicle. Wires usually get "too hot" for one of two reasons:

- Dirty connections. Remove each end and clean, using an emery board or a wire wheel.
- Too much current through too small of a wire. Since you don't say much more specific than you have a WJ or WK (since the ZJ didn't come with the V8-287ci,) I have to assume that you have either the 136A alternator (probably not) or the 160A alternator (likely.) What's your electrical loading like?

The OEM wiring is "acceptable for most uses" - meaning that it does fine if it sees full output from the alternator about 30% of the time - or so. If you're going to put some heavier demands on the system (lights running, stereo + subs running, winch with some heavy use,) you're going to need to go with a cable larger than OEM - since the factory put 6AWG wiring in there, that's fairly easy to do. 2AWG would be better, 1AWG would be pretty much idea, anything larger would be wasting money.

DO BEAR IN MIND THAT THAT CIRCUIT IS FUSED FROM THE FACTORY - it should have a short (~4") segment of fusible link wire just before it gets to the PDC. This may be readily identified by a moulded rubber "knuckle" covering the join between wires, the fusible link wire is physically smaller than the rest of the wire, and a different colour (not red. Fusible link wire colours are standardised, but I don't recall what colour is used for 10AWG offhand, I don't work with it much.) Therefore, you'll need to replace this protection with something functionally equivalent - ANL or MEGA fuses will serve you well here.

(NB: It's somewhat possible you may have a MEGA fuse in place, which is readily identifiable as a plastic "wafer" with a copper tab out each end, secured on two studs with nuts. These are gaining ground with OEM usage. If you do have a MEGA fuse, you probably don't need to replace it - just the wiring. If you don't have a MEGA fuse, you should have the fusible link wire - this should be replaced with ANL or MEGA fuse.)

Hit me backchannel if you'd like help.

Ali112

Thank you my friend great information you are the best,I had the wj grand overland 2004 its stock with all its original equipment

Ali112

OK thanks i will swap and change this wire,I had a bad left strap wire could this poor connection lead some sensors to work bad like knock sensor with code p0325

dave1123

Check the battery for getting hot. There is a temp sensor underneath the battery that knocks back the charge rate when the battery gets hot. It could be non-functional.