4ze1 varying charge, alternator or charge relay?

[VaJJs]

so i have an Isuzu MU 2.6L petrol 4ZE1 motor and i dont really get to use it much, i belive its an 89 model having AJ/IJ on one of the plates.
the problem is it is draining the battery dead flat and when i replaced the battery with a spare i had and chucked the multimeter on it it would be around 12.4-12.5 volts on idle but would go up to13-14 volts if i reved it a bit then would slowly go down. so is this the alternator bad or the charge relay bad? or both? and can anyone tell me where the charge relay would be? it has a bit of a powersteering leak aswell that has thrown some fluid around the engine bay could that be the cause of it? any help would be much appreciated thanks.

forgot to add, all the dash lights come on before starting and go out when started except the handbrake light.

[pig75]

My 2.6 MU is about the same with the voltages as they only have a 50A alt. By the time you have the EFI system running then lights and A/C there is not much left for the battery. No charge relay on the 2.6

[VaJJs]

oh ok, yeah i finally got a hold of a 4ze1 manual and had a good read tells me most of the stuff, so is it working normal? would it be a good idea to upgrade the alt? any suggestions what fits? i guess ill have another search around and see what i can find out. thanks.

[pig75]

Haven't bothered to upgrade yet but i would be looking at a 100A one off a common car like falcon or commodore

[muzila]

Get an 80 amp one from a bighorn. or you can get a 120 amp alt. They good for dual battrey setups.

[pig75]

Not for a 2.6 petrol

[VaJJs]

so would a commo or falcon alt just bolt in? or is there any that are just a bolt on job for the 2.6 petrol?
there is also a large area at the top of the engine above the altenator seems to have mounts there can i add a compressor there or somthing? or move the alt there?

[slightlydodgy]

My alternator on my 4ze1 was a small odd sized one I now have one out of a honda integra that bolted and pluged straight in I just took mint to the local wrecker and we went through his box of the same brand

[pig75]

No direct bolt in alt. They will need a adapter made
The area above the alt should have a air pump there that pumps air into the exhaust to reduce emissions
It should not be hard to mount a compressor there

[slightlydodgy]

The area above the alt should have a air pump there that pumps air into the exhaust to reduce emissions

Man I got a budget model thats where I put the power steer

[pig75]

I think the pump was for the Japanese emission laws

[VaJJs]

thanks for the help, i think the alternator is reasonably ok lol as long as i dont just sit with it idleing for an hour the battery stays charged, as soon as it revs over 700rpm volts go up so just normal driving keeps it charged. ill see if it eventually dies.