Voltage drop on the highway...
 

Hey guys it's me once again...
First of all this Mustang (Is this link crap the Mustangworks.com or a bug on my computer?)has come a long ways since I got it, and now it cuts out and drops voltage. I thought I fixed it by replacing a fusible link (ground of all things) that went bad off the solonoid, and now it does it again. What wires would directly cause this? It can't be more than a couple can can it? :confused:

PS: thanks for all you're help in the past, I thought I was good 'til I bought this '89! Possibly an '85 on the way as well, we'll see. :D

Re: Voltage drop on the highway...
 

Without more info, it looks like the alternator is bad.
Do you have a means to test it.....or the battery?
I would start there.

Re: Voltage drop on the highway...
 

Yeah, check the silly stuff first before you dive into the wiring. Belt slipping at higher RPM? Alt good? Voltage reg good?

If it IS a wiring problem, my guess would either be ground or field.

Re: Voltage drop on the highway...
 

The factory battery neg connection to the aluminum timing cover can experience galvanic corrosion in the threds that you can't see and cause a poor ground - found it it in mine and I switched the ground to the head.

Re: Voltage drop on the highway...
 

replace the alternator if it is stock, upgrade to a 130 amp model. _I'm looking at the powermaster alternators

Re: Voltage drop on the highway...
 

Oh yeah... had the alternator checked...32 amps! No bloody wonder! It looked brand new when I bought the car. It's a Valucraft- anything that says "value" does not belong on my car- 32 amps!!! POS!

Re: Voltage drop on the highway...
 

If you have the stock three-wire harness still on there, I would replace that while you're at it, if it were mine. I'm speaking of the connector with the larger, black wires with orange stripes. The connectors in those like to lose tension, and consequently create heat and start fires. New harnesses are available at most parts stores for this reason alone. I got sick of the low output of the stock alternators and converted it to an SN95 style. Never looked back. :)

Re: Voltage drop on the highway...
 

Yeah I've actually got a friend who had a late 80's model 5.0 T-bird... his alternator caught fire when he got to work one morning, and he worked at the local Ford dealership in the stockroom! Lmao, now that's a good place for it to happen!