You're looking for the small red wire. Chances are it's disintegrating under the pulley, which is a stupid place for a wiring harness. Volvo blew it here in my opinion but we have to deal with it. Look for breaks in the insulation here or at the grey 8-pin connector on the firewall. I've had 2 cars with successful patch jobs, re-routing this wire around the right side of the engine compartment from the grey connector right to the alternator spade lug.

Also, while we're at it- do not forget your blue ground wire on the back bottom corner of the alternator. There's not a good ground path to the block since it's on rubber bushings- check that wire!

Here's where the wires run under the front of the engine:

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Rob Bareiss, New London CT ::: '87 244DL/M47- 234K, '82 245T/M46-182K, '89 244DL/AW70- 212K Not too distant past: 86 244DL 215K, 87 244DL 239K, 88 744GLE 233K, 88 244GL 147K, 91 244 183K