Alternator getting very hot

[ryan97]

I have a new one wire 130 amp alternator from Toms that gets too hot to touch after 5 minutes. Wire to battery is cool enough to touch as is back of alternator but front is hot. Upon start up it sometimes squeals and makes 12.5 v, if you throttle it quits squealing and makes 13v. Has a new gates belt. Unfortunately the new pulley In the alternator is narrower than the old one so the belt rides higher in the grove instead of down in it more flush with the pulley. Could this be the cause? I may try and put the old pulley on this alternator? Without the belt spins freely with no noise.

 

[Viperwolf1]

Squeal is because of slipping belt. Belt slips because the alternator is trying to make more amps than belt can provide traction for. It's doing this to bring battery voltage back up after starting drew it down. When the belt slips the alternator voltage and current drops. 130 amps is too much to drive with a single v-belt. You could try a bigger diameter alt pulley or upgrade to a dual belt arrangement. The heat doesn't concern me.

Also, how are you running the alternator output? Stock wire was barely adequate for 45 amps. 130 amps in the stock wiring could cause some big problems.

 

[Steve83]

The heat up front is probably coming from the slipping belt. Either go dual, or serpentine.

 

[ryan97]

Thanks guys. It is a brand new Centech harness that I double and triple checked upon install to ensure it was correct. Every electrical item functioned properly upon test (except the voltmeter which I had downstream of the voltage regulator, once I moved that upstream) all wiring, lighting and gauges have functioned properly no arcing or sparking. Reads 12 V when off, 12.5 when squealing and 13 when quits squealing.
Based on what Viperwolf and Steve 83 say, I suspect it is because this new pulley is too narrow and not allowing the belt to seat down all the way in the groove for the most surface area contact.
I will try to fit the old pulley on the new alternator first to see if this fixes it as I know that pulley allows the stock belt to seat all the way into the pulley. I thought about changing to the old pulley on install, but I will have to put a small spacer behind it for proper clearance from the alternator housing.
On the Amperage - for the centech harness it is wired as per the 100amp diagram and I added the "optional" 6 gauge jumper for greater than 100 amps as shown by Centech. No arcing, no sparking and wires are not getting hot nor is back of alternator. Only the front housing and pulley getting hot - must be the slippage.
It is sold from Toms with a single belt pulley so I would have assumed that was enough or they would have sold it with a dual belt or wider serpentine set-up?
Thanks!

 

[lsukevinc]

not to hijack this thread, but I did upgrade my alternator to the 130 amp and I do get a squeal when the engine is cold. I do have a dual groove pulley on it. Does anyone know a part number for the second belt that run from the crank to the alternator only?

 

[welndmn]

You will find a good amount of people on here that are getting belt squeal with a 3G alt and a single belt, but there is also a ton of people who are not.
I have 4 rigs with 130 amp 3G's and no belt squal on v belts.
It does sound like you have the wrong pulley.
I run a normal autozone belt, nothing special.

 

[Broncobowsher]

The battery sounds like it is starting off with a low charge and the alternator is working full power to try and charge it. Engine off you should be over 12.5V and in the upper 13V range when the alternator backs off the output.

 

[ryan97]

Battery is 3 years old and has not been used much. Holds good charge and plenty of power for numerous cranks. Reading off of dash gauge which is a voltmeter installed in the factory cluster. Will check the off and on voltage again with an electronic voltmeter and will also look to change out pulley as a first plan of action.

 

[Steve83]

Wash all the pulleys, and if necessary, sand or sandblast them down to bare steel.

 

[DirtDonk]

And compare with a hand-held voltmeter right on the battery to make sure that you're reading of 13 on the inside gauge is the same as what you get on the other meter.
Just for comparison purposes.

Paul

 

[5001craig]

And compare with a hand-held voltmeter right on the battery to make sure that you're reading of 13 on the inside gauge is the same as what you get on the other meter.
Just for comparison purposes.

Paul

I agree with Paul (nothing unusual there).

My V-belt was constantly squealing. Was also having other electrical problems as well. Finally checked output of the stock alternator and it was putting out 17.x volts. Went with a 3g one wire and this solved my problem.

And for the record, my 3g with V-belt did not squeal.

 

[Attac]

I have a 200 3 g one wire and I had a fit with it squealing with every belt I could find. Finally figured out I didn't need that much alt but I already owned it so I had to break down and go with this belt setup. Complete serp setup but uses the same belt routing as factory. Works great now!